Transcript

Circular Culvert Design Calculations Software Equations

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Circular Culvert using Manning Equation

Uses Manning equation with circular culvert geometry Compute velocity discharge depth top width culvert diameter area wetted perimeter hydraulic radius Froude number Manning

coefficient channel slope

To LMNO Engineering home page (more calculations) Culvert Design using Inlet and Outlet Conrol Trapezoidal Channel Design Rectangular Channels

Unit Conversions

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Register to enable Calculate button

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Links on this page Introduction Variables Mannings n coefficients Error messages References

IntroductionThe equation beginning V= is called the Manning Equation It is a semi-empirical equation and is the most commonly used equation for uniform steady state flow of water in open channels (see Discussion and References for Open Channel Flow for further discussion) Because it is empirical the Manning equation has inconsistent units which are handled through the conversion factor k Uniform means that the water surface has the same slope as the channel bottom Uniform flow is actually only achieved in channels that are long and have an unchanging cross-section However the Manning equation is used in other situations despite not strictly achieving these conditions

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Circular Culvert Design Calculations Software Equations

In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some two require numerical solutions (Enter Q n S d and Enter V n S d) Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate to at least 8 significant digits All of our calculations utilize double precision

It is possible to get two answers using Enter QnSd or Enter VnSd This is because maximum Q and V do not occur when the pipe is full Qmax occurs when yd=0938 If yd is more than that Q actually decreases due to friction Given a pipe with diameter d roughness n and slope S let Qo be the discharge when the pipe is flowing full (yd=1) As seen on the graph below discharge is also equal to Qo when yd=082 If the entered Q is greater than Qo (but less than Qmax) there will be two solution values of yd one between 082 and 0938 and the other between 0938 and 1 The same argument applies to V except that Vo occurs at yd=05 and Vmax occurs at yd=081 If the entered V is greater than Vo (but less than Vmax) there will be two solution values of yd one between 05 and 081 and the other between 081 and 1 For further information see Chow (1959 p 134)

The following graphs are valid for any roughness (n) and slope (S) Qo=full pipe discharge Vo=full pipe velocity

Variables To top of page

A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]d = Culvert diameter [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flow with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the user Required since the Manning equation is empirical and its units

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Circular Culvert Design Calculations Software Equations

are inconsistentn = Manning coefficient n is a function of the culvert material such as plastic concrete brick etc Values for n can be found in the table below of Mannings n coefficientsP = Wetted perimeter [L] P is the contact length (in the cross-section) between the water and the culvertQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the culvert [L] If the culvert has a small slope (S) then entering the vertical depth introduces only minimal errorOslash = Angle representing how full the culvert is [radians] A culvert with Oslash=0 radians (0o) contains no water a culvert with Oslash=pi radians (180o) is half full and a culvert with Oslash=2 pi radians (360o) is completely full

Mannings n Coefficients To top of page The table shows the Manning n values for materials most commonly used for culverts These values were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references) A more complete table of Manning n values can be found on our Manning n page

Material Manning n Material Manning n

Metals

Brass 0011 Smooth Steel 0012

Cast Iron 0013 Corrugated Metal 0022

Non-Metals

Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

Glass 0010 Finished Concrete 0012

Clay Tile 0014 Unfinished Concrete 0014

Brickwork 0015 Gravel 0029

Asphalt 0016 Earth 0025

Masonry 0025 Planed Wood 0012

Unplaned Wood 0013

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Circular Culvert Design Calculations Software Equations

Error Messages To top of page Infeasible Input Td gt 1 Water top width cannot be greater than the culvert diameterAn input is lt= 0 Certain inputs must be positiveInfeasible Input T lt 0 Water top width cannot be negativeInfeasible Input yd gt 1 Water depth cannot exceed the pipe diameter

References (footnotes refer back to Manning n table) To top of page a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc

d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)Revision 0 on 12171998 Revision 1 on 7132000 (additional units)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

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Culvert Design Inlet and Outlet Control

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Culvert DesignInlet and Outlet Control

Flow thru culverts and over road or damGraph Headwater depth vs Flow

Based on HDS-5 methodology

To LMNO Engineering home page Circular Culvert using Manning Equation LMNOLMNOengcom Unit Conversions Register Trouble printing

Diagram of Flow through a Culvert

Register to fully enable Calculate buttonDemonstration mode for 09 m lt D lt 11 m and Nlt3 (D is pipe diameter N is number of pipes)

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Links on this page Introduction Equations Variables Values of Coefficients and Manning n Error Messages and Validity References

In the calculation abovemiddot Culvert Types Conc Sq edge Wall = Concrete pipe with square edged inlet and headwall Conc Groove Wall = Concrete pipe with groove end at inlet and headwall Conc Groove Proj = Concrete pipe with groove end projecting at inlet

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Culvert Design Inlet and Outlet Control

CMP Headwall = Corrugated metal pipe with headwall at inlet CMP Mitered = Corrugated metal pipe mitered to slope at inlet CMP Projecting = Corrugated metal pipe projecting at inlet

middot Unitsm=meters ft=feet ls=litersec cfm=cubic feet per minute cfs=cubic feet per second gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day MGD=Millions of US gallons per day

middot You can enter tailwater depth (Yt) as a negative number if flow from the culvert drops down to a receiving channel You dont

need to know the exact elevation drop entering any negative number for Yt will have the same effect

middot The phrase Inlet Control or Outlet Control that appears in the upper right hand corner of the calculation refers to the type of control for the total flow (Qt) entered in the calculations upper left hand corner The graph below the calculation plots headwater

depth (Yh) for the range of Qt min to Qt max entered in the bottom right hand corner The type of control may change from one part

of the graph to another as Qt changes

Introduction Culverts have been utilized for thousands of years as a means to transmit water under walkways or roads Often a culvert is simply installed without much thought to how much water it needs to convey under extreme conditions If a culvert cannot convey all of the incoming water then the water will flow over or around the pipe or simply back up behind the culvert creating a pond or reservoir If any of these conditions are unacceptable then the proper culvert diameter and number of culverts must be selected prior to installation in order to convey all of the anticipated water through the pipe(s) This calculation helps the designer size culverts as well as present a headwater depth vs discharge rating curve

The LMNO Engineering calculation is primarily based on the methodology presented in Hydraulic Design of Highway Culverts by Normann (1985) and published by the US Department of Transportations Federal Highway Administration It is also known as HDS-5 (Hydraulic Design Series No 5) HDS-5 focuses on culvert design Culvert design is usually based on the maximum acceptable discharge - thus the HDS-5 methodology is geared toward culverts flowing full with water possibly flowing over the road above the culvert In addition to programming the HDS-5 methodology LMNO Engineering wished to compute headwater depths for lesser flows Therefore in addition to the HDS-5 methodology we have added the Manning equation for culverts flowing partially full The HDS-5 methodology also assumes that the user knows the tailwater depth (Yt) before using the

methodology Though Yt can be found by field measurements it is often computed in the office using Mannings equation based on

bottom width side slopes channel roughness and channel slope Therefore LMNO Engineering added the additional feature of a built-in subroutine for computing Yt for trapezoidal channels Note that for the graphing portion of our calculation Yt is re-

computed for the entire range of flows (Qt) shown on the graph (unless the user specifically inputs Yt)

As explained in Normann 1985 (also known as HDS-5) the discharge through a culvert is controlled by either inlet or outlet conditions Inlet control means that flow through the culvert is limited by culvert entrance characteristics Outlet control means that flow through the culvert is limited by friction between the flowing water and the culvert barrel The term outlet control is a bit of a misnomer because friction along the entire length of the culvert is as important as the actual outlet condition (the tailwater depth) Inlet control most often occurs for short smooth or greatly downward sloping culverts Outlet control governs for long rough or slightly sloping culverts The type of control also depends on the flowrate For a given culvert installation inlet control may govern for a certain range of flows while outlet control may govern for other flowrates If the flowrate is large enough water could go over the road (or dam) In this case the calculation automatically computes the amount of water going over the road and through each culvert as well as the headwater depth

If you have surfed around our website you may have noticed our other calculations for circular culverts We have a calculation using Mannings equation for design of circular culverts Since it uses Mannings equation it assumes the culvert is long enough so that normal depth is achieved We also have a calculation for computing discharge from the exit depth (end depth) in a circular culvert - very useful for flowrate measurement in the field For flows under pressure we have several calculations listed under the Pipe Flow category on our home page

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Culvert Design Inlet and Outlet Control

Equations and Methodology Back to calculationThe LMNO Engineering methodology generally follows that of Normann (1985 also known as HDS-5) However the Normann methodology is mainly for culvert design Culvert design usually involves the largest expected flowrate We wanted to write a calculation that also determines headwater depth for small flowrates Therefore in addition to the Normann methodology we have incorporated Mannings equation for outlet control when the headwater depth is less than 093 times the culvert diameter 093D is used since it is the depth at which discharge through a partially full culvert is a maximum (Chow 1959) At depths greater than 093D and for full flow the Nomann (1985) equation is used for outlet control For inlet control our calculation uses Normanns equations

Many of the equations shown below are empirical and require US Customary units (feet seconds and radians) Some of the equations are based on first principles and are compatible with any consistent set of units (eg SI) However to keep this web page from being too busy we have refrained from indicating which equations are empirical and which are fundamental If you work through the equations by hand please use feet seconds and radians in all of them to avoid any problem with units [Our calculation (above) allows many different types of units the units are internally converted before and after using the equations]

Since total flowrate (Qt) is entered and headwater depth (Yh) is computed the equations below are solved simultaneously to

determine Yh Outlet versus inlet control is determined by the equation resulting in a larger value for Yh

All of the variables are defined below in the Variables section Pipe downstream invert elevation is defined as 00

General EquationsQt = Qr + N Qp Sp = Sc - Yf Lp Ei = Lp Sp Eh = Ei + Yh V=Qp Av

Tailwater Depth Yt

Yt can be computed or input If it is computed Mannings equation is used (Chow 1959)

Since Qt is input the above equations are solved numerically (backwards) for Yt

Headwater depth Yh

Yh is computed independently based on inlet and outlet control equations The equation that gives the larger value of Yh is

considered to be the controlling mechanism and is reported

Inlet Control (see below for values of constants C1 C2 C3 C4 C5)

Outlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests computing Yv using the

Manning equation If Yv is greater than D then Yv is set to D

Unsubmerged Inlet (Normann 1985)

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Culvert Design Inlet and Outlet Control

Submerged Inlet (Normann 1985)

Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

If Yhlt093D then Mannings equation (Chow 1959) is used

Since Qp is input the above equations are solved numerically for Yt

If Yhgt=093D Normann (1985) is used

Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

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Culvert Design Inlet and Outlet Control

Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

Variables Back to calculation

A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

Av=Flow area in one pipe used for computing outlet velocity [ft2]

b=Width of channel bottom [ft] Used for computing Yt

C1 C2 C3 C4 C5=Constants for inlet control equations See values below

D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

(not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

the roadnc=Channel Manning n coefficient See values below

np=Pipe (culvert) Manning n coefficient See values below

N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

Qr=Flowrate over the road (or dam) [cfs]

Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

Tc=Top width of flow in one pipe based on critical depth [ft]

V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

Yavg=Average water depth [ft]

Yc=Critical water depth [ft]

Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

Yh=Headwater depth [ft]

Yo=Water outlet depth [ft]

Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

Yv=Depth used for computing outlet velocity [ft]

z1=Left side slope of existing natural channel [horizontalvertical]

z2=Right side slope of existing natural channel [horizontalvertical]

Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

Ke are from Normann (1985)

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Culvert Design Inlet and Outlet Control

Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

Clean and Straight 0030 Clean 0022

Major Rivers 0035 Gravelly 0025

Sluggish with Deep Pools 0040 Weedy 0030

Stony Cobbles 0035

Floodplains

Pasture Farmland 0035 Heavy Brush 0075

Light Brush 0050 Trees 015

Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

side slopesNeed Scgt0 Channel cannot be horizontal

Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

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Culvert Design Inlet and Outlet Control

Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

minimum and maximum are too close together to have good axis labels for the graph

Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

YtgtEr since the equations are only valid for Ytlt=Er

References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

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Design of Circular Water Pipes using Hazen Williams Equation

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Design of Circular Pressurized Water Pipes

Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

LMNO Engineering home page Unit Conversions Page Trouble printing

Register to enable Calculate button

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Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

Piping Scenarios

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Design of Circular Water Pipes using Hazen Williams Equation

Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

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Design of Circular Water Pipes using Hazen Williams Equation

Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

Steady State Energy Equation used for this page Back to CalculationsObtained from References

Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

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Design of Circular Water Pipes using Hazen Williams Equation

Material C Material C

Asbestos Cement 140 Copper 130-140

Brass 130-140 Galvanized iron 120

Brick sewer 100 Glass 140

Cast-Iron Lead 130-140

New unlined 130 Plastic 140-150

10 yr old 107-113 Steel

20 yr old 89-100 Coal-tar enamel lined 145-150

30 yr old 75-90 New unlined 140-150

40 yr old 64-83 Riveted 110

ConcreteConcrete-lined

Steel forms 140 Tin 130

Wooden forms 120 Vitrif clay (good condition) 110-140

Centrifugally spun 135 Wood stave (avg condition) 120

Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

Fitting Km Fitting Km

Valves Elbows

Globe fully open 10 Regular 90deg flanged 03

Angle fully open 2 Regular 90deg threaded 15

Gate fully open 015 Long radius 90deg flanged 02

Gate 14 closed 026 Long radius 90deg threaded 07

Gate 12 closed 21 Long radius 45deg threaded 02

Gate 34 closed 17 Regular 45deg threaded 04

Swing check forward flow 2

Swing check backward flow infinity Tees

Line flow flanged 02

180deg return bends Line flow threaded 09

Flanged 02 Branch flow flanged 10

Threaded 15 Branch flow threaded 20

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Design of Circular Water Pipes using Hazen Williams Equation

Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

Square Connection 05 Square Connection 10

Rounded Connection 02 Rounded Connection 10

Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

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DPlot Graphing Software for Scientists and Engineers - Home Page

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Gradually Varied Flow Calculation Backwater profile

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Gradually Varied Flow in Trapezoidal Channel

Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

Compute normal and critical depths

To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

Cross-Section of Trapezoidal Channel

Gradually Varied Flow Profiles

CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

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middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

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Gradually Varied Flow Calculation Backwater profile

Links on this page Equations Variables Manning n coefficients Error messages References

Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

1985) along with the fundamental equations above to solve for Yc

Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

critical (C) The slopes are further classified by a number (1 2 or 3) as follows

For mild slopes (YngtYc)

If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

water depth gets closer to Yn as the calculation proceeds further and further upstream

If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

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Gradually Varied Flow Calculation Backwater profile

The water depth gets closer to Yn as the calculation proceeds further and further upstream

If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

For steep slopes (YcgtYn)

If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

water depth gets closer to Yn as the calculation proceeds further and further downstream

If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

water depth gets closer to Yn as the calculation proceeds further and further downstream

For critical slopes (Yc=Yn)

If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

water depth gets closer to Yn as the calculation proceeds further and further upstream

If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

water depth gets closer to Yn as the calculation proceeds further and further downstream

There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

At control section i=1 and Yi=Ys

Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

differential depth increments (this is the basis of the Improved Euler method)

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Gradually Varied Flow Calculation Backwater profile

Then repeat the loop by incrementing i

The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

Ap=Area at Xp [m2]

A2=Area for intermediate computation in Improved Euler method [m2]

dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

(dYdX)2=Second depth increment for Improved Euler method [m]

B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

Epy=Elevation of water surface at Xp [m]

F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

P2=Second wetted perimeter computed in Improved Euler method [m]

Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

Sf1=First energy slope for Improved Euler method [dimensionless]

Sf2=Second energy slope for Improved Euler method [dimensionless]

T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

T2=Second top width computed in Improved Euler method [m]

Tp=Top width at Xp [m]

V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

automatically set Xp to Xmax

Y=Water depth [m]Yc=Critical depth [m]

Yi=Water depth computed at successive i intervals in Improved Euler method [m]

Yn=Normal depth [m]

Yp=Depth at Xp [m]

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Gradually Varied Flow Calculation Backwater profile

Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

Y2=Second depth computed in Improved Euler method [m]

Z1=One channel side slope (horizontal to vertical ratio) [mm]

Z2=The other channel side slope (horizontal to vertical ratio) [mm]

Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

Material Manning n Material Manning n

Natural Streams Excavated Earth Channels

Clean and Straight 0030 Clean 0022

Major Rivers 0035 Gravelly 0025

Sluggish with Deep Pools 0040 Weedy 0030

Stony Cobbles 0035

Metals Floodplains

Brass 0011 Pasture Farmland 0035

Cast Iron 0013 Light Brush 0050

Smooth Steel 0012 Heavy Brush 0075

Corrugated Metal 0022 Trees 015

Non-Metals

Glass 0010 Finished Concrete 0012

Clay Tile 0014 Unfinished Concrete 0014

Brickwork 0015 Gravel 0029

Asphalt 0016 Earth 0025

Masonry 0025 Planed Wood 0012

Unplaned Wood 0013

Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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Gradually Varied Flow Calculation Backwater profile

Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

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Hydraulic Jump Calculation

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Hydraulic Jump in Horizontal Rectangular Channel

Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

jump length and energy loss

To LMNO Engineering home page (all calculations) Related open channel calculations

Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

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Hydraulic Jump Calculation

Register to enable Calculate button

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Equations

Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

What is a Hydraulic Jump

A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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Hydraulic Jump Calculation

MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

Need F1 gt1 Upstream flow must be supercritical

ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

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Manning Equation

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Mannings Equation Calculator Software The open channel flow software website

LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

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The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

The product AP is also known as the hydraulic radius Rh

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Non-Circular Open Channel Geometry

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Geometric Calculations for Non-Circular Partially Filled Channels

The open channel flow calculations software website

Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

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You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

Equations (note that R=AP)

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Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

losses

Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

pipe Dont have to use all the pipes or nodes

To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

Register to fully enable Calculate button

Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

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Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

Pipe flows are adjusted iteratively using the following equation

until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

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Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

where log is base 10 logarithm and ln is natural logarithm Variable definitions

Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

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For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

ApplicationsThe pipe network calculation has many applications Two examples will be provided

1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

bull

Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

Weisbach - Moody friction losses)

Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

(using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

Parabolic shaped pump curve is formed from the two points

ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

curve Hazen-Williams with pump curve

Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

Register to enable Calculate button

Your browser does not support Java or Java is disabled in your browser Calculation should be here

Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

(obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

calculation will look like

The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

defined for liquids

Variables Units F=force L=length P=pressure T=time Back to Calculations

Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

hf = Major losses for entire pipe [L] Also known as friction losses

hfA = Major losses for pipe upstream of pump (pipe A) only [L]

hm = Minor losses for entire pipe [L]

hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

Fitting K Fitting K

Valves Elbows

Globe fully open 10 Regular 90deg flanged 03

Angle fully open 2 Regular 90deg threaded 15

Gate fully open 015 Long radius 90deg flanged 02

Gate 14 closed 026 Long radius 90deg threaded 07

Gate 12 closed 21 Long radius 45deg threaded 02

Gate 34 closed 17 Regular 45deg threaded 04

Swing check forward flow 2

Swing check backward flow infinity Tees

Line flow flanged 02

180deg return bends Line flow threaded 09

Flanged 02 Branch flow flanged 10

Threaded 15 Branch flow threaded 20

Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

Square Connection 05 Square Connection 10

Rounded Connection 02 Rounded Connection 10

Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

the pipe or K for the suction pipe was entered as greater than K for the entire system

Other messagesK must be gt=1 If Q known Solve for D and V

3=0 then K must be gt 1 in order to solve

Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

reservoirs are defined to be at zero pressure thus zero pressure difference

Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

White F M 1979 Fluid Mechanics McGraw-Hill Inc

copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

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Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

bull

Circular Pressurized Water Pipes with Pump Curve

(Hazen Williams)

Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

(using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

curve Darcy-Weisbach with pump curve

Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

Register to enable Calculate button

Your browser does not support Java or Java is disabled in your browser Calculation should be here

Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

Equations and Methodology Back to Calculations

fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

calculation will look like

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Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

Variables Units L=length P=pressure T=time Back to Calculations

A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

hf = Major losses for entire pipe [L]

hfA = Major losses for pipe upstream of pump (pipe A) only [L]

hm = Minor losses for entire pipe [L]

hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

Material C Material C

Asbestos Cement 140 Copper 130-140

Brass 130-140 Galvanized iron 120

Brick sewer 100 Glass 140

Cast-Iron Lead 130-140

New unlined 130 Plastic 140-150

10 yr old 107-113 Steel

20 yr old 89-100 Coal-tar enamel lined 145-150

30 yr old 75-90 New unlined 140-150

40 yr old 64-83 Riveted 110

ConcreteConcrete-lined

Steel forms 140 Tin 130

Wooden forms 120 Vitrif clay (good condition) 110-140

Centrifugally spun 135 Wood stave (avg condition) 120

Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

Fitting K Fitting K

Valves Elbows

Globe fully open 10 Regular 90deg flanged 03

Angle fully open 2 Regular 90deg threaded 15

Gate fully open 015 Long radius 90deg flanged 02

Gate 14 closed 026 Long radius 90deg threaded 07

Gate 12 closed 21 Long radius 45deg threaded 02

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Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

Gate 34 closed 17 Regular 45deg threaded 04

Swing check forward flow 2

Swing check backward flow infinity Tees

Line flow flanged 02

180deg return bends Line flow threaded 09

Flanged 02 Branch flow flanged 10

Threaded 15 Branch flow threaded 20

Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

Square Connection 05 Square Connection 10

Rounded Connection 02 Rounded Connection 10

Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

LMNOLMNOengcom httpwwwlmnoengcom

fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

bull

Trapezoidal Open Channel Design Calculation

Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

Froude number Manning coefficient channel slope

To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

Register to enable Calculate button

Your browser does not support Java or Java is disabled in your browser Calculation should be here

Links on this page Introduction Variables Manning n coefficients Error Messages References

IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

Variables [] indicates dimensions To calculation

A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

divided by vertical distance

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Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

Oslash = Angle formed by S

Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

Material Manning n Material Manning n

Natural Streams Excavated Earth Channels

Clean and Straight 0030 Clean 0022

Major Rivers 0035 Gravelly 0025

Sluggish with Deep Pools 0040 Weedy 0030

Stony Cobbles 0035

Metals Floodplains

Brass 0011 Pasture Farmland 0035

Cast Iron 0013 Light Brush 0050

Smooth Steel 0012 Heavy Brush 0075

Corrugated Metal 0022 Trees 015

Non-Metals

Glass 0010 Finished Concrete 0012

Clay Tile 0014 Unfinished Concrete 0014

Brickwork 0015 Gravel 0029

Asphalt 0016 Earth 0025

Masonry 0025 Planed Wood 0012

Unplaned Wood 0013

Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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Waterhammer surge analysis and transient analysis pipe flow modeling software

Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

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AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

Waterhammer surge analysis and transient analysis pipe flow modeling software

components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

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copy 2001-2007 Applied Flow Technology All Rights Reserved

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  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
    • Local Disk
      • Circular Culvert Design Calculations Software Equations
          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
            • Local Disk
              • Culvert Design Inlet and Outlet Control
                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                    • Local Disk
                      • Design of Circular Water Pipes using Hazen Williams Equation
                          • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                            • Local Disk
                              • DPlot Graphing Software for Scientists and Engineers - Home Page
                                  • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                    • Local Disk
                                      • Gradually Varied Flow Calculation Backwater profile
                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                            • Local Disk
                                              • Hydraulic Jump Calculation
                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
                                                    • Local Disk
                                                      • Manning Equation
                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                            • Local Disk
                                                              • Non-Circular Open Channel Geometry
                                                                  • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                    • Local Disk
                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                            • Local Disk
                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                  • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                            • Local Disk
                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                    • Local Disk
                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

    Circular Culvert Design Calculations Software Equations

    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some two require numerical solutions (Enter Q n S d and Enter V n S d) Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate to at least 8 significant digits All of our calculations utilize double precision

    It is possible to get two answers using Enter QnSd or Enter VnSd This is because maximum Q and V do not occur when the pipe is full Qmax occurs when yd=0938 If yd is more than that Q actually decreases due to friction Given a pipe with diameter d roughness n and slope S let Qo be the discharge when the pipe is flowing full (yd=1) As seen on the graph below discharge is also equal to Qo when yd=082 If the entered Q is greater than Qo (but less than Qmax) there will be two solution values of yd one between 082 and 0938 and the other between 0938 and 1 The same argument applies to V except that Vo occurs at yd=05 and Vmax occurs at yd=081 If the entered V is greater than Vo (but less than Vmax) there will be two solution values of yd one between 05 and 081 and the other between 081 and 1 For further information see Chow (1959 p 134)

    The following graphs are valid for any roughness (n) and slope (S) Qo=full pipe discharge Vo=full pipe velocity

    Variables To top of page

    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]d = Culvert diameter [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flow with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the user Required since the Manning equation is empirical and its units

    fileE|engineeringhydraulicsCircular20Culvert2sign20Calculations20-20Software20-20Equationshtm (2 of 4)12112007 40251 PM

    Circular Culvert Design Calculations Software Equations

    are inconsistentn = Manning coefficient n is a function of the culvert material such as plastic concrete brick etc Values for n can be found in the table below of Mannings n coefficientsP = Wetted perimeter [L] P is the contact length (in the cross-section) between the water and the culvertQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the culvert [L] If the culvert has a small slope (S) then entering the vertical depth introduces only minimal errorOslash = Angle representing how full the culvert is [radians] A culvert with Oslash=0 radians (0o) contains no water a culvert with Oslash=pi radians (180o) is half full and a culvert with Oslash=2 pi radians (360o) is completely full

    Mannings n Coefficients To top of page The table shows the Manning n values for materials most commonly used for culverts These values were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references) A more complete table of Manning n values can be found on our Manning n page

    Material Manning n Material Manning n

    Metals

    Brass 0011 Smooth Steel 0012

    Cast Iron 0013 Corrugated Metal 0022

    Non-Metals

    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

    Glass 0010 Finished Concrete 0012

    Clay Tile 0014 Unfinished Concrete 0014

    Brickwork 0015 Gravel 0029

    Asphalt 0016 Earth 0025

    Masonry 0025 Planed Wood 0012

    Unplaned Wood 0013

    fileE|engineeringhydraulicsCircular20Culvert2sign20Calculations20-20Software20-20Equationshtm (3 of 4)12112007 40251 PM

    Circular Culvert Design Calculations Software Equations

    Error Messages To top of page Infeasible Input Td gt 1 Water top width cannot be greater than the culvert diameterAn input is lt= 0 Certain inputs must be positiveInfeasible Input T lt 0 Water top width cannot be negativeInfeasible Input yd gt 1 Water depth cannot exceed the pipe diameter

    References (footnotes refer back to Manning n table) To top of page a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

    Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc

    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

    copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)Revision 0 on 12171998 Revision 1 on 7132000 (additional units)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

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    Culvert Design Inlet and Outlet Control

    bull

    Culvert DesignInlet and Outlet Control

    Flow thru culverts and over road or damGraph Headwater depth vs Flow

    Based on HDS-5 methodology

    To LMNO Engineering home page Circular Culvert using Manning Equation LMNOLMNOengcom Unit Conversions Register Trouble printing

    Diagram of Flow through a Culvert

    Register to fully enable Calculate buttonDemonstration mode for 09 m lt D lt 11 m and Nlt3 (D is pipe diameter N is number of pipes)

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    Links on this page Introduction Equations Variables Values of Coefficients and Manning n Error Messages and Validity References

    In the calculation abovemiddot Culvert Types Conc Sq edge Wall = Concrete pipe with square edged inlet and headwall Conc Groove Wall = Concrete pipe with groove end at inlet and headwall Conc Groove Proj = Concrete pipe with groove end projecting at inlet

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    Culvert Design Inlet and Outlet Control

    CMP Headwall = Corrugated metal pipe with headwall at inlet CMP Mitered = Corrugated metal pipe mitered to slope at inlet CMP Projecting = Corrugated metal pipe projecting at inlet

    middot Unitsm=meters ft=feet ls=litersec cfm=cubic feet per minute cfs=cubic feet per second gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day MGD=Millions of US gallons per day

    middot You can enter tailwater depth (Yt) as a negative number if flow from the culvert drops down to a receiving channel You dont

    need to know the exact elevation drop entering any negative number for Yt will have the same effect

    middot The phrase Inlet Control or Outlet Control that appears in the upper right hand corner of the calculation refers to the type of control for the total flow (Qt) entered in the calculations upper left hand corner The graph below the calculation plots headwater

    depth (Yh) for the range of Qt min to Qt max entered in the bottom right hand corner The type of control may change from one part

    of the graph to another as Qt changes

    Introduction Culverts have been utilized for thousands of years as a means to transmit water under walkways or roads Often a culvert is simply installed without much thought to how much water it needs to convey under extreme conditions If a culvert cannot convey all of the incoming water then the water will flow over or around the pipe or simply back up behind the culvert creating a pond or reservoir If any of these conditions are unacceptable then the proper culvert diameter and number of culverts must be selected prior to installation in order to convey all of the anticipated water through the pipe(s) This calculation helps the designer size culverts as well as present a headwater depth vs discharge rating curve

    The LMNO Engineering calculation is primarily based on the methodology presented in Hydraulic Design of Highway Culverts by Normann (1985) and published by the US Department of Transportations Federal Highway Administration It is also known as HDS-5 (Hydraulic Design Series No 5) HDS-5 focuses on culvert design Culvert design is usually based on the maximum acceptable discharge - thus the HDS-5 methodology is geared toward culverts flowing full with water possibly flowing over the road above the culvert In addition to programming the HDS-5 methodology LMNO Engineering wished to compute headwater depths for lesser flows Therefore in addition to the HDS-5 methodology we have added the Manning equation for culverts flowing partially full The HDS-5 methodology also assumes that the user knows the tailwater depth (Yt) before using the

    methodology Though Yt can be found by field measurements it is often computed in the office using Mannings equation based on

    bottom width side slopes channel roughness and channel slope Therefore LMNO Engineering added the additional feature of a built-in subroutine for computing Yt for trapezoidal channels Note that for the graphing portion of our calculation Yt is re-

    computed for the entire range of flows (Qt) shown on the graph (unless the user specifically inputs Yt)

    As explained in Normann 1985 (also known as HDS-5) the discharge through a culvert is controlled by either inlet or outlet conditions Inlet control means that flow through the culvert is limited by culvert entrance characteristics Outlet control means that flow through the culvert is limited by friction between the flowing water and the culvert barrel The term outlet control is a bit of a misnomer because friction along the entire length of the culvert is as important as the actual outlet condition (the tailwater depth) Inlet control most often occurs for short smooth or greatly downward sloping culverts Outlet control governs for long rough or slightly sloping culverts The type of control also depends on the flowrate For a given culvert installation inlet control may govern for a certain range of flows while outlet control may govern for other flowrates If the flowrate is large enough water could go over the road (or dam) In this case the calculation automatically computes the amount of water going over the road and through each culvert as well as the headwater depth

    If you have surfed around our website you may have noticed our other calculations for circular culverts We have a calculation using Mannings equation for design of circular culverts Since it uses Mannings equation it assumes the culvert is long enough so that normal depth is achieved We also have a calculation for computing discharge from the exit depth (end depth) in a circular culvert - very useful for flowrate measurement in the field For flows under pressure we have several calculations listed under the Pipe Flow category on our home page

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    Culvert Design Inlet and Outlet Control

    Equations and Methodology Back to calculationThe LMNO Engineering methodology generally follows that of Normann (1985 also known as HDS-5) However the Normann methodology is mainly for culvert design Culvert design usually involves the largest expected flowrate We wanted to write a calculation that also determines headwater depth for small flowrates Therefore in addition to the Normann methodology we have incorporated Mannings equation for outlet control when the headwater depth is less than 093 times the culvert diameter 093D is used since it is the depth at which discharge through a partially full culvert is a maximum (Chow 1959) At depths greater than 093D and for full flow the Nomann (1985) equation is used for outlet control For inlet control our calculation uses Normanns equations

    Many of the equations shown below are empirical and require US Customary units (feet seconds and radians) Some of the equations are based on first principles and are compatible with any consistent set of units (eg SI) However to keep this web page from being too busy we have refrained from indicating which equations are empirical and which are fundamental If you work through the equations by hand please use feet seconds and radians in all of them to avoid any problem with units [Our calculation (above) allows many different types of units the units are internally converted before and after using the equations]

    Since total flowrate (Qt) is entered and headwater depth (Yh) is computed the equations below are solved simultaneously to

    determine Yh Outlet versus inlet control is determined by the equation resulting in a larger value for Yh

    All of the variables are defined below in the Variables section Pipe downstream invert elevation is defined as 00

    General EquationsQt = Qr + N Qp Sp = Sc - Yf Lp Ei = Lp Sp Eh = Ei + Yh V=Qp Av

    Tailwater Depth Yt

    Yt can be computed or input If it is computed Mannings equation is used (Chow 1959)

    Since Qt is input the above equations are solved numerically (backwards) for Yt

    Headwater depth Yh

    Yh is computed independently based on inlet and outlet control equations The equation that gives the larger value of Yh is

    considered to be the controlling mechanism and is reported

    Inlet Control (see below for values of constants C1 C2 C3 C4 C5)

    Outlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests computing Yv using the

    Manning equation If Yv is greater than D then Yv is set to D

    Unsubmerged Inlet (Normann 1985)

    fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (3 of 7)12112007 40331 PM

    Culvert Design Inlet and Outlet Control

    Submerged Inlet (Normann 1985)

    Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

    YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

    If Yhlt093D then Mannings equation (Chow 1959) is used

    Since Qp is input the above equations are solved numerically for Yt

    If Yhgt=093D Normann (1985) is used

    Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

    fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (4 of 7)12112007 40331 PM

    Culvert Design Inlet and Outlet Control

    Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

    Variables Back to calculation

    A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

    Av=Flow area in one pipe used for computing outlet velocity [ft2]

    b=Width of channel bottom [ft] Used for computing Yt

    C1 C2 C3 C4 C5=Constants for inlet control equations See values below

    D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

    Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

    Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

    g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

    Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

    (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

    the roadnc=Channel Manning n coefficient See values below

    np=Pipe (culvert) Manning n coefficient See values below

    N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

    Qr=Flowrate over the road (or dam) [cfs]

    Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

    Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

    Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

    Tc=Top width of flow in one pipe based on critical depth [ft]

    V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

    Yavg=Average water depth [ft]

    Yc=Critical water depth [ft]

    Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

    Yh=Headwater depth [ft]

    Yo=Water outlet depth [ft]

    Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

    Yv=Depth used for computing outlet velocity [ft]

    z1=Left side slope of existing natural channel [horizontalvertical]

    z2=Right side slope of existing natural channel [horizontalvertical]

    Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

    Ke are from Normann (1985)

    fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (5 of 7)12112007 40331 PM

    Culvert Design Inlet and Outlet Control

    Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

    Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

    Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

    Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

    Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

    Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

    Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

    Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

    Clean and Straight 0030 Clean 0022

    Major Rivers 0035 Gravelly 0025

    Sluggish with Deep Pools 0040 Weedy 0030

    Stony Cobbles 0035

    Floodplains

    Pasture Farmland 0035 Heavy Brush 0075

    Light Brush 0050 Trees 015

    Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

    Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

    Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

    the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

    Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

    discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

    side slopesNeed Scgt0 Channel cannot be horizontal

    Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

    is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

    Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

    fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

    Culvert Design Inlet and Outlet Control

    Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

    Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

    Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

    minimum and maximum are too close together to have good axis labels for the graph

    Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

    YtgtEr since the equations are only valid for Ytlt=Er

    References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

    French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

    Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

    fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

    Design of Circular Water Pipes using Hazen Williams Equation

    bull

    Design of Circular Pressurized Water Pipes

    Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

    ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

    Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

    LMNO Engineering home page Unit Conversions Page Trouble printing

    Register to enable Calculate button

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

    Piping Scenarios

    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

    Design of Circular Water Pipes using Hazen Williams Equation

    Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

    Design of Circular Water Pipes using Hazen Williams Equation

    Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

    Steady State Energy Equation used for this page Back to CalculationsObtained from References

    Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

    k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

    Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

    Design of Circular Water Pipes using Hazen Williams Equation

    Material C Material C

    Asbestos Cement 140 Copper 130-140

    Brass 130-140 Galvanized iron 120

    Brick sewer 100 Glass 140

    Cast-Iron Lead 130-140

    New unlined 130 Plastic 140-150

    10 yr old 107-113 Steel

    20 yr old 89-100 Coal-tar enamel lined 145-150

    30 yr old 75-90 New unlined 140-150

    40 yr old 64-83 Riveted 110

    ConcreteConcrete-lined

    Steel forms 140 Tin 130

    Wooden forms 120 Vitrif clay (good condition) 110-140

    Centrifugally spun 135 Wood stave (avg condition) 120

    Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

    Fitting Km Fitting Km

    Valves Elbows

    Globe fully open 10 Regular 90deg flanged 03

    Angle fully open 2 Regular 90deg threaded 15

    Gate fully open 015 Long radius 90deg flanged 02

    Gate 14 closed 026 Long radius 90deg threaded 07

    Gate 12 closed 21 Long radius 45deg threaded 02

    Gate 34 closed 17 Regular 45deg threaded 04

    Swing check forward flow 2

    Swing check backward flow infinity Tees

    Line flow flanged 02

    180deg return bends Line flow threaded 09

    Flanged 02 Branch flow flanged 10

    Threaded 15 Branch flow threaded 20

    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

    Design of Circular Water Pipes using Hazen Williams Equation

    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

    Square Connection 05 Square Connection 10

    Rounded Connection 02 Rounded Connection 10

    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

    copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

    GRAPH SOFTWARE FOR SCIENTISTS amp ENGINEERS

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    Compatible with Windowsreg 95 98 2000 ME NT 2003 XP and Vista

    DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

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    DPlot Graphing Software for Scientists and Engineers - Home Page

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    DPlot Graphing Software for Scientists and Engineers - Home Page

    or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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    Gradually Varied Flow Calculation Backwater profile

    bull

    Gradually Varied Flow in Trapezoidal Channel

    Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

    Compute normal and critical depths

    To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

    LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

    Cross-Section of Trapezoidal Channel

    Gradually Varied Flow Profiles

    CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

    middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

    Gradually Varied Flow Calculation Backwater profile

    Links on this page Equations Variables Manning n coefficients Error messages References

    Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

    equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

    calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

    The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

    Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

    using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

    References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

    empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

    Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

    Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

    1985) along with the fundamental equations above to solve for Yc

    Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

    the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

    Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

    critical (C) The slopes are further classified by a number (1 2 or 3) as follows

    For mild slopes (YngtYc)

    If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

    water depth gets closer to Yn as the calculation proceeds further and further upstream

    If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

    Gradually Varied Flow Calculation Backwater profile

    The water depth gets closer to Yn as the calculation proceeds further and further upstream

    If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

    is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

    For steep slopes (YcgtYn)

    If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

    is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

    If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

    water depth gets closer to Yn as the calculation proceeds further and further downstream

    If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

    water depth gets closer to Yn as the calculation proceeds further and further downstream

    For critical slopes (Yc=Yn)

    If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

    water depth gets closer to Yn as the calculation proceeds further and further upstream

    If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

    water depth gets closer to Yn as the calculation proceeds further and further downstream

    There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

    Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

    At control section i=1 and Yi=Ys

    Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

    Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

    Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

    P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

    differential depth increments (this is the basis of the Improved Euler method)

    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

    Gradually Varied Flow Calculation Backwater profile

    Then repeat the loop by incrementing i

    The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

    Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

    Ap=Area at Xp [m2]

    A2=Area for intermediate computation in Improved Euler method [m2]

    dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

    (dYdX)2=Second depth increment for Improved Euler method [m]

    B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

    Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

    Epy=Elevation of water surface at Xp [m]

    F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

    g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

    P2=Second wetted perimeter computed in Improved Euler method [m]

    Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

    Sf1=First energy slope for Improved Euler method [dimensionless]

    Sf2=Second energy slope for Improved Euler method [dimensionless]

    T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

    T2=Second top width computed in Improved Euler method [m]

    Tp=Top width at Xp [m]

    V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

    X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

    is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

    Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

    automatically set Xp to Xmax

    Y=Water depth [m]Yc=Critical depth [m]

    Yi=Water depth computed at successive i intervals in Improved Euler method [m]

    Yn=Normal depth [m]

    Yp=Depth at Xp [m]

    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

    Gradually Varied Flow Calculation Backwater profile

    Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

    Y2=Second depth computed in Improved Euler method [m]

    Z1=One channel side slope (horizontal to vertical ratio) [mm]

    Z2=The other channel side slope (horizontal to vertical ratio) [mm]

    Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

    Material Manning n Material Manning n

    Natural Streams Excavated Earth Channels

    Clean and Straight 0030 Clean 0022

    Major Rivers 0035 Gravelly 0025

    Sluggish with Deep Pools 0040 Weedy 0030

    Stony Cobbles 0035

    Metals Floodplains

    Brass 0011 Pasture Farmland 0035

    Cast Iron 0013 Light Brush 0050

    Smooth Steel 0012 Heavy Brush 0075

    Corrugated Metal 0022 Trees 015

    Non-Metals

    Glass 0010 Finished Concrete 0012

    Clay Tile 0014 Unfinished Concrete 0014

    Brickwork 0015 Gravel 0029

    Asphalt 0016 Earth 0025

    Masonry 0025 Planed Wood 0012

    Unplaned Wood 0013

    Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

    20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

    Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

    Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

    is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

    References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

    Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

    Gradually Varied Flow Calculation Backwater profile

    Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

    French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

    Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

    Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

    Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

    Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

    copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

    Hydraulic Jump Calculation

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    Hydraulic Jump in Horizontal Rectangular Channel

    Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

    jump length and energy loss

    To LMNO Engineering home page (all calculations) Related open channel calculations

    Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

    Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

    fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

    Hydraulic Jump Calculation

    Register to enable Calculate button

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    Equations

    Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

    V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

    L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

    where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

    Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

    What is a Hydraulic Jump

    A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

    According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

    oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

    occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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    Hydraulic Jump Calculation

    MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

    Need F1 gt1 Upstream flow must be supercritical

    ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

    copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

    fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

    Manning Equation

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    Mannings Equation Calculator Software The open channel flow software website

    LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

    Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

    and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

    The product AP is also known as the hydraulic radius Rh

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    Non-Circular Open Channel Geometry

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    Geometric Calculations for Non-Circular Partially Filled Channels

    The open channel flow calculations software website

    Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

    Equations (note that R=AP)

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    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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    Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

    losses

    Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

    pipe Dont have to use all the pipes or nodes

    To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

    Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

    Register to fully enable Calculate button

    Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

    IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

    Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

    The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

    Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

    Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

    1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

    Pipe flows are adjusted iteratively using the following equation

    until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

    Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

    Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

    Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

    where log is base 10 logarithm and ln is natural logarithm Variable definitions

    Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

    Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

    Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

    Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

    The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

    ApplicationsThe pipe network calculation has many applications Two examples will be provided

    1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

    pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

    2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

    Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

    Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

    Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

    A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

    n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

    Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

    Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

    References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

    Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

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    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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    Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

    Weisbach - Moody friction losses)

    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

    (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

    Parabolic shaped pump curve is formed from the two points

    ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

    curve Hazen-Williams with pump curve

    Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

    Register to enable Calculate button

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

    IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

    A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

    For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

    (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

    Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

    Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

    calculation will look like

    The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

    Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

    Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

    is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

    defined for liquids

    Variables Units F=force L=length P=pressure T=time Back to Calculations

    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

    is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

    A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

    hf = Major losses for entire pipe [L] Also known as friction losses

    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

    hm = Minor losses for entire pipe [L]

    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

    K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

    for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

    P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

    location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

    zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

    V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

    this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

    v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

    Fitting K Fitting K

    Valves Elbows

    Globe fully open 10 Regular 90deg flanged 03

    Angle fully open 2 Regular 90deg threaded 15

    Gate fully open 015 Long radius 90deg flanged 02

    Gate 14 closed 026 Long radius 90deg threaded 07

    Gate 12 closed 21 Long radius 45deg threaded 02

    Gate 34 closed 17 Regular 45deg threaded 04

    Swing check forward flow 2

    Swing check backward flow infinity Tees

    Line flow flanged 02

    180deg return bends Line flow threaded 09

    Flanged 02 Branch flow flanged 10

    Threaded 15 Branch flow threaded 20

    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

    Square Connection 05 Square Connection 10

    Rounded Connection 02 Rounded Connection 10

    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

    Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

    The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

    Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

    the pipe or K for the suction pipe was entered as greater than K for the entire system

    Other messagesK must be gt=1 If Q known Solve for D and V

    3=0 then K must be gt 1 in order to solve

    Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

    reservoirs are defined to be at zero pressure thus zero pressure difference

    Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

    Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

    References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

    Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

    Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

    Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

    Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

    White F M 1979 Fluid Mechanics McGraw-Hill Inc

    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    bull

    Circular Pressurized Water Pipes with Pump Curve

    (Hazen Williams)

    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

    (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

    ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

    curve Darcy-Weisbach with pump curve

    Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

    Register to enable Calculate button

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

    IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

    function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

    manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

    Equations and Methodology Back to Calculations

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

    calculation will look like

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

    Variables Units L=length P=pressure T=time Back to Calculations

    A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

    g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

    hf = Major losses for entire pipe [L]

    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

    hm = Minor losses for entire pipe [L]

    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

    k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

    L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

    program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

    location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

    zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

    this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

    Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

    available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

    and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

    Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

    Material C Material C

    Asbestos Cement 140 Copper 130-140

    Brass 130-140 Galvanized iron 120

    Brick sewer 100 Glass 140

    Cast-Iron Lead 130-140

    New unlined 130 Plastic 140-150

    10 yr old 107-113 Steel

    20 yr old 89-100 Coal-tar enamel lined 145-150

    30 yr old 75-90 New unlined 140-150

    40 yr old 64-83 Riveted 110

    ConcreteConcrete-lined

    Steel forms 140 Tin 130

    Wooden forms 120 Vitrif clay (good condition) 110-140

    Centrifugally spun 135 Wood stave (avg condition) 120

    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

    Fitting K Fitting K

    Valves Elbows

    Globe fully open 10 Regular 90deg flanged 03

    Angle fully open 2 Regular 90deg threaded 15

    Gate fully open 015 Long radius 90deg flanged 02

    Gate 14 closed 026 Long radius 90deg threaded 07

    Gate 12 closed 21 Long radius 45deg threaded 02

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    Gate 34 closed 17 Regular 45deg threaded 04

    Swing check forward flow 2

    Swing check backward flow infinity Tees

    Line flow flanged 02

    180deg return bends Line flow threaded 09

    Flanged 02 Branch flow flanged 10

    Threaded 15 Branch flow threaded 20

    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

    Square Connection 05 Square Connection 10

    Rounded Connection 02 Rounded Connection 10

    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

    Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

    entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

    One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

    entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

    P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

    to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

    the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

    and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

    pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

    result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

    be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

    lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

    LMNOLMNOengcom httpwwwlmnoengcom

    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

    bull

    Trapezoidal Open Channel Design Calculation

    Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

    Froude number Manning coefficient channel slope

    To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

    Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

    Register to enable Calculate button

    Your browser does not support Java or Java is disabled in your browser Calculation should be here

    Links on this page Introduction Variables Manning n coefficients Error Messages References

    IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

    beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

    The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

    Variables [] indicates dimensions To calculation

    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

    divided by vertical distance

    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

    Oslash = Angle formed by S

    Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

    Material Manning n Material Manning n

    Natural Streams Excavated Earth Channels

    Clean and Straight 0030 Clean 0022

    Major Rivers 0035 Gravelly 0025

    Sluggish with Deep Pools 0040 Weedy 0030

    Stony Cobbles 0035

    Metals Floodplains

    Brass 0011 Pasture Farmland 0035

    Cast Iron 0013 Light Brush 0050

    Smooth Steel 0012 Heavy Brush 0075

    Corrugated Metal 0022 Trees 015

    Non-Metals

    Glass 0010 Finished Concrete 0012

    Clay Tile 0014 Unfinished Concrete 0014

    Brickwork 0015 Gravel 0029

    Asphalt 0016 Earth 0025

    Masonry 0025 Planed Wood 0012

    Unplaned Wood 0013

    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

    Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

    The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

    cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

    simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

    The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

    References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

    a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

    Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

    French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

    Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

    7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

    Waterhammer surge analysis and transient analysis pipe flow modeling software

    Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

    View the version 40 New Features List

    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

    Waterhammer surge analysis and transient analysis pipe flow modeling software

    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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    copy 2001-2007 Applied Flow Technology All Rights Reserved

    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
      • Local Disk
        • Circular Culvert Design Calculations Software Equations
            • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
              • Local Disk
                • Culvert Design Inlet and Outlet Control
                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                      • Local Disk
                        • Design of Circular Water Pipes using Hazen Williams Equation
                            • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                              • Local Disk
                                • DPlot Graphing Software for Scientists and Engineers - Home Page
                                    • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                      • Local Disk
                                        • Gradually Varied Flow Calculation Backwater profile
                                            • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                • Hydraulic Jump Calculation
                                                    • file____E__engineering_hydraulics_Manning20Equationpdf
                                                      • Local Disk
                                                        • Manning Equation
                                                            • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                              • Local Disk
                                                                • Non-Circular Open Channel Geometry
                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                      • Local Disk
                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                              • Local Disk
                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                    • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                      • Local Disk
                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                            • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                              • Local Disk
                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                      • Local Disk
                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

      Circular Culvert Design Calculations Software Equations

      are inconsistentn = Manning coefficient n is a function of the culvert material such as plastic concrete brick etc Values for n can be found in the table below of Mannings n coefficientsP = Wetted perimeter [L] P is the contact length (in the cross-section) between the water and the culvertQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the culvert [L] If the culvert has a small slope (S) then entering the vertical depth introduces only minimal errorOslash = Angle representing how full the culvert is [radians] A culvert with Oslash=0 radians (0o) contains no water a culvert with Oslash=pi radians (180o) is half full and a culvert with Oslash=2 pi radians (360o) is completely full

      Mannings n Coefficients To top of page The table shows the Manning n values for materials most commonly used for culverts These values were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references) A more complete table of Manning n values can be found on our Manning n page

      Material Manning n Material Manning n

      Metals

      Brass 0011 Smooth Steel 0012

      Cast Iron 0013 Corrugated Metal 0022

      Non-Metals

      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

      Glass 0010 Finished Concrete 0012

      Clay Tile 0014 Unfinished Concrete 0014

      Brickwork 0015 Gravel 0029

      Asphalt 0016 Earth 0025

      Masonry 0025 Planed Wood 0012

      Unplaned Wood 0013

      fileE|engineeringhydraulicsCircular20Culvert2sign20Calculations20-20Software20-20Equationshtm (3 of 4)12112007 40251 PM

      Circular Culvert Design Calculations Software Equations

      Error Messages To top of page Infeasible Input Td gt 1 Water top width cannot be greater than the culvert diameterAn input is lt= 0 Certain inputs must be positiveInfeasible Input T lt 0 Water top width cannot be negativeInfeasible Input yd gt 1 Water depth cannot exceed the pipe diameter

      References (footnotes refer back to Manning n table) To top of page a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

      Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc

      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

      copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)Revision 0 on 12171998 Revision 1 on 7132000 (additional units)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsCircular20Culvert2sign20Calculations20-20Software20-20Equationshtm (4 of 4)12112007 40251 PM

      Culvert Design Inlet and Outlet Control

      bull

      Culvert DesignInlet and Outlet Control

      Flow thru culverts and over road or damGraph Headwater depth vs Flow

      Based on HDS-5 methodology

      To LMNO Engineering home page Circular Culvert using Manning Equation LMNOLMNOengcom Unit Conversions Register Trouble printing

      Diagram of Flow through a Culvert

      Register to fully enable Calculate buttonDemonstration mode for 09 m lt D lt 11 m and Nlt3 (D is pipe diameter N is number of pipes)

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      Links on this page Introduction Equations Variables Values of Coefficients and Manning n Error Messages and Validity References

      In the calculation abovemiddot Culvert Types Conc Sq edge Wall = Concrete pipe with square edged inlet and headwall Conc Groove Wall = Concrete pipe with groove end at inlet and headwall Conc Groove Proj = Concrete pipe with groove end projecting at inlet

      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (1 of 7)12112007 40331 PM

      Culvert Design Inlet and Outlet Control

      CMP Headwall = Corrugated metal pipe with headwall at inlet CMP Mitered = Corrugated metal pipe mitered to slope at inlet CMP Projecting = Corrugated metal pipe projecting at inlet

      middot Unitsm=meters ft=feet ls=litersec cfm=cubic feet per minute cfs=cubic feet per second gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day MGD=Millions of US gallons per day

      middot You can enter tailwater depth (Yt) as a negative number if flow from the culvert drops down to a receiving channel You dont

      need to know the exact elevation drop entering any negative number for Yt will have the same effect

      middot The phrase Inlet Control or Outlet Control that appears in the upper right hand corner of the calculation refers to the type of control for the total flow (Qt) entered in the calculations upper left hand corner The graph below the calculation plots headwater

      depth (Yh) for the range of Qt min to Qt max entered in the bottom right hand corner The type of control may change from one part

      of the graph to another as Qt changes

      Introduction Culverts have been utilized for thousands of years as a means to transmit water under walkways or roads Often a culvert is simply installed without much thought to how much water it needs to convey under extreme conditions If a culvert cannot convey all of the incoming water then the water will flow over or around the pipe or simply back up behind the culvert creating a pond or reservoir If any of these conditions are unacceptable then the proper culvert diameter and number of culverts must be selected prior to installation in order to convey all of the anticipated water through the pipe(s) This calculation helps the designer size culverts as well as present a headwater depth vs discharge rating curve

      The LMNO Engineering calculation is primarily based on the methodology presented in Hydraulic Design of Highway Culverts by Normann (1985) and published by the US Department of Transportations Federal Highway Administration It is also known as HDS-5 (Hydraulic Design Series No 5) HDS-5 focuses on culvert design Culvert design is usually based on the maximum acceptable discharge - thus the HDS-5 methodology is geared toward culverts flowing full with water possibly flowing over the road above the culvert In addition to programming the HDS-5 methodology LMNO Engineering wished to compute headwater depths for lesser flows Therefore in addition to the HDS-5 methodology we have added the Manning equation for culverts flowing partially full The HDS-5 methodology also assumes that the user knows the tailwater depth (Yt) before using the

      methodology Though Yt can be found by field measurements it is often computed in the office using Mannings equation based on

      bottom width side slopes channel roughness and channel slope Therefore LMNO Engineering added the additional feature of a built-in subroutine for computing Yt for trapezoidal channels Note that for the graphing portion of our calculation Yt is re-

      computed for the entire range of flows (Qt) shown on the graph (unless the user specifically inputs Yt)

      As explained in Normann 1985 (also known as HDS-5) the discharge through a culvert is controlled by either inlet or outlet conditions Inlet control means that flow through the culvert is limited by culvert entrance characteristics Outlet control means that flow through the culvert is limited by friction between the flowing water and the culvert barrel The term outlet control is a bit of a misnomer because friction along the entire length of the culvert is as important as the actual outlet condition (the tailwater depth) Inlet control most often occurs for short smooth or greatly downward sloping culverts Outlet control governs for long rough or slightly sloping culverts The type of control also depends on the flowrate For a given culvert installation inlet control may govern for a certain range of flows while outlet control may govern for other flowrates If the flowrate is large enough water could go over the road (or dam) In this case the calculation automatically computes the amount of water going over the road and through each culvert as well as the headwater depth

      If you have surfed around our website you may have noticed our other calculations for circular culverts We have a calculation using Mannings equation for design of circular culverts Since it uses Mannings equation it assumes the culvert is long enough so that normal depth is achieved We also have a calculation for computing discharge from the exit depth (end depth) in a circular culvert - very useful for flowrate measurement in the field For flows under pressure we have several calculations listed under the Pipe Flow category on our home page

      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (2 of 7)12112007 40331 PM

      Culvert Design Inlet and Outlet Control

      Equations and Methodology Back to calculationThe LMNO Engineering methodology generally follows that of Normann (1985 also known as HDS-5) However the Normann methodology is mainly for culvert design Culvert design usually involves the largest expected flowrate We wanted to write a calculation that also determines headwater depth for small flowrates Therefore in addition to the Normann methodology we have incorporated Mannings equation for outlet control when the headwater depth is less than 093 times the culvert diameter 093D is used since it is the depth at which discharge through a partially full culvert is a maximum (Chow 1959) At depths greater than 093D and for full flow the Nomann (1985) equation is used for outlet control For inlet control our calculation uses Normanns equations

      Many of the equations shown below are empirical and require US Customary units (feet seconds and radians) Some of the equations are based on first principles and are compatible with any consistent set of units (eg SI) However to keep this web page from being too busy we have refrained from indicating which equations are empirical and which are fundamental If you work through the equations by hand please use feet seconds and radians in all of them to avoid any problem with units [Our calculation (above) allows many different types of units the units are internally converted before and after using the equations]

      Since total flowrate (Qt) is entered and headwater depth (Yh) is computed the equations below are solved simultaneously to

      determine Yh Outlet versus inlet control is determined by the equation resulting in a larger value for Yh

      All of the variables are defined below in the Variables section Pipe downstream invert elevation is defined as 00

      General EquationsQt = Qr + N Qp Sp = Sc - Yf Lp Ei = Lp Sp Eh = Ei + Yh V=Qp Av

      Tailwater Depth Yt

      Yt can be computed or input If it is computed Mannings equation is used (Chow 1959)

      Since Qt is input the above equations are solved numerically (backwards) for Yt

      Headwater depth Yh

      Yh is computed independently based on inlet and outlet control equations The equation that gives the larger value of Yh is

      considered to be the controlling mechanism and is reported

      Inlet Control (see below for values of constants C1 C2 C3 C4 C5)

      Outlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests computing Yv using the

      Manning equation If Yv is greater than D then Yv is set to D

      Unsubmerged Inlet (Normann 1985)

      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (3 of 7)12112007 40331 PM

      Culvert Design Inlet and Outlet Control

      Submerged Inlet (Normann 1985)

      Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

      YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

      If Yhlt093D then Mannings equation (Chow 1959) is used

      Since Qp is input the above equations are solved numerically for Yt

      If Yhgt=093D Normann (1985) is used

      Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (4 of 7)12112007 40331 PM

      Culvert Design Inlet and Outlet Control

      Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

      Variables Back to calculation

      A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

      Av=Flow area in one pipe used for computing outlet velocity [ft2]

      b=Width of channel bottom [ft] Used for computing Yt

      C1 C2 C3 C4 C5=Constants for inlet control equations See values below

      D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

      Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

      Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

      g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

      Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

      (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

      the roadnc=Channel Manning n coefficient See values below

      np=Pipe (culvert) Manning n coefficient See values below

      N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

      Qr=Flowrate over the road (or dam) [cfs]

      Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

      Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

      Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

      Tc=Top width of flow in one pipe based on critical depth [ft]

      V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

      Yavg=Average water depth [ft]

      Yc=Critical water depth [ft]

      Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

      Yh=Headwater depth [ft]

      Yo=Water outlet depth [ft]

      Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

      Yv=Depth used for computing outlet velocity [ft]

      z1=Left side slope of existing natural channel [horizontalvertical]

      z2=Right side slope of existing natural channel [horizontalvertical]

      Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

      Ke are from Normann (1985)

      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (5 of 7)12112007 40331 PM

      Culvert Design Inlet and Outlet Control

      Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

      Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

      Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

      Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

      Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

      Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

      Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

      Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

      Clean and Straight 0030 Clean 0022

      Major Rivers 0035 Gravelly 0025

      Sluggish with Deep Pools 0040 Weedy 0030

      Stony Cobbles 0035

      Floodplains

      Pasture Farmland 0035 Heavy Brush 0075

      Light Brush 0050 Trees 015

      Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

      Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

      Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

      the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

      Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

      discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

      side slopesNeed Scgt0 Channel cannot be horizontal

      Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

      is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

      Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

      Culvert Design Inlet and Outlet Control

      Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

      Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

      Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

      minimum and maximum are too close together to have good axis labels for the graph

      Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

      YtgtEr since the equations are only valid for Ytlt=Er

      References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

      French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

      Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

      Design of Circular Water Pipes using Hazen Williams Equation

      bull

      Design of Circular Pressurized Water Pipes

      Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

      ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

      Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

      LMNO Engineering home page Unit Conversions Page Trouble printing

      Register to enable Calculate button

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

      Piping Scenarios

      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

      Design of Circular Water Pipes using Hazen Williams Equation

      Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

      Design of Circular Water Pipes using Hazen Williams Equation

      Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

      Steady State Energy Equation used for this page Back to CalculationsObtained from References

      Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

      k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

      Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

      Design of Circular Water Pipes using Hazen Williams Equation

      Material C Material C

      Asbestos Cement 140 Copper 130-140

      Brass 130-140 Galvanized iron 120

      Brick sewer 100 Glass 140

      Cast-Iron Lead 130-140

      New unlined 130 Plastic 140-150

      10 yr old 107-113 Steel

      20 yr old 89-100 Coal-tar enamel lined 145-150

      30 yr old 75-90 New unlined 140-150

      40 yr old 64-83 Riveted 110

      ConcreteConcrete-lined

      Steel forms 140 Tin 130

      Wooden forms 120 Vitrif clay (good condition) 110-140

      Centrifugally spun 135 Wood stave (avg condition) 120

      Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

      Fitting Km Fitting Km

      Valves Elbows

      Globe fully open 10 Regular 90deg flanged 03

      Angle fully open 2 Regular 90deg threaded 15

      Gate fully open 015 Long radius 90deg flanged 02

      Gate 14 closed 026 Long radius 90deg threaded 07

      Gate 12 closed 21 Long radius 45deg threaded 02

      Gate 34 closed 17 Regular 45deg threaded 04

      Swing check forward flow 2

      Swing check backward flow infinity Tees

      Line flow flanged 02

      180deg return bends Line flow threaded 09

      Flanged 02 Branch flow flanged 10

      Threaded 15 Branch flow threaded 20

      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

      Design of Circular Water Pipes using Hazen Williams Equation

      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

      Square Connection 05 Square Connection 10

      Rounded Connection 02 Rounded Connection 10

      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

      copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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      The most recent update includes 2D vector plots and the ability to draw antialiased curves and other graphic objects for more attractive graphs

      Other ProductsIf you produce graphs with DPlot and would like to distribute them to others youll want to take a look at DPlot Viewer This is a free application that may be distributed to others without charge DPlot Viewer will display andor print any graph produced by DPlot

      Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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      DPlot Graphing Software for Scientists and Engineers - Home Page

      or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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      Gradually Varied Flow Calculation Backwater profile

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      Gradually Varied Flow in Trapezoidal Channel

      Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

      Compute normal and critical depths

      To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

      LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

      Cross-Section of Trapezoidal Channel

      Gradually Varied Flow Profiles

      CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

      middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

      Gradually Varied Flow Calculation Backwater profile

      Links on this page Equations Variables Manning n coefficients Error messages References

      Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

      equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

      calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

      The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

      Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

      using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

      References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

      empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

      Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

      Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

      1985) along with the fundamental equations above to solve for Yc

      Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

      the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

      Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

      critical (C) The slopes are further classified by a number (1 2 or 3) as follows

      For mild slopes (YngtYc)

      If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

      water depth gets closer to Yn as the calculation proceeds further and further upstream

      If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

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      Gradually Varied Flow Calculation Backwater profile

      The water depth gets closer to Yn as the calculation proceeds further and further upstream

      If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

      is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

      For steep slopes (YcgtYn)

      If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

      is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

      If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

      water depth gets closer to Yn as the calculation proceeds further and further downstream

      If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

      water depth gets closer to Yn as the calculation proceeds further and further downstream

      For critical slopes (Yc=Yn)

      If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

      water depth gets closer to Yn as the calculation proceeds further and further upstream

      If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

      water depth gets closer to Yn as the calculation proceeds further and further downstream

      There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

      Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

      At control section i=1 and Yi=Ys

      Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

      Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

      Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

      P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

      differential depth increments (this is the basis of the Improved Euler method)

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      Gradually Varied Flow Calculation Backwater profile

      Then repeat the loop by incrementing i

      The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

      Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

      Ap=Area at Xp [m2]

      A2=Area for intermediate computation in Improved Euler method [m2]

      dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

      (dYdX)2=Second depth increment for Improved Euler method [m]

      B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

      Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

      Epy=Elevation of water surface at Xp [m]

      F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

      g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

      P2=Second wetted perimeter computed in Improved Euler method [m]

      Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

      Sf1=First energy slope for Improved Euler method [dimensionless]

      Sf2=Second energy slope for Improved Euler method [dimensionless]

      T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

      T2=Second top width computed in Improved Euler method [m]

      Tp=Top width at Xp [m]

      V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

      X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

      is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

      Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

      automatically set Xp to Xmax

      Y=Water depth [m]Yc=Critical depth [m]

      Yi=Water depth computed at successive i intervals in Improved Euler method [m]

      Yn=Normal depth [m]

      Yp=Depth at Xp [m]

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      Gradually Varied Flow Calculation Backwater profile

      Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

      Y2=Second depth computed in Improved Euler method [m]

      Z1=One channel side slope (horizontal to vertical ratio) [mm]

      Z2=The other channel side slope (horizontal to vertical ratio) [mm]

      Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

      Material Manning n Material Manning n

      Natural Streams Excavated Earth Channels

      Clean and Straight 0030 Clean 0022

      Major Rivers 0035 Gravelly 0025

      Sluggish with Deep Pools 0040 Weedy 0030

      Stony Cobbles 0035

      Metals Floodplains

      Brass 0011 Pasture Farmland 0035

      Cast Iron 0013 Light Brush 0050

      Smooth Steel 0012 Heavy Brush 0075

      Corrugated Metal 0022 Trees 015

      Non-Metals

      Glass 0010 Finished Concrete 0012

      Clay Tile 0014 Unfinished Concrete 0014

      Brickwork 0015 Gravel 0029

      Asphalt 0016 Earth 0025

      Masonry 0025 Planed Wood 0012

      Unplaned Wood 0013

      Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

      20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

      Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

      Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

      is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

      References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

      Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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      Gradually Varied Flow Calculation Backwater profile

      Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

      French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

      Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

      Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

      Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

      Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

      copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

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      Hydraulic Jump Calculation

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      Hydraulic Jump in Horizontal Rectangular Channel

      Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

      jump length and energy loss

      To LMNO Engineering home page (all calculations) Related open channel calculations

      Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

      Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

      fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

      Hydraulic Jump Calculation

      Register to enable Calculate button

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      Equations

      Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

      V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

      L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

      where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

      Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

      What is a Hydraulic Jump

      A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

      According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

      oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

      occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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      Hydraulic Jump Calculation

      MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

      Need F1 gt1 Upstream flow must be supercritical

      ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

      copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

      Manning Equation

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      Mannings Equation Calculator Software The open channel flow software website

      LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

      Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

      and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

      The product AP is also known as the hydraulic radius Rh

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      Non-Circular Open Channel Geometry

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      Geometric Calculations for Non-Circular Partially Filled Channels

      The open channel flow calculations software website

      Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

      Equations (note that R=AP)

      fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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      Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

      losses

      Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

      pipe Dont have to use all the pipes or nodes

      To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

      Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

      Register to fully enable Calculate button

      Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

      IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

      Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

      The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

      Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

      Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

      1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

      Pipe flows are adjusted iteratively using the following equation

      until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

      Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

      Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

      Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

      where log is base 10 logarithm and ln is natural logarithm Variable definitions

      Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

      Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

      Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

      Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

      The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

      ApplicationsThe pipe network calculation has many applications Two examples will be provided

      1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

      pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

      2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

      Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

      Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

      Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

      A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

      n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

      Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

      Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

      References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

      Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      bull

      Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

      Weisbach - Moody friction losses)

      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

      (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

      Parabolic shaped pump curve is formed from the two points

      ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

      curve Hazen-Williams with pump curve

      Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

      Register to enable Calculate button

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

      IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

      A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

      For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

      (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

      Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

      calculation will look like

      The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

      Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

      Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

      is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

      defined for liquids

      Variables Units F=force L=length P=pressure T=time Back to Calculations

      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

      A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

      hf = Major losses for entire pipe [L] Also known as friction losses

      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

      hm = Minor losses for entire pipe [L]

      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

      K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

      for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

      P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

      location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

      zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

      this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

      v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

      Fitting K Fitting K

      Valves Elbows

      Globe fully open 10 Regular 90deg flanged 03

      Angle fully open 2 Regular 90deg threaded 15

      Gate fully open 015 Long radius 90deg flanged 02

      Gate 14 closed 026 Long radius 90deg threaded 07

      Gate 12 closed 21 Long radius 45deg threaded 02

      Gate 34 closed 17 Regular 45deg threaded 04

      Swing check forward flow 2

      Swing check backward flow infinity Tees

      Line flow flanged 02

      180deg return bends Line flow threaded 09

      Flanged 02 Branch flow flanged 10

      Threaded 15 Branch flow threaded 20

      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      Square Connection 05 Square Connection 10

      Rounded Connection 02 Rounded Connection 10

      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

      Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

      The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

      Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

      the pipe or K for the suction pipe was entered as greater than K for the entire system

      Other messagesK must be gt=1 If Q known Solve for D and V

      3=0 then K must be gt 1 in order to solve

      Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

      reservoirs are defined to be at zero pressure thus zero pressure difference

      Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

      Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

      References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

      Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

      Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

      Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

      Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

      White F M 1979 Fluid Mechanics McGraw-Hill Inc

      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      bull

      Circular Pressurized Water Pipes with Pump Curve

      (Hazen Williams)

      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

      (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

      ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

      curve Darcy-Weisbach with pump curve

      Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

      Register to enable Calculate button

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

      IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

      function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

      manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

      Equations and Methodology Back to Calculations

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

      calculation will look like

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

      Variables Units L=length P=pressure T=time Back to Calculations

      A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

      g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

      hf = Major losses for entire pipe [L]

      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

      hm = Minor losses for entire pipe [L]

      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

      k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

      L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

      program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

      location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

      zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

      this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

      Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

      available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

      and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

      Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

      Material C Material C

      Asbestos Cement 140 Copper 130-140

      Brass 130-140 Galvanized iron 120

      Brick sewer 100 Glass 140

      Cast-Iron Lead 130-140

      New unlined 130 Plastic 140-150

      10 yr old 107-113 Steel

      20 yr old 89-100 Coal-tar enamel lined 145-150

      30 yr old 75-90 New unlined 140-150

      40 yr old 64-83 Riveted 110

      ConcreteConcrete-lined

      Steel forms 140 Tin 130

      Wooden forms 120 Vitrif clay (good condition) 110-140

      Centrifugally spun 135 Wood stave (avg condition) 120

      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

      Fitting K Fitting K

      Valves Elbows

      Globe fully open 10 Regular 90deg flanged 03

      Angle fully open 2 Regular 90deg threaded 15

      Gate fully open 015 Long radius 90deg flanged 02

      Gate 14 closed 026 Long radius 90deg threaded 07

      Gate 12 closed 21 Long radius 45deg threaded 02

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      Gate 34 closed 17 Regular 45deg threaded 04

      Swing check forward flow 2

      Swing check backward flow infinity Tees

      Line flow flanged 02

      180deg return bends Line flow threaded 09

      Flanged 02 Branch flow flanged 10

      Threaded 15 Branch flow threaded 20

      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

      Square Connection 05 Square Connection 10

      Rounded Connection 02 Rounded Connection 10

      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

      Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

      entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

      One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

      entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

      P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

      to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

      the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

      and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

      pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

      result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

      be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

      lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

      LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

      bull

      Trapezoidal Open Channel Design Calculation

      Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

      Froude number Manning coefficient channel slope

      To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

      Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

      Register to enable Calculate button

      Your browser does not support Java or Java is disabled in your browser Calculation should be here

      Links on this page Introduction Variables Manning n coefficients Error Messages References

      IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

      beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

      The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

      In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

      Variables [] indicates dimensions To calculation

      A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

      divided by vertical distance

      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

      Oslash = Angle formed by S

      Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

      Material Manning n Material Manning n

      Natural Streams Excavated Earth Channels

      Clean and Straight 0030 Clean 0022

      Major Rivers 0035 Gravelly 0025

      Sluggish with Deep Pools 0040 Weedy 0030

      Stony Cobbles 0035

      Metals Floodplains

      Brass 0011 Pasture Farmland 0035

      Cast Iron 0013 Light Brush 0050

      Smooth Steel 0012 Heavy Brush 0075

      Corrugated Metal 0022 Trees 015

      Non-Metals

      Glass 0010 Finished Concrete 0012

      Clay Tile 0014 Unfinished Concrete 0014

      Brickwork 0015 Gravel 0029

      Asphalt 0016 Earth 0025

      Masonry 0025 Planed Wood 0012

      Unplaned Wood 0013

      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

      Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

      The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

      cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

      simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

      The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

      References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

      a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

      Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

      French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

      Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

      7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

      Waterhammer surge analysis and transient analysis pipe flow modeling software

      Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

      Products

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      - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

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      home gt products gt impulse gt overview

      Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

      View the version 40 New Features List

      Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

      AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

      Waterhammer surge analysis and transient analysis pipe flow modeling software

      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

      From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

      View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

      Learn More About AFT Impulse 40

      Details Views Brochure Demo

      copy 2001-2007 Applied Flow Technology All Rights Reserved

      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
        • Local Disk
          • Circular Culvert Design Calculations Software Equations
              • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                • Local Disk
                  • Culvert Design Inlet and Outlet Control
                      • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                        • Local Disk
                          • Design of Circular Water Pipes using Hazen Williams Equation
                              • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                • Local Disk
                                  • DPlot Graphing Software for Scientists and Engineers - Home Page
                                      • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                        • Local Disk
                                          • Gradually Varied Flow Calculation Backwater profile
                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                • Local Disk
                                                  • Hydraulic Jump Calculation
                                                      • file____E__engineering_hydraulics_Manning20Equationpdf
                                                        • Local Disk
                                                          • Manning Equation
                                                              • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                • Local Disk
                                                                  • Non-Circular Open Channel Geometry
                                                                      • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                        • Local Disk
                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                              • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                • Local Disk
                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                      • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                        • Local Disk
                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                              • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                • Local Disk
                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                        • Local Disk
                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

        Circular Culvert Design Calculations Software Equations

        Error Messages To top of page Infeasible Input Td gt 1 Water top width cannot be greater than the culvert diameterAn input is lt= 0 Certain inputs must be positiveInfeasible Input T lt 0 Water top width cannot be negativeInfeasible Input yd gt 1 Water depth cannot exceed the pipe diameter

        References (footnotes refer back to Manning n table) To top of page a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

        Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc

        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

        copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)Revision 0 on 12171998 Revision 1 on 7132000 (additional units)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsCircular20Culvert2sign20Calculations20-20Software20-20Equationshtm (4 of 4)12112007 40251 PM

        Culvert Design Inlet and Outlet Control

        bull

        Culvert DesignInlet and Outlet Control

        Flow thru culverts and over road or damGraph Headwater depth vs Flow

        Based on HDS-5 methodology

        To LMNO Engineering home page Circular Culvert using Manning Equation LMNOLMNOengcom Unit Conversions Register Trouble printing

        Diagram of Flow through a Culvert

        Register to fully enable Calculate buttonDemonstration mode for 09 m lt D lt 11 m and Nlt3 (D is pipe diameter N is number of pipes)

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        Links on this page Introduction Equations Variables Values of Coefficients and Manning n Error Messages and Validity References

        In the calculation abovemiddot Culvert Types Conc Sq edge Wall = Concrete pipe with square edged inlet and headwall Conc Groove Wall = Concrete pipe with groove end at inlet and headwall Conc Groove Proj = Concrete pipe with groove end projecting at inlet

        fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (1 of 7)12112007 40331 PM

        Culvert Design Inlet and Outlet Control

        CMP Headwall = Corrugated metal pipe with headwall at inlet CMP Mitered = Corrugated metal pipe mitered to slope at inlet CMP Projecting = Corrugated metal pipe projecting at inlet

        middot Unitsm=meters ft=feet ls=litersec cfm=cubic feet per minute cfs=cubic feet per second gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day MGD=Millions of US gallons per day

        middot You can enter tailwater depth (Yt) as a negative number if flow from the culvert drops down to a receiving channel You dont

        need to know the exact elevation drop entering any negative number for Yt will have the same effect

        middot The phrase Inlet Control or Outlet Control that appears in the upper right hand corner of the calculation refers to the type of control for the total flow (Qt) entered in the calculations upper left hand corner The graph below the calculation plots headwater

        depth (Yh) for the range of Qt min to Qt max entered in the bottom right hand corner The type of control may change from one part

        of the graph to another as Qt changes

        Introduction Culverts have been utilized for thousands of years as a means to transmit water under walkways or roads Often a culvert is simply installed without much thought to how much water it needs to convey under extreme conditions If a culvert cannot convey all of the incoming water then the water will flow over or around the pipe or simply back up behind the culvert creating a pond or reservoir If any of these conditions are unacceptable then the proper culvert diameter and number of culverts must be selected prior to installation in order to convey all of the anticipated water through the pipe(s) This calculation helps the designer size culverts as well as present a headwater depth vs discharge rating curve

        The LMNO Engineering calculation is primarily based on the methodology presented in Hydraulic Design of Highway Culverts by Normann (1985) and published by the US Department of Transportations Federal Highway Administration It is also known as HDS-5 (Hydraulic Design Series No 5) HDS-5 focuses on culvert design Culvert design is usually based on the maximum acceptable discharge - thus the HDS-5 methodology is geared toward culverts flowing full with water possibly flowing over the road above the culvert In addition to programming the HDS-5 methodology LMNO Engineering wished to compute headwater depths for lesser flows Therefore in addition to the HDS-5 methodology we have added the Manning equation for culverts flowing partially full The HDS-5 methodology also assumes that the user knows the tailwater depth (Yt) before using the

        methodology Though Yt can be found by field measurements it is often computed in the office using Mannings equation based on

        bottom width side slopes channel roughness and channel slope Therefore LMNO Engineering added the additional feature of a built-in subroutine for computing Yt for trapezoidal channels Note that for the graphing portion of our calculation Yt is re-

        computed for the entire range of flows (Qt) shown on the graph (unless the user specifically inputs Yt)

        As explained in Normann 1985 (also known as HDS-5) the discharge through a culvert is controlled by either inlet or outlet conditions Inlet control means that flow through the culvert is limited by culvert entrance characteristics Outlet control means that flow through the culvert is limited by friction between the flowing water and the culvert barrel The term outlet control is a bit of a misnomer because friction along the entire length of the culvert is as important as the actual outlet condition (the tailwater depth) Inlet control most often occurs for short smooth or greatly downward sloping culverts Outlet control governs for long rough or slightly sloping culverts The type of control also depends on the flowrate For a given culvert installation inlet control may govern for a certain range of flows while outlet control may govern for other flowrates If the flowrate is large enough water could go over the road (or dam) In this case the calculation automatically computes the amount of water going over the road and through each culvert as well as the headwater depth

        If you have surfed around our website you may have noticed our other calculations for circular culverts We have a calculation using Mannings equation for design of circular culverts Since it uses Mannings equation it assumes the culvert is long enough so that normal depth is achieved We also have a calculation for computing discharge from the exit depth (end depth) in a circular culvert - very useful for flowrate measurement in the field For flows under pressure we have several calculations listed under the Pipe Flow category on our home page

        fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (2 of 7)12112007 40331 PM

        Culvert Design Inlet and Outlet Control

        Equations and Methodology Back to calculationThe LMNO Engineering methodology generally follows that of Normann (1985 also known as HDS-5) However the Normann methodology is mainly for culvert design Culvert design usually involves the largest expected flowrate We wanted to write a calculation that also determines headwater depth for small flowrates Therefore in addition to the Normann methodology we have incorporated Mannings equation for outlet control when the headwater depth is less than 093 times the culvert diameter 093D is used since it is the depth at which discharge through a partially full culvert is a maximum (Chow 1959) At depths greater than 093D and for full flow the Nomann (1985) equation is used for outlet control For inlet control our calculation uses Normanns equations

        Many of the equations shown below are empirical and require US Customary units (feet seconds and radians) Some of the equations are based on first principles and are compatible with any consistent set of units (eg SI) However to keep this web page from being too busy we have refrained from indicating which equations are empirical and which are fundamental If you work through the equations by hand please use feet seconds and radians in all of them to avoid any problem with units [Our calculation (above) allows many different types of units the units are internally converted before and after using the equations]

        Since total flowrate (Qt) is entered and headwater depth (Yh) is computed the equations below are solved simultaneously to

        determine Yh Outlet versus inlet control is determined by the equation resulting in a larger value for Yh

        All of the variables are defined below in the Variables section Pipe downstream invert elevation is defined as 00

        General EquationsQt = Qr + N Qp Sp = Sc - Yf Lp Ei = Lp Sp Eh = Ei + Yh V=Qp Av

        Tailwater Depth Yt

        Yt can be computed or input If it is computed Mannings equation is used (Chow 1959)

        Since Qt is input the above equations are solved numerically (backwards) for Yt

        Headwater depth Yh

        Yh is computed independently based on inlet and outlet control equations The equation that gives the larger value of Yh is

        considered to be the controlling mechanism and is reported

        Inlet Control (see below for values of constants C1 C2 C3 C4 C5)

        Outlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests computing Yv using the

        Manning equation If Yv is greater than D then Yv is set to D

        Unsubmerged Inlet (Normann 1985)

        fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (3 of 7)12112007 40331 PM

        Culvert Design Inlet and Outlet Control

        Submerged Inlet (Normann 1985)

        Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

        YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

        If Yhlt093D then Mannings equation (Chow 1959) is used

        Since Qp is input the above equations are solved numerically for Yt

        If Yhgt=093D Normann (1985) is used

        Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

        fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (4 of 7)12112007 40331 PM

        Culvert Design Inlet and Outlet Control

        Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

        Variables Back to calculation

        A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

        Av=Flow area in one pipe used for computing outlet velocity [ft2]

        b=Width of channel bottom [ft] Used for computing Yt

        C1 C2 C3 C4 C5=Constants for inlet control equations See values below

        D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

        Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

        Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

        g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

        Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

        (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

        the roadnc=Channel Manning n coefficient See values below

        np=Pipe (culvert) Manning n coefficient See values below

        N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

        Qr=Flowrate over the road (or dam) [cfs]

        Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

        Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

        Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

        Tc=Top width of flow in one pipe based on critical depth [ft]

        V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

        Yavg=Average water depth [ft]

        Yc=Critical water depth [ft]

        Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

        Yh=Headwater depth [ft]

        Yo=Water outlet depth [ft]

        Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

        Yv=Depth used for computing outlet velocity [ft]

        z1=Left side slope of existing natural channel [horizontalvertical]

        z2=Right side slope of existing natural channel [horizontalvertical]

        Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

        Ke are from Normann (1985)

        fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (5 of 7)12112007 40331 PM

        Culvert Design Inlet and Outlet Control

        Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

        Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

        Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

        Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

        Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

        Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

        Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

        Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

        Clean and Straight 0030 Clean 0022

        Major Rivers 0035 Gravelly 0025

        Sluggish with Deep Pools 0040 Weedy 0030

        Stony Cobbles 0035

        Floodplains

        Pasture Farmland 0035 Heavy Brush 0075

        Light Brush 0050 Trees 015

        Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

        Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

        Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

        the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

        Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

        discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

        side slopesNeed Scgt0 Channel cannot be horizontal

        Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

        is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

        Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

        fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

        Culvert Design Inlet and Outlet Control

        Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

        Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

        Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

        minimum and maximum are too close together to have good axis labels for the graph

        Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

        YtgtEr since the equations are only valid for Ytlt=Er

        References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

        French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

        Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

        Design of Circular Water Pipes using Hazen Williams Equation

        bull

        Design of Circular Pressurized Water Pipes

        Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

        ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

        Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

        LMNO Engineering home page Unit Conversions Page Trouble printing

        Register to enable Calculate button

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

        Piping Scenarios

        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

        Design of Circular Water Pipes using Hazen Williams Equation

        Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

        Design of Circular Water Pipes using Hazen Williams Equation

        Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

        Steady State Energy Equation used for this page Back to CalculationsObtained from References

        Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

        k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

        Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

        Design of Circular Water Pipes using Hazen Williams Equation

        Material C Material C

        Asbestos Cement 140 Copper 130-140

        Brass 130-140 Galvanized iron 120

        Brick sewer 100 Glass 140

        Cast-Iron Lead 130-140

        New unlined 130 Plastic 140-150

        10 yr old 107-113 Steel

        20 yr old 89-100 Coal-tar enamel lined 145-150

        30 yr old 75-90 New unlined 140-150

        40 yr old 64-83 Riveted 110

        ConcreteConcrete-lined

        Steel forms 140 Tin 130

        Wooden forms 120 Vitrif clay (good condition) 110-140

        Centrifugally spun 135 Wood stave (avg condition) 120

        Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

        Fitting Km Fitting Km

        Valves Elbows

        Globe fully open 10 Regular 90deg flanged 03

        Angle fully open 2 Regular 90deg threaded 15

        Gate fully open 015 Long radius 90deg flanged 02

        Gate 14 closed 026 Long radius 90deg threaded 07

        Gate 12 closed 21 Long radius 45deg threaded 02

        Gate 34 closed 17 Regular 45deg threaded 04

        Swing check forward flow 2

        Swing check backward flow infinity Tees

        Line flow flanged 02

        180deg return bends Line flow threaded 09

        Flanged 02 Branch flow flanged 10

        Threaded 15 Branch flow threaded 20

        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

        Design of Circular Water Pipes using Hazen Williams Equation

        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

        Square Connection 05 Square Connection 10

        Rounded Connection 02 Rounded Connection 10

        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

        copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

        GRAPH SOFTWARE FOR SCIENTISTS amp ENGINEERS

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        DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

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        DPlot Graphing Software for Scientists and Engineers - Home Page

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        NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

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        Other ProductsIf you produce graphs with DPlot and would like to distribute them to others youll want to take a look at DPlot Viewer This is a free application that may be distributed to others without charge DPlot Viewer will display andor print any graph produced by DPlot

        Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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        DPlot Graphing Software for Scientists and Engineers - Home Page

        or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

        DPlot AccessoriesDo you need a new coffee cup mouse pad or golf shirt Of course you do Visit our online Accessories Store today

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        Gradually Varied Flow Calculation Backwater profile

        bull

        Gradually Varied Flow in Trapezoidal Channel

        Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

        Compute normal and critical depths

        To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

        LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

        Cross-Section of Trapezoidal Channel

        Gradually Varied Flow Profiles

        CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

        middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

        Gradually Varied Flow Calculation Backwater profile

        Links on this page Equations Variables Manning n coefficients Error messages References

        Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

        equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

        calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

        The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

        Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

        using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

        References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

        empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

        Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

        Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

        1985) along with the fundamental equations above to solve for Yc

        Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

        the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

        Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

        critical (C) The slopes are further classified by a number (1 2 or 3) as follows

        For mild slopes (YngtYc)

        If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

        water depth gets closer to Yn as the calculation proceeds further and further upstream

        If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

        Gradually Varied Flow Calculation Backwater profile

        The water depth gets closer to Yn as the calculation proceeds further and further upstream

        If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

        is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

        For steep slopes (YcgtYn)

        If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

        is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

        If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

        water depth gets closer to Yn as the calculation proceeds further and further downstream

        If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

        water depth gets closer to Yn as the calculation proceeds further and further downstream

        For critical slopes (Yc=Yn)

        If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

        water depth gets closer to Yn as the calculation proceeds further and further upstream

        If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

        water depth gets closer to Yn as the calculation proceeds further and further downstream

        There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

        Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

        At control section i=1 and Yi=Ys

        Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

        Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

        Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

        P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

        differential depth increments (this is the basis of the Improved Euler method)

        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

        Gradually Varied Flow Calculation Backwater profile

        Then repeat the loop by incrementing i

        The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

        Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

        Ap=Area at Xp [m2]

        A2=Area for intermediate computation in Improved Euler method [m2]

        dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

        (dYdX)2=Second depth increment for Improved Euler method [m]

        B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

        Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

        Epy=Elevation of water surface at Xp [m]

        F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

        g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

        P2=Second wetted perimeter computed in Improved Euler method [m]

        Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

        Sf1=First energy slope for Improved Euler method [dimensionless]

        Sf2=Second energy slope for Improved Euler method [dimensionless]

        T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

        T2=Second top width computed in Improved Euler method [m]

        Tp=Top width at Xp [m]

        V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

        X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

        is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

        Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

        automatically set Xp to Xmax

        Y=Water depth [m]Yc=Critical depth [m]

        Yi=Water depth computed at successive i intervals in Improved Euler method [m]

        Yn=Normal depth [m]

        Yp=Depth at Xp [m]

        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

        Gradually Varied Flow Calculation Backwater profile

        Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

        Y2=Second depth computed in Improved Euler method [m]

        Z1=One channel side slope (horizontal to vertical ratio) [mm]

        Z2=The other channel side slope (horizontal to vertical ratio) [mm]

        Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

        Material Manning n Material Manning n

        Natural Streams Excavated Earth Channels

        Clean and Straight 0030 Clean 0022

        Major Rivers 0035 Gravelly 0025

        Sluggish with Deep Pools 0040 Weedy 0030

        Stony Cobbles 0035

        Metals Floodplains

        Brass 0011 Pasture Farmland 0035

        Cast Iron 0013 Light Brush 0050

        Smooth Steel 0012 Heavy Brush 0075

        Corrugated Metal 0022 Trees 015

        Non-Metals

        Glass 0010 Finished Concrete 0012

        Clay Tile 0014 Unfinished Concrete 0014

        Brickwork 0015 Gravel 0029

        Asphalt 0016 Earth 0025

        Masonry 0025 Planed Wood 0012

        Unplaned Wood 0013

        Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

        20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

        Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

        Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

        is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

        References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

        Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

        Gradually Varied Flow Calculation Backwater profile

        Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

        French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

        Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

        Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

        Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

        Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

        copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

        Hydraulic Jump Calculation

        bull

        Hydraulic Jump in Horizontal Rectangular Channel

        Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

        jump length and energy loss

        To LMNO Engineering home page (all calculations) Related open channel calculations

        Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

        Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

        Hydraulic Jump Calculation

        Register to enable Calculate button

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        Equations

        Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

        V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

        L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

        where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

        Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

        What is a Hydraulic Jump

        A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

        According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

        oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

        occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

        Hydraulic Jump Calculation

        MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

        Need F1 gt1 Upstream flow must be supercritical

        ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

        copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

        Manning Equation

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        Mannings Equation Calculator Software The open channel flow software website

        LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

        Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

        and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

        The product AP is also known as the hydraulic radius Rh

        fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

        Non-Circular Open Channel Geometry

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        Geometric Calculations for Non-Circular Partially Filled Channels

        The open channel flow calculations software website

        Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

        Equations (note that R=AP)

        fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

        bull

        Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

        losses

        Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

        pipe Dont have to use all the pipes or nodes

        To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

        Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

        Register to fully enable Calculate button

        Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

        IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

        Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

        The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

        Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

        Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

        1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

        Pipe flows are adjusted iteratively using the following equation

        until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

        Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

        Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

        Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

        where log is base 10 logarithm and ln is natural logarithm Variable definitions

        Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

        Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

        Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

        Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

        The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

        ApplicationsThe pipe network calculation has many applications Two examples will be provided

        1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

        pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

        2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

        Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

        Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

        Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

        A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

        n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

        Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

        Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

        References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

        Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        bull

        Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

        Weisbach - Moody friction losses)

        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

        (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

        Parabolic shaped pump curve is formed from the two points

        ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

        curve Hazen-Williams with pump curve

        Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

        Register to enable Calculate button

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

        IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

        A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

        For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

        (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

        Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

        calculation will look like

        The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

        Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

        Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

        is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

        defined for liquids

        Variables Units F=force L=length P=pressure T=time Back to Calculations

        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

        A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

        hf = Major losses for entire pipe [L] Also known as friction losses

        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

        hm = Minor losses for entire pipe [L]

        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

        K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

        for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

        P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

        location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

        zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

        this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

        v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

        Fitting K Fitting K

        Valves Elbows

        Globe fully open 10 Regular 90deg flanged 03

        Angle fully open 2 Regular 90deg threaded 15

        Gate fully open 015 Long radius 90deg flanged 02

        Gate 14 closed 026 Long radius 90deg threaded 07

        Gate 12 closed 21 Long radius 45deg threaded 02

        Gate 34 closed 17 Regular 45deg threaded 04

        Swing check forward flow 2

        Swing check backward flow infinity Tees

        Line flow flanged 02

        180deg return bends Line flow threaded 09

        Flanged 02 Branch flow flanged 10

        Threaded 15 Branch flow threaded 20

        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        Square Connection 05 Square Connection 10

        Rounded Connection 02 Rounded Connection 10

        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

        Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

        The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

        Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

        the pipe or K for the suction pipe was entered as greater than K for the entire system

        Other messagesK must be gt=1 If Q known Solve for D and V

        3=0 then K must be gt 1 in order to solve

        Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

        reservoirs are defined to be at zero pressure thus zero pressure difference

        Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

        Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

        References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

        Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

        Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

        Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

        Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

        White F M 1979 Fluid Mechanics McGraw-Hill Inc

        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        bull

        Circular Pressurized Water Pipes with Pump Curve

        (Hazen Williams)

        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

        (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

        ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

        curve Darcy-Weisbach with pump curve

        Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

        Register to enable Calculate button

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

        IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

        function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

        manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

        Equations and Methodology Back to Calculations

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

        calculation will look like

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

        Variables Units L=length P=pressure T=time Back to Calculations

        A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

        g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

        hf = Major losses for entire pipe [L]

        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

        hm = Minor losses for entire pipe [L]

        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

        k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

        L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

        program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

        location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

        zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

        this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

        Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

        available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

        and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

        Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

        Material C Material C

        Asbestos Cement 140 Copper 130-140

        Brass 130-140 Galvanized iron 120

        Brick sewer 100 Glass 140

        Cast-Iron Lead 130-140

        New unlined 130 Plastic 140-150

        10 yr old 107-113 Steel

        20 yr old 89-100 Coal-tar enamel lined 145-150

        30 yr old 75-90 New unlined 140-150

        40 yr old 64-83 Riveted 110

        ConcreteConcrete-lined

        Steel forms 140 Tin 130

        Wooden forms 120 Vitrif clay (good condition) 110-140

        Centrifugally spun 135 Wood stave (avg condition) 120

        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

        Fitting K Fitting K

        Valves Elbows

        Globe fully open 10 Regular 90deg flanged 03

        Angle fully open 2 Regular 90deg threaded 15

        Gate fully open 015 Long radius 90deg flanged 02

        Gate 14 closed 026 Long radius 90deg threaded 07

        Gate 12 closed 21 Long radius 45deg threaded 02

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        Gate 34 closed 17 Regular 45deg threaded 04

        Swing check forward flow 2

        Swing check backward flow infinity Tees

        Line flow flanged 02

        180deg return bends Line flow threaded 09

        Flanged 02 Branch flow flanged 10

        Threaded 15 Branch flow threaded 20

        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

        Square Connection 05 Square Connection 10

        Rounded Connection 02 Rounded Connection 10

        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

        Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

        entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

        One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

        entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

        P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

        to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

        the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

        and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

        pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

        result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

        be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

        lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

        LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

        bull

        Trapezoidal Open Channel Design Calculation

        Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

        Froude number Manning coefficient channel slope

        To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

        Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

        Register to enable Calculate button

        Your browser does not support Java or Java is disabled in your browser Calculation should be here

        Links on this page Introduction Variables Manning n coefficients Error Messages References

        IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

        beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

        The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

        In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

        Variables [] indicates dimensions To calculation

        A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

        divided by vertical distance

        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

        Oslash = Angle formed by S

        Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

        Material Manning n Material Manning n

        Natural Streams Excavated Earth Channels

        Clean and Straight 0030 Clean 0022

        Major Rivers 0035 Gravelly 0025

        Sluggish with Deep Pools 0040 Weedy 0030

        Stony Cobbles 0035

        Metals Floodplains

        Brass 0011 Pasture Farmland 0035

        Cast Iron 0013 Light Brush 0050

        Smooth Steel 0012 Heavy Brush 0075

        Corrugated Metal 0022 Trees 015

        Non-Metals

        Glass 0010 Finished Concrete 0012

        Clay Tile 0014 Unfinished Concrete 0014

        Brickwork 0015 Gravel 0029

        Asphalt 0016 Earth 0025

        Masonry 0025 Planed Wood 0012

        Unplaned Wood 0013

        Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

        Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

        Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

        Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

        The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

        cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

        simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

        The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

        References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

        a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

        Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

        French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

        Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

        7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

        Waterhammer surge analysis and transient analysis pipe flow modeling software

        Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

        Products

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        home gt products gt impulse gt overview

        Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

        View the version 40 New Features List

        Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

        AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

        Waterhammer surge analysis and transient analysis pipe flow modeling software

        components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

        From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

        View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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        Details Views Brochure Demo

        copy 2001-2007 Applied Flow Technology All Rights Reserved

        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

        • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
          • Local Disk
            • Circular Culvert Design Calculations Software Equations
                • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                  • Local Disk
                    • Culvert Design Inlet and Outlet Control
                        • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                          • Local Disk
                            • Design of Circular Water Pipes using Hazen Williams Equation
                                • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                  • Local Disk
                                    • DPlot Graphing Software for Scientists and Engineers - Home Page
                                        • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                          • Local Disk
                                            • Gradually Varied Flow Calculation Backwater profile
                                                • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                  • Local Disk
                                                    • Hydraulic Jump Calculation
                                                        • file____E__engineering_hydraulics_Manning20Equationpdf
                                                          • Local Disk
                                                            • Manning Equation
                                                                • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                  • Local Disk
                                                                    • Non-Circular Open Channel Geometry
                                                                        • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                          • Local Disk
                                                                            • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                  • Local Disk
                                                                                    • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                        • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                          • Local Disk
                                                                                            • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                  • Local Disk
                                                                                                    • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                        • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                          • Local Disk
                                                                                                            • Waterhammer surge analysis and transient analysis pipe flow modeling software

          Culvert Design Inlet and Outlet Control

          bull

          Culvert DesignInlet and Outlet Control

          Flow thru culverts and over road or damGraph Headwater depth vs Flow

          Based on HDS-5 methodology

          To LMNO Engineering home page Circular Culvert using Manning Equation LMNOLMNOengcom Unit Conversions Register Trouble printing

          Diagram of Flow through a Culvert

          Register to fully enable Calculate buttonDemonstration mode for 09 m lt D lt 11 m and Nlt3 (D is pipe diameter N is number of pipes)

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          Links on this page Introduction Equations Variables Values of Coefficients and Manning n Error Messages and Validity References

          In the calculation abovemiddot Culvert Types Conc Sq edge Wall = Concrete pipe with square edged inlet and headwall Conc Groove Wall = Concrete pipe with groove end at inlet and headwall Conc Groove Proj = Concrete pipe with groove end projecting at inlet

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          Culvert Design Inlet and Outlet Control

          CMP Headwall = Corrugated metal pipe with headwall at inlet CMP Mitered = Corrugated metal pipe mitered to slope at inlet CMP Projecting = Corrugated metal pipe projecting at inlet

          middot Unitsm=meters ft=feet ls=litersec cfm=cubic feet per minute cfs=cubic feet per second gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day MGD=Millions of US gallons per day

          middot You can enter tailwater depth (Yt) as a negative number if flow from the culvert drops down to a receiving channel You dont

          need to know the exact elevation drop entering any negative number for Yt will have the same effect

          middot The phrase Inlet Control or Outlet Control that appears in the upper right hand corner of the calculation refers to the type of control for the total flow (Qt) entered in the calculations upper left hand corner The graph below the calculation plots headwater

          depth (Yh) for the range of Qt min to Qt max entered in the bottom right hand corner The type of control may change from one part

          of the graph to another as Qt changes

          Introduction Culverts have been utilized for thousands of years as a means to transmit water under walkways or roads Often a culvert is simply installed without much thought to how much water it needs to convey under extreme conditions If a culvert cannot convey all of the incoming water then the water will flow over or around the pipe or simply back up behind the culvert creating a pond or reservoir If any of these conditions are unacceptable then the proper culvert diameter and number of culverts must be selected prior to installation in order to convey all of the anticipated water through the pipe(s) This calculation helps the designer size culverts as well as present a headwater depth vs discharge rating curve

          The LMNO Engineering calculation is primarily based on the methodology presented in Hydraulic Design of Highway Culverts by Normann (1985) and published by the US Department of Transportations Federal Highway Administration It is also known as HDS-5 (Hydraulic Design Series No 5) HDS-5 focuses on culvert design Culvert design is usually based on the maximum acceptable discharge - thus the HDS-5 methodology is geared toward culverts flowing full with water possibly flowing over the road above the culvert In addition to programming the HDS-5 methodology LMNO Engineering wished to compute headwater depths for lesser flows Therefore in addition to the HDS-5 methodology we have added the Manning equation for culverts flowing partially full The HDS-5 methodology also assumes that the user knows the tailwater depth (Yt) before using the

          methodology Though Yt can be found by field measurements it is often computed in the office using Mannings equation based on

          bottom width side slopes channel roughness and channel slope Therefore LMNO Engineering added the additional feature of a built-in subroutine for computing Yt for trapezoidal channels Note that for the graphing portion of our calculation Yt is re-

          computed for the entire range of flows (Qt) shown on the graph (unless the user specifically inputs Yt)

          As explained in Normann 1985 (also known as HDS-5) the discharge through a culvert is controlled by either inlet or outlet conditions Inlet control means that flow through the culvert is limited by culvert entrance characteristics Outlet control means that flow through the culvert is limited by friction between the flowing water and the culvert barrel The term outlet control is a bit of a misnomer because friction along the entire length of the culvert is as important as the actual outlet condition (the tailwater depth) Inlet control most often occurs for short smooth or greatly downward sloping culverts Outlet control governs for long rough or slightly sloping culverts The type of control also depends on the flowrate For a given culvert installation inlet control may govern for a certain range of flows while outlet control may govern for other flowrates If the flowrate is large enough water could go over the road (or dam) In this case the calculation automatically computes the amount of water going over the road and through each culvert as well as the headwater depth

          If you have surfed around our website you may have noticed our other calculations for circular culverts We have a calculation using Mannings equation for design of circular culverts Since it uses Mannings equation it assumes the culvert is long enough so that normal depth is achieved We also have a calculation for computing discharge from the exit depth (end depth) in a circular culvert - very useful for flowrate measurement in the field For flows under pressure we have several calculations listed under the Pipe Flow category on our home page

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          Culvert Design Inlet and Outlet Control

          Equations and Methodology Back to calculationThe LMNO Engineering methodology generally follows that of Normann (1985 also known as HDS-5) However the Normann methodology is mainly for culvert design Culvert design usually involves the largest expected flowrate We wanted to write a calculation that also determines headwater depth for small flowrates Therefore in addition to the Normann methodology we have incorporated Mannings equation for outlet control when the headwater depth is less than 093 times the culvert diameter 093D is used since it is the depth at which discharge through a partially full culvert is a maximum (Chow 1959) At depths greater than 093D and for full flow the Nomann (1985) equation is used for outlet control For inlet control our calculation uses Normanns equations

          Many of the equations shown below are empirical and require US Customary units (feet seconds and radians) Some of the equations are based on first principles and are compatible with any consistent set of units (eg SI) However to keep this web page from being too busy we have refrained from indicating which equations are empirical and which are fundamental If you work through the equations by hand please use feet seconds and radians in all of them to avoid any problem with units [Our calculation (above) allows many different types of units the units are internally converted before and after using the equations]

          Since total flowrate (Qt) is entered and headwater depth (Yh) is computed the equations below are solved simultaneously to

          determine Yh Outlet versus inlet control is determined by the equation resulting in a larger value for Yh

          All of the variables are defined below in the Variables section Pipe downstream invert elevation is defined as 00

          General EquationsQt = Qr + N Qp Sp = Sc - Yf Lp Ei = Lp Sp Eh = Ei + Yh V=Qp Av

          Tailwater Depth Yt

          Yt can be computed or input If it is computed Mannings equation is used (Chow 1959)

          Since Qt is input the above equations are solved numerically (backwards) for Yt

          Headwater depth Yh

          Yh is computed independently based on inlet and outlet control equations The equation that gives the larger value of Yh is

          considered to be the controlling mechanism and is reported

          Inlet Control (see below for values of constants C1 C2 C3 C4 C5)

          Outlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests computing Yv using the

          Manning equation If Yv is greater than D then Yv is set to D

          Unsubmerged Inlet (Normann 1985)

          fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (3 of 7)12112007 40331 PM

          Culvert Design Inlet and Outlet Control

          Submerged Inlet (Normann 1985)

          Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

          YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

          If Yhlt093D then Mannings equation (Chow 1959) is used

          Since Qp is input the above equations are solved numerically for Yt

          If Yhgt=093D Normann (1985) is used

          Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

          fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (4 of 7)12112007 40331 PM

          Culvert Design Inlet and Outlet Control

          Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

          Variables Back to calculation

          A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

          Av=Flow area in one pipe used for computing outlet velocity [ft2]

          b=Width of channel bottom [ft] Used for computing Yt

          C1 C2 C3 C4 C5=Constants for inlet control equations See values below

          D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

          Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

          Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

          g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

          Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

          (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

          the roadnc=Channel Manning n coefficient See values below

          np=Pipe (culvert) Manning n coefficient See values below

          N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

          Qr=Flowrate over the road (or dam) [cfs]

          Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

          Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

          Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

          Tc=Top width of flow in one pipe based on critical depth [ft]

          V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

          Yavg=Average water depth [ft]

          Yc=Critical water depth [ft]

          Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

          Yh=Headwater depth [ft]

          Yo=Water outlet depth [ft]

          Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

          Yv=Depth used for computing outlet velocity [ft]

          z1=Left side slope of existing natural channel [horizontalvertical]

          z2=Right side slope of existing natural channel [horizontalvertical]

          Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

          Ke are from Normann (1985)

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          Culvert Design Inlet and Outlet Control

          Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

          Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

          Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

          Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

          Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

          Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

          Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

          Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

          Clean and Straight 0030 Clean 0022

          Major Rivers 0035 Gravelly 0025

          Sluggish with Deep Pools 0040 Weedy 0030

          Stony Cobbles 0035

          Floodplains

          Pasture Farmland 0035 Heavy Brush 0075

          Light Brush 0050 Trees 015

          Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

          Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

          Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

          the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

          Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

          discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

          side slopesNeed Scgt0 Channel cannot be horizontal

          Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

          is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

          Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

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          Culvert Design Inlet and Outlet Control

          Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

          Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

          Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

          minimum and maximum are too close together to have good axis labels for the graph

          Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

          YtgtEr since the equations are only valid for Ytlt=Er

          References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

          French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

          Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

          LMNOLMNOengcom httpwwwlmnoengcom

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          Design of Circular Water Pipes using Hazen Williams Equation

          bull

          Design of Circular Pressurized Water Pipes

          Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

          temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

          ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

          Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

          LMNO Engineering home page Unit Conversions Page Trouble printing

          Register to enable Calculate button

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

          Piping Scenarios

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          Design of Circular Water Pipes using Hazen Williams Equation

          Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

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          Design of Circular Water Pipes using Hazen Williams Equation

          Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

          Steady State Energy Equation used for this page Back to CalculationsObtained from References

          Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

          k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

          Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

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          Design of Circular Water Pipes using Hazen Williams Equation

          Material C Material C

          Asbestos Cement 140 Copper 130-140

          Brass 130-140 Galvanized iron 120

          Brick sewer 100 Glass 140

          Cast-Iron Lead 130-140

          New unlined 130 Plastic 140-150

          10 yr old 107-113 Steel

          20 yr old 89-100 Coal-tar enamel lined 145-150

          30 yr old 75-90 New unlined 140-150

          40 yr old 64-83 Riveted 110

          ConcreteConcrete-lined

          Steel forms 140 Tin 130

          Wooden forms 120 Vitrif clay (good condition) 110-140

          Centrifugally spun 135 Wood stave (avg condition) 120

          Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

          Fitting Km Fitting Km

          Valves Elbows

          Globe fully open 10 Regular 90deg flanged 03

          Angle fully open 2 Regular 90deg threaded 15

          Gate fully open 015 Long radius 90deg flanged 02

          Gate 14 closed 026 Long radius 90deg threaded 07

          Gate 12 closed 21 Long radius 45deg threaded 02

          Gate 34 closed 17 Regular 45deg threaded 04

          Swing check forward flow 2

          Swing check backward flow infinity Tees

          Line flow flanged 02

          180deg return bends Line flow threaded 09

          Flanged 02 Branch flow flanged 10

          Threaded 15 Branch flow threaded 20

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          Design of Circular Water Pipes using Hazen Williams Equation

          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

          Square Connection 05 Square Connection 10

          Rounded Connection 02 Rounded Connection 10

          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

          copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

          LMNOLMNOengcom httpwwwlmnoengcom

          fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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          Gradually Varied Flow Calculation Backwater profile

          bull

          Gradually Varied Flow in Trapezoidal Channel

          Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

          Compute normal and critical depths

          To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

          LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

          Cross-Section of Trapezoidal Channel

          Gradually Varied Flow Profiles

          CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

          middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

          Gradually Varied Flow Calculation Backwater profile

          Links on this page Equations Variables Manning n coefficients Error messages References

          Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

          equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

          calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

          The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

          Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

          using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

          References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

          empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

          Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

          Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

          1985) along with the fundamental equations above to solve for Yc

          Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

          the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

          Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

          critical (C) The slopes are further classified by a number (1 2 or 3) as follows

          For mild slopes (YngtYc)

          If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

          water depth gets closer to Yn as the calculation proceeds further and further upstream

          If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

          Gradually Varied Flow Calculation Backwater profile

          The water depth gets closer to Yn as the calculation proceeds further and further upstream

          If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

          is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

          For steep slopes (YcgtYn)

          If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

          is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

          If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

          water depth gets closer to Yn as the calculation proceeds further and further downstream

          If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

          water depth gets closer to Yn as the calculation proceeds further and further downstream

          For critical slopes (Yc=Yn)

          If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

          water depth gets closer to Yn as the calculation proceeds further and further upstream

          If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

          water depth gets closer to Yn as the calculation proceeds further and further downstream

          There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

          Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

          At control section i=1 and Yi=Ys

          Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

          Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

          Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

          P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

          differential depth increments (this is the basis of the Improved Euler method)

          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

          Gradually Varied Flow Calculation Backwater profile

          Then repeat the loop by incrementing i

          The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

          Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

          Ap=Area at Xp [m2]

          A2=Area for intermediate computation in Improved Euler method [m2]

          dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

          (dYdX)2=Second depth increment for Improved Euler method [m]

          B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

          Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

          Epy=Elevation of water surface at Xp [m]

          F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

          g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

          P2=Second wetted perimeter computed in Improved Euler method [m]

          Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

          Sf1=First energy slope for Improved Euler method [dimensionless]

          Sf2=Second energy slope for Improved Euler method [dimensionless]

          T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

          T2=Second top width computed in Improved Euler method [m]

          Tp=Top width at Xp [m]

          V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

          X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

          is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

          Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

          automatically set Xp to Xmax

          Y=Water depth [m]Yc=Critical depth [m]

          Yi=Water depth computed at successive i intervals in Improved Euler method [m]

          Yn=Normal depth [m]

          Yp=Depth at Xp [m]

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          Gradually Varied Flow Calculation Backwater profile

          Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

          Y2=Second depth computed in Improved Euler method [m]

          Z1=One channel side slope (horizontal to vertical ratio) [mm]

          Z2=The other channel side slope (horizontal to vertical ratio) [mm]

          Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

          Material Manning n Material Manning n

          Natural Streams Excavated Earth Channels

          Clean and Straight 0030 Clean 0022

          Major Rivers 0035 Gravelly 0025

          Sluggish with Deep Pools 0040 Weedy 0030

          Stony Cobbles 0035

          Metals Floodplains

          Brass 0011 Pasture Farmland 0035

          Cast Iron 0013 Light Brush 0050

          Smooth Steel 0012 Heavy Brush 0075

          Corrugated Metal 0022 Trees 015

          Non-Metals

          Glass 0010 Finished Concrete 0012

          Clay Tile 0014 Unfinished Concrete 0014

          Brickwork 0015 Gravel 0029

          Asphalt 0016 Earth 0025

          Masonry 0025 Planed Wood 0012

          Unplaned Wood 0013

          Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

          20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

          Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

          Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

          is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

          References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

          Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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          Gradually Varied Flow Calculation Backwater profile

          Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

          French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

          Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

          Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

          Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

          Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

          copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

          LMNOLMNOengcom httpwwwlmnoengcom

          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

          Hydraulic Jump Calculation

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          Hydraulic Jump in Horizontal Rectangular Channel

          Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

          jump length and energy loss

          To LMNO Engineering home page (all calculations) Related open channel calculations

          Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

          Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

          fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

          Hydraulic Jump Calculation

          Register to enable Calculate button

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          Equations

          Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

          V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

          L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

          where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

          Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

          What is a Hydraulic Jump

          A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

          According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

          oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

          occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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          Hydraulic Jump Calculation

          MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

          Need F1 gt1 Upstream flow must be supercritical

          ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

          copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

          LMNOLMNOengcom httpwwwlmnoengcom

          fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

          Manning Equation

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          Mannings Equation Calculator Software The open channel flow software website

          LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

          Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

          and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

          The product AP is also known as the hydraulic radius Rh

          fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

          Non-Circular Open Channel Geometry

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          Geometric Calculations for Non-Circular Partially Filled Channels

          The open channel flow calculations software website

          Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

          Equations (note that R=AP)

          fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

          bull

          Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

          losses

          Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

          pipe Dont have to use all the pipes or nodes

          To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

          Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

          Register to fully enable Calculate button

          Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

          IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

          Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

          The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

          Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

          Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

          1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

          Pipe flows are adjusted iteratively using the following equation

          until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

          Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

          Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

          Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

          where log is base 10 logarithm and ln is natural logarithm Variable definitions

          Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

          Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

          Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

          Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

          The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

          ApplicationsThe pipe network calculation has many applications Two examples will be provided

          1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

          pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

          2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

          Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

          Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

          Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

          A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

          n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

          Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

          Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

          References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

          Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

          LMNOLMNOengcom httpwwwlmnoengcom

          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          bull

          Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

          Weisbach - Moody friction losses)

          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

          (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

          Parabolic shaped pump curve is formed from the two points

          ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

          curve Hazen-Williams with pump curve

          Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

          Register to enable Calculate button

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

          IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

          A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

          For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

          (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

          Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

          calculation will look like

          The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

          Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

          Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

          is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

          defined for liquids

          Variables Units F=force L=length P=pressure T=time Back to Calculations

          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

          A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

          hf = Major losses for entire pipe [L] Also known as friction losses

          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

          hm = Minor losses for entire pipe [L]

          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

          K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

          for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

          P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

          location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

          zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

          this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

          v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

          Fitting K Fitting K

          Valves Elbows

          Globe fully open 10 Regular 90deg flanged 03

          Angle fully open 2 Regular 90deg threaded 15

          Gate fully open 015 Long radius 90deg flanged 02

          Gate 14 closed 026 Long radius 90deg threaded 07

          Gate 12 closed 21 Long radius 45deg threaded 02

          Gate 34 closed 17 Regular 45deg threaded 04

          Swing check forward flow 2

          Swing check backward flow infinity Tees

          Line flow flanged 02

          180deg return bends Line flow threaded 09

          Flanged 02 Branch flow flanged 10

          Threaded 15 Branch flow threaded 20

          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          Square Connection 05 Square Connection 10

          Rounded Connection 02 Rounded Connection 10

          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

          Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

          The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

          Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

          the pipe or K for the suction pipe was entered as greater than K for the entire system

          Other messagesK must be gt=1 If Q known Solve for D and V

          3=0 then K must be gt 1 in order to solve

          Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

          reservoirs are defined to be at zero pressure thus zero pressure difference

          Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

          Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

          References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

          Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

          Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

          Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

          Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

          White F M 1979 Fluid Mechanics McGraw-Hill Inc

          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

          LMNOLMNOengcom httpwwwlmnoengcom

          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          bull

          Circular Pressurized Water Pipes with Pump Curve

          (Hazen Williams)

          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

          (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

          temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

          ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

          curve Darcy-Weisbach with pump curve

          Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

          Register to enable Calculate button

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

          IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

          function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

          manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

          Equations and Methodology Back to Calculations

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

          calculation will look like

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

          Variables Units L=length P=pressure T=time Back to Calculations

          A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

          g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

          hf = Major losses for entire pipe [L]

          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

          hm = Minor losses for entire pipe [L]

          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

          k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

          L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

          program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

          location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

          zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

          this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

          Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

          available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

          and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

          Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

          Material C Material C

          Asbestos Cement 140 Copper 130-140

          Brass 130-140 Galvanized iron 120

          Brick sewer 100 Glass 140

          Cast-Iron Lead 130-140

          New unlined 130 Plastic 140-150

          10 yr old 107-113 Steel

          20 yr old 89-100 Coal-tar enamel lined 145-150

          30 yr old 75-90 New unlined 140-150

          40 yr old 64-83 Riveted 110

          ConcreteConcrete-lined

          Steel forms 140 Tin 130

          Wooden forms 120 Vitrif clay (good condition) 110-140

          Centrifugally spun 135 Wood stave (avg condition) 120

          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

          Fitting K Fitting K

          Valves Elbows

          Globe fully open 10 Regular 90deg flanged 03

          Angle fully open 2 Regular 90deg threaded 15

          Gate fully open 015 Long radius 90deg flanged 02

          Gate 14 closed 026 Long radius 90deg threaded 07

          Gate 12 closed 21 Long radius 45deg threaded 02

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          Gate 34 closed 17 Regular 45deg threaded 04

          Swing check forward flow 2

          Swing check backward flow infinity Tees

          Line flow flanged 02

          180deg return bends Line flow threaded 09

          Flanged 02 Branch flow flanged 10

          Threaded 15 Branch flow threaded 20

          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

          Square Connection 05 Square Connection 10

          Rounded Connection 02 Rounded Connection 10

          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

          Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

          entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

          One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

          entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

          P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

          to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

          the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

          and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

          pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

          result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

          be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

          lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

          LMNOLMNOengcom httpwwwlmnoengcom

          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

          bull

          Trapezoidal Open Channel Design Calculation

          Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

          Froude number Manning coefficient channel slope

          To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

          Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

          Register to enable Calculate button

          Your browser does not support Java or Java is disabled in your browser Calculation should be here

          Links on this page Introduction Variables Manning n coefficients Error Messages References

          IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

          beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

          The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

          In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

          Variables [] indicates dimensions To calculation

          A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

          divided by vertical distance

          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

          Oslash = Angle formed by S

          Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

          Material Manning n Material Manning n

          Natural Streams Excavated Earth Channels

          Clean and Straight 0030 Clean 0022

          Major Rivers 0035 Gravelly 0025

          Sluggish with Deep Pools 0040 Weedy 0030

          Stony Cobbles 0035

          Metals Floodplains

          Brass 0011 Pasture Farmland 0035

          Cast Iron 0013 Light Brush 0050

          Smooth Steel 0012 Heavy Brush 0075

          Corrugated Metal 0022 Trees 015

          Non-Metals

          Glass 0010 Finished Concrete 0012

          Clay Tile 0014 Unfinished Concrete 0014

          Brickwork 0015 Gravel 0029

          Asphalt 0016 Earth 0025

          Masonry 0025 Planed Wood 0012

          Unplaned Wood 0013

          Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

          Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

          Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

          Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

          The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

          cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

          simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

          The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

          References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

          a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

          c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

          e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

          Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

          French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

          d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

          Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

          b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

          7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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          Waterhammer surge analysis and transient analysis pipe flow modeling software

          Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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          Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

          View the version 40 New Features List

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          AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

          fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

          Waterhammer surge analysis and transient analysis pipe flow modeling software

          components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

          From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

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          copy 2001-2007 Applied Flow Technology All Rights Reserved

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          • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
            • Local Disk
              • Circular Culvert Design Calculations Software Equations
                  • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                    • Local Disk
                      • Culvert Design Inlet and Outlet Control
                          • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                              • Design of Circular Water Pipes using Hazen Williams Equation
                                  • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                    • Local Disk
                                      • DPlot Graphing Software for Scientists and Engineers - Home Page
                                          • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                              • Gradually Varied Flow Calculation Backwater profile
                                                  • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                      • Hydraulic Jump Calculation
                                                          • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                              • Manning Equation
                                                                  • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                      • Non-Circular Open Channel Geometry
                                                                          • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                            • Local Disk
                                                                              • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                  • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                    • Local Disk
                                                                                      • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                          • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                              • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                      • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                          • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                            • Local Disk
                                                                                                              • Waterhammer surge analysis and transient analysis pipe flow modeling software

            Culvert Design Inlet and Outlet Control

            CMP Headwall = Corrugated metal pipe with headwall at inlet CMP Mitered = Corrugated metal pipe mitered to slope at inlet CMP Projecting = Corrugated metal pipe projecting at inlet

            middot Unitsm=meters ft=feet ls=litersec cfm=cubic feet per minute cfs=cubic feet per second gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day MGD=Millions of US gallons per day

            middot You can enter tailwater depth (Yt) as a negative number if flow from the culvert drops down to a receiving channel You dont

            need to know the exact elevation drop entering any negative number for Yt will have the same effect

            middot The phrase Inlet Control or Outlet Control that appears in the upper right hand corner of the calculation refers to the type of control for the total flow (Qt) entered in the calculations upper left hand corner The graph below the calculation plots headwater

            depth (Yh) for the range of Qt min to Qt max entered in the bottom right hand corner The type of control may change from one part

            of the graph to another as Qt changes

            Introduction Culverts have been utilized for thousands of years as a means to transmit water under walkways or roads Often a culvert is simply installed without much thought to how much water it needs to convey under extreme conditions If a culvert cannot convey all of the incoming water then the water will flow over or around the pipe or simply back up behind the culvert creating a pond or reservoir If any of these conditions are unacceptable then the proper culvert diameter and number of culverts must be selected prior to installation in order to convey all of the anticipated water through the pipe(s) This calculation helps the designer size culverts as well as present a headwater depth vs discharge rating curve

            The LMNO Engineering calculation is primarily based on the methodology presented in Hydraulic Design of Highway Culverts by Normann (1985) and published by the US Department of Transportations Federal Highway Administration It is also known as HDS-5 (Hydraulic Design Series No 5) HDS-5 focuses on culvert design Culvert design is usually based on the maximum acceptable discharge - thus the HDS-5 methodology is geared toward culverts flowing full with water possibly flowing over the road above the culvert In addition to programming the HDS-5 methodology LMNO Engineering wished to compute headwater depths for lesser flows Therefore in addition to the HDS-5 methodology we have added the Manning equation for culverts flowing partially full The HDS-5 methodology also assumes that the user knows the tailwater depth (Yt) before using the

            methodology Though Yt can be found by field measurements it is often computed in the office using Mannings equation based on

            bottom width side slopes channel roughness and channel slope Therefore LMNO Engineering added the additional feature of a built-in subroutine for computing Yt for trapezoidal channels Note that for the graphing portion of our calculation Yt is re-

            computed for the entire range of flows (Qt) shown on the graph (unless the user specifically inputs Yt)

            As explained in Normann 1985 (also known as HDS-5) the discharge through a culvert is controlled by either inlet or outlet conditions Inlet control means that flow through the culvert is limited by culvert entrance characteristics Outlet control means that flow through the culvert is limited by friction between the flowing water and the culvert barrel The term outlet control is a bit of a misnomer because friction along the entire length of the culvert is as important as the actual outlet condition (the tailwater depth) Inlet control most often occurs for short smooth or greatly downward sloping culverts Outlet control governs for long rough or slightly sloping culverts The type of control also depends on the flowrate For a given culvert installation inlet control may govern for a certain range of flows while outlet control may govern for other flowrates If the flowrate is large enough water could go over the road (or dam) In this case the calculation automatically computes the amount of water going over the road and through each culvert as well as the headwater depth

            If you have surfed around our website you may have noticed our other calculations for circular culverts We have a calculation using Mannings equation for design of circular culverts Since it uses Mannings equation it assumes the culvert is long enough so that normal depth is achieved We also have a calculation for computing discharge from the exit depth (end depth) in a circular culvert - very useful for flowrate measurement in the field For flows under pressure we have several calculations listed under the Pipe Flow category on our home page

            fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (2 of 7)12112007 40331 PM

            Culvert Design Inlet and Outlet Control

            Equations and Methodology Back to calculationThe LMNO Engineering methodology generally follows that of Normann (1985 also known as HDS-5) However the Normann methodology is mainly for culvert design Culvert design usually involves the largest expected flowrate We wanted to write a calculation that also determines headwater depth for small flowrates Therefore in addition to the Normann methodology we have incorporated Mannings equation for outlet control when the headwater depth is less than 093 times the culvert diameter 093D is used since it is the depth at which discharge through a partially full culvert is a maximum (Chow 1959) At depths greater than 093D and for full flow the Nomann (1985) equation is used for outlet control For inlet control our calculation uses Normanns equations

            Many of the equations shown below are empirical and require US Customary units (feet seconds and radians) Some of the equations are based on first principles and are compatible with any consistent set of units (eg SI) However to keep this web page from being too busy we have refrained from indicating which equations are empirical and which are fundamental If you work through the equations by hand please use feet seconds and radians in all of them to avoid any problem with units [Our calculation (above) allows many different types of units the units are internally converted before and after using the equations]

            Since total flowrate (Qt) is entered and headwater depth (Yh) is computed the equations below are solved simultaneously to

            determine Yh Outlet versus inlet control is determined by the equation resulting in a larger value for Yh

            All of the variables are defined below in the Variables section Pipe downstream invert elevation is defined as 00

            General EquationsQt = Qr + N Qp Sp = Sc - Yf Lp Ei = Lp Sp Eh = Ei + Yh V=Qp Av

            Tailwater Depth Yt

            Yt can be computed or input If it is computed Mannings equation is used (Chow 1959)

            Since Qt is input the above equations are solved numerically (backwards) for Yt

            Headwater depth Yh

            Yh is computed independently based on inlet and outlet control equations The equation that gives the larger value of Yh is

            considered to be the controlling mechanism and is reported

            Inlet Control (see below for values of constants C1 C2 C3 C4 C5)

            Outlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests computing Yv using the

            Manning equation If Yv is greater than D then Yv is set to D

            Unsubmerged Inlet (Normann 1985)

            fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (3 of 7)12112007 40331 PM

            Culvert Design Inlet and Outlet Control

            Submerged Inlet (Normann 1985)

            Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

            YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

            If Yhlt093D then Mannings equation (Chow 1959) is used

            Since Qp is input the above equations are solved numerically for Yt

            If Yhgt=093D Normann (1985) is used

            Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

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            Culvert Design Inlet and Outlet Control

            Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

            Variables Back to calculation

            A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

            Av=Flow area in one pipe used for computing outlet velocity [ft2]

            b=Width of channel bottom [ft] Used for computing Yt

            C1 C2 C3 C4 C5=Constants for inlet control equations See values below

            D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

            Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

            Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

            g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

            Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

            (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

            the roadnc=Channel Manning n coefficient See values below

            np=Pipe (culvert) Manning n coefficient See values below

            N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

            Qr=Flowrate over the road (or dam) [cfs]

            Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

            Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

            Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

            Tc=Top width of flow in one pipe based on critical depth [ft]

            V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

            Yavg=Average water depth [ft]

            Yc=Critical water depth [ft]

            Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

            Yh=Headwater depth [ft]

            Yo=Water outlet depth [ft]

            Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

            Yv=Depth used for computing outlet velocity [ft]

            z1=Left side slope of existing natural channel [horizontalvertical]

            z2=Right side slope of existing natural channel [horizontalvertical]

            Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

            Ke are from Normann (1985)

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            Culvert Design Inlet and Outlet Control

            Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

            Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

            Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

            Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

            Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

            Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

            Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

            Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

            Clean and Straight 0030 Clean 0022

            Major Rivers 0035 Gravelly 0025

            Sluggish with Deep Pools 0040 Weedy 0030

            Stony Cobbles 0035

            Floodplains

            Pasture Farmland 0035 Heavy Brush 0075

            Light Brush 0050 Trees 015

            Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

            Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

            Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

            the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

            Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

            discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

            side slopesNeed Scgt0 Channel cannot be horizontal

            Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

            is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

            Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

            fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

            Culvert Design Inlet and Outlet Control

            Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

            Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

            Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

            minimum and maximum are too close together to have good axis labels for the graph

            Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

            YtgtEr since the equations are only valid for Ytlt=Er

            References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

            French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

            Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

            LMNOLMNOengcom httpwwwlmnoengcom

            fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

            Design of Circular Water Pipes using Hazen Williams Equation

            bull

            Design of Circular Pressurized Water Pipes

            Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

            temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

            ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

            Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

            LMNO Engineering home page Unit Conversions Page Trouble printing

            Register to enable Calculate button

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

            Piping Scenarios

            fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

            Design of Circular Water Pipes using Hazen Williams Equation

            Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

            fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

            Design of Circular Water Pipes using Hazen Williams Equation

            Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

            Steady State Energy Equation used for this page Back to CalculationsObtained from References

            Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

            k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

            Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

            fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

            Design of Circular Water Pipes using Hazen Williams Equation

            Material C Material C

            Asbestos Cement 140 Copper 130-140

            Brass 130-140 Galvanized iron 120

            Brick sewer 100 Glass 140

            Cast-Iron Lead 130-140

            New unlined 130 Plastic 140-150

            10 yr old 107-113 Steel

            20 yr old 89-100 Coal-tar enamel lined 145-150

            30 yr old 75-90 New unlined 140-150

            40 yr old 64-83 Riveted 110

            ConcreteConcrete-lined

            Steel forms 140 Tin 130

            Wooden forms 120 Vitrif clay (good condition) 110-140

            Centrifugally spun 135 Wood stave (avg condition) 120

            Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

            Fitting Km Fitting Km

            Valves Elbows

            Globe fully open 10 Regular 90deg flanged 03

            Angle fully open 2 Regular 90deg threaded 15

            Gate fully open 015 Long radius 90deg flanged 02

            Gate 14 closed 026 Long radius 90deg threaded 07

            Gate 12 closed 21 Long radius 45deg threaded 02

            Gate 34 closed 17 Regular 45deg threaded 04

            Swing check forward flow 2

            Swing check backward flow infinity Tees

            Line flow flanged 02

            180deg return bends Line flow threaded 09

            Flanged 02 Branch flow flanged 10

            Threaded 15 Branch flow threaded 20

            fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

            Design of Circular Water Pipes using Hazen Williams Equation

            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

            Square Connection 05 Square Connection 10

            Rounded Connection 02 Rounded Connection 10

            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

            copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

            LMNOLMNOengcom httpwwwlmnoengcom

            fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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            DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

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            DPlot Graphing Software for Scientists and Engineers - Home Page

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            NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

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            Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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            DPlot Graphing Software for Scientists and Engineers - Home Page

            or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

            DPlot AccessoriesDo you need a new coffee cup mouse pad or golf shirt Of course you do Visit our online Accessories Store today

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            Gradually Varied Flow Calculation Backwater profile

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            Gradually Varied Flow in Trapezoidal Channel

            Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

            Compute normal and critical depths

            To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

            LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

            Cross-Section of Trapezoidal Channel

            Gradually Varied Flow Profiles

            CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

            middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

            Gradually Varied Flow Calculation Backwater profile

            Links on this page Equations Variables Manning n coefficients Error messages References

            Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

            equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

            calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

            The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

            Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

            using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

            References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

            empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

            Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

            Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

            1985) along with the fundamental equations above to solve for Yc

            Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

            the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

            Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

            critical (C) The slopes are further classified by a number (1 2 or 3) as follows

            For mild slopes (YngtYc)

            If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

            water depth gets closer to Yn as the calculation proceeds further and further upstream

            If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

            Gradually Varied Flow Calculation Backwater profile

            The water depth gets closer to Yn as the calculation proceeds further and further upstream

            If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

            is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

            For steep slopes (YcgtYn)

            If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

            is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

            If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

            water depth gets closer to Yn as the calculation proceeds further and further downstream

            If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

            water depth gets closer to Yn as the calculation proceeds further and further downstream

            For critical slopes (Yc=Yn)

            If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

            water depth gets closer to Yn as the calculation proceeds further and further upstream

            If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

            water depth gets closer to Yn as the calculation proceeds further and further downstream

            There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

            Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

            At control section i=1 and Yi=Ys

            Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

            Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

            Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

            P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

            differential depth increments (this is the basis of the Improved Euler method)

            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

            Gradually Varied Flow Calculation Backwater profile

            Then repeat the loop by incrementing i

            The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

            Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

            Ap=Area at Xp [m2]

            A2=Area for intermediate computation in Improved Euler method [m2]

            dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

            (dYdX)2=Second depth increment for Improved Euler method [m]

            B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

            Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

            Epy=Elevation of water surface at Xp [m]

            F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

            g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

            P2=Second wetted perimeter computed in Improved Euler method [m]

            Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

            Sf1=First energy slope for Improved Euler method [dimensionless]

            Sf2=Second energy slope for Improved Euler method [dimensionless]

            T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

            T2=Second top width computed in Improved Euler method [m]

            Tp=Top width at Xp [m]

            V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

            X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

            is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

            Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

            automatically set Xp to Xmax

            Y=Water depth [m]Yc=Critical depth [m]

            Yi=Water depth computed at successive i intervals in Improved Euler method [m]

            Yn=Normal depth [m]

            Yp=Depth at Xp [m]

            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

            Gradually Varied Flow Calculation Backwater profile

            Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

            Y2=Second depth computed in Improved Euler method [m]

            Z1=One channel side slope (horizontal to vertical ratio) [mm]

            Z2=The other channel side slope (horizontal to vertical ratio) [mm]

            Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

            Material Manning n Material Manning n

            Natural Streams Excavated Earth Channels

            Clean and Straight 0030 Clean 0022

            Major Rivers 0035 Gravelly 0025

            Sluggish with Deep Pools 0040 Weedy 0030

            Stony Cobbles 0035

            Metals Floodplains

            Brass 0011 Pasture Farmland 0035

            Cast Iron 0013 Light Brush 0050

            Smooth Steel 0012 Heavy Brush 0075

            Corrugated Metal 0022 Trees 015

            Non-Metals

            Glass 0010 Finished Concrete 0012

            Clay Tile 0014 Unfinished Concrete 0014

            Brickwork 0015 Gravel 0029

            Asphalt 0016 Earth 0025

            Masonry 0025 Planed Wood 0012

            Unplaned Wood 0013

            Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

            20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

            Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

            Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

            is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

            References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

            Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

            Gradually Varied Flow Calculation Backwater profile

            Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

            French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

            Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

            Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

            Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

            Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

            copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

            LMNOLMNOengcom httpwwwlmnoengcom

            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

            Hydraulic Jump Calculation

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            Hydraulic Jump in Horizontal Rectangular Channel

            Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

            jump length and energy loss

            To LMNO Engineering home page (all calculations) Related open channel calculations

            Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

            Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

            Hydraulic Jump Calculation

            Register to enable Calculate button

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            Equations

            Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

            V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

            L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

            where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

            Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

            What is a Hydraulic Jump

            A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

            According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

            oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

            occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

            Hydraulic Jump Calculation

            MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

            Need F1 gt1 Upstream flow must be supercritical

            ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

            copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

            LMNOLMNOengcom httpwwwlmnoengcom

            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

            Manning Equation

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            Mannings Equation Calculator Software The open channel flow software website

            LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

            Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

            and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

            The product AP is also known as the hydraulic radius Rh

            fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

            Non-Circular Open Channel Geometry

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            Geometric Calculations for Non-Circular Partially Filled Channels

            The open channel flow calculations software website

            Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

            Equations (note that R=AP)

            fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

            bull

            Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

            losses

            Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

            pipe Dont have to use all the pipes or nodes

            To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

            Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

            Register to fully enable Calculate button

            Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

            IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

            Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

            The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

            Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

            Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

            1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

            Pipe flows are adjusted iteratively using the following equation

            until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

            Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

            Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

            Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

            where log is base 10 logarithm and ln is natural logarithm Variable definitions

            Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

            Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

            Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

            Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

            The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

            ApplicationsThe pipe network calculation has many applications Two examples will be provided

            1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

            pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

            2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

            Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

            Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

            Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

            A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

            n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

            Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

            Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

            References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

            Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

            LMNOLMNOengcom httpwwwlmnoengcom

            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            bull

            Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

            Weisbach - Moody friction losses)

            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

            (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

            Parabolic shaped pump curve is formed from the two points

            ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

            curve Hazen-Williams with pump curve

            Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

            Register to enable Calculate button

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

            IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

            A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

            For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

            (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

            Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

            calculation will look like

            The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

            Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

            Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

            is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

            defined for liquids

            Variables Units F=force L=length P=pressure T=time Back to Calculations

            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

            A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

            hf = Major losses for entire pipe [L] Also known as friction losses

            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

            hm = Minor losses for entire pipe [L]

            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

            K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

            for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

            P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

            location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

            zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

            this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

            v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

            Fitting K Fitting K

            Valves Elbows

            Globe fully open 10 Regular 90deg flanged 03

            Angle fully open 2 Regular 90deg threaded 15

            Gate fully open 015 Long radius 90deg flanged 02

            Gate 14 closed 026 Long radius 90deg threaded 07

            Gate 12 closed 21 Long radius 45deg threaded 02

            Gate 34 closed 17 Regular 45deg threaded 04

            Swing check forward flow 2

            Swing check backward flow infinity Tees

            Line flow flanged 02

            180deg return bends Line flow threaded 09

            Flanged 02 Branch flow flanged 10

            Threaded 15 Branch flow threaded 20

            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            Square Connection 05 Square Connection 10

            Rounded Connection 02 Rounded Connection 10

            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

            Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

            The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

            Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

            the pipe or K for the suction pipe was entered as greater than K for the entire system

            Other messagesK must be gt=1 If Q known Solve for D and V

            3=0 then K must be gt 1 in order to solve

            Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

            reservoirs are defined to be at zero pressure thus zero pressure difference

            Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

            Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

            References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

            Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

            Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

            Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

            Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

            White F M 1979 Fluid Mechanics McGraw-Hill Inc

            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

            LMNOLMNOengcom httpwwwlmnoengcom

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            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            bull

            Circular Pressurized Water Pipes with Pump Curve

            (Hazen Williams)

            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

            (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

            temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

            ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

            curve Darcy-Weisbach with pump curve

            Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

            Register to enable Calculate button

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

            IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

            function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

            manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

            Equations and Methodology Back to Calculations

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

            calculation will look like

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

            Variables Units L=length P=pressure T=time Back to Calculations

            A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

            g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

            hf = Major losses for entire pipe [L]

            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

            hm = Minor losses for entire pipe [L]

            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

            k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

            L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

            program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

            location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

            zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

            this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

            Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

            available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

            and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

            Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

            Material C Material C

            Asbestos Cement 140 Copper 130-140

            Brass 130-140 Galvanized iron 120

            Brick sewer 100 Glass 140

            Cast-Iron Lead 130-140

            New unlined 130 Plastic 140-150

            10 yr old 107-113 Steel

            20 yr old 89-100 Coal-tar enamel lined 145-150

            30 yr old 75-90 New unlined 140-150

            40 yr old 64-83 Riveted 110

            ConcreteConcrete-lined

            Steel forms 140 Tin 130

            Wooden forms 120 Vitrif clay (good condition) 110-140

            Centrifugally spun 135 Wood stave (avg condition) 120

            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

            Fitting K Fitting K

            Valves Elbows

            Globe fully open 10 Regular 90deg flanged 03

            Angle fully open 2 Regular 90deg threaded 15

            Gate fully open 015 Long radius 90deg flanged 02

            Gate 14 closed 026 Long radius 90deg threaded 07

            Gate 12 closed 21 Long radius 45deg threaded 02

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            Gate 34 closed 17 Regular 45deg threaded 04

            Swing check forward flow 2

            Swing check backward flow infinity Tees

            Line flow flanged 02

            180deg return bends Line flow threaded 09

            Flanged 02 Branch flow flanged 10

            Threaded 15 Branch flow threaded 20

            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

            Square Connection 05 Square Connection 10

            Rounded Connection 02 Rounded Connection 10

            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

            Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

            entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

            One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

            entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

            P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

            to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

            the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

            and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

            pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

            result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

            be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

            lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

            LMNOLMNOengcom httpwwwlmnoengcom

            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

            bull

            Trapezoidal Open Channel Design Calculation

            Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

            Froude number Manning coefficient channel slope

            To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

            Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

            Register to enable Calculate button

            Your browser does not support Java or Java is disabled in your browser Calculation should be here

            Links on this page Introduction Variables Manning n coefficients Error Messages References

            IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

            beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

            The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

            In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

            Variables [] indicates dimensions To calculation

            A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

            divided by vertical distance

            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

            Oslash = Angle formed by S

            Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

            Material Manning n Material Manning n

            Natural Streams Excavated Earth Channels

            Clean and Straight 0030 Clean 0022

            Major Rivers 0035 Gravelly 0025

            Sluggish with Deep Pools 0040 Weedy 0030

            Stony Cobbles 0035

            Metals Floodplains

            Brass 0011 Pasture Farmland 0035

            Cast Iron 0013 Light Brush 0050

            Smooth Steel 0012 Heavy Brush 0075

            Corrugated Metal 0022 Trees 015

            Non-Metals

            Glass 0010 Finished Concrete 0012

            Clay Tile 0014 Unfinished Concrete 0014

            Brickwork 0015 Gravel 0029

            Asphalt 0016 Earth 0025

            Masonry 0025 Planed Wood 0012

            Unplaned Wood 0013

            Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

            Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

            Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

            Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

            The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

            cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

            simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

            The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

            References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

            a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

            c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

            e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

            Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

            French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

            d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

            Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

            b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

            7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

            Waterhammer surge analysis and transient analysis pipe flow modeling software

            Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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            Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

            View the version 40 New Features List

            Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

            AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

            Waterhammer surge analysis and transient analysis pipe flow modeling software

            components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

            From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

            View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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            copy 2001-2007 Applied Flow Technology All Rights Reserved

            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

            • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
              • Local Disk
                • Circular Culvert Design Calculations Software Equations
                    • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                      • Local Disk
                        • Culvert Design Inlet and Outlet Control
                            • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                              • Local Disk
                                • Design of Circular Water Pipes using Hazen Williams Equation
                                    • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                      • Local Disk
                                        • DPlot Graphing Software for Scientists and Engineers - Home Page
                                            • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                              • Local Disk
                                                • Gradually Varied Flow Calculation Backwater profile
                                                    • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                      • Local Disk
                                                        • Hydraulic Jump Calculation
                                                            • file____E__engineering_hydraulics_Manning20Equationpdf
                                                              • Local Disk
                                                                • Manning Equation
                                                                    • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                      • Local Disk
                                                                        • Non-Circular Open Channel Geometry
                                                                            • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                              • Local Disk
                                                                                • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                    • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                      • Local Disk
                                                                                        • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                            • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                              • Local Disk
                                                                                                • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                    • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                      • Local Disk
                                                                                                        • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                            • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                              • Local Disk
                                                                                                                • Waterhammer surge analysis and transient analysis pipe flow modeling software

              Culvert Design Inlet and Outlet Control

              Equations and Methodology Back to calculationThe LMNO Engineering methodology generally follows that of Normann (1985 also known as HDS-5) However the Normann methodology is mainly for culvert design Culvert design usually involves the largest expected flowrate We wanted to write a calculation that also determines headwater depth for small flowrates Therefore in addition to the Normann methodology we have incorporated Mannings equation for outlet control when the headwater depth is less than 093 times the culvert diameter 093D is used since it is the depth at which discharge through a partially full culvert is a maximum (Chow 1959) At depths greater than 093D and for full flow the Nomann (1985) equation is used for outlet control For inlet control our calculation uses Normanns equations

              Many of the equations shown below are empirical and require US Customary units (feet seconds and radians) Some of the equations are based on first principles and are compatible with any consistent set of units (eg SI) However to keep this web page from being too busy we have refrained from indicating which equations are empirical and which are fundamental If you work through the equations by hand please use feet seconds and radians in all of them to avoid any problem with units [Our calculation (above) allows many different types of units the units are internally converted before and after using the equations]

              Since total flowrate (Qt) is entered and headwater depth (Yh) is computed the equations below are solved simultaneously to

              determine Yh Outlet versus inlet control is determined by the equation resulting in a larger value for Yh

              All of the variables are defined below in the Variables section Pipe downstream invert elevation is defined as 00

              General EquationsQt = Qr + N Qp Sp = Sc - Yf Lp Ei = Lp Sp Eh = Ei + Yh V=Qp Av

              Tailwater Depth Yt

              Yt can be computed or input If it is computed Mannings equation is used (Chow 1959)

              Since Qt is input the above equations are solved numerically (backwards) for Yt

              Headwater depth Yh

              Yh is computed independently based on inlet and outlet control equations The equation that gives the larger value of Yh is

              considered to be the controlling mechanism and is reported

              Inlet Control (see below for values of constants C1 C2 C3 C4 C5)

              Outlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests computing Yv using the

              Manning equation If Yv is greater than D then Yv is set to D

              Unsubmerged Inlet (Normann 1985)

              fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (3 of 7)12112007 40331 PM

              Culvert Design Inlet and Outlet Control

              Submerged Inlet (Normann 1985)

              Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

              YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

              If Yhlt093D then Mannings equation (Chow 1959) is used

              Since Qp is input the above equations are solved numerically for Yt

              If Yhgt=093D Normann (1985) is used

              Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

              fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (4 of 7)12112007 40331 PM

              Culvert Design Inlet and Outlet Control

              Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

              Variables Back to calculation

              A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

              Av=Flow area in one pipe used for computing outlet velocity [ft2]

              b=Width of channel bottom [ft] Used for computing Yt

              C1 C2 C3 C4 C5=Constants for inlet control equations See values below

              D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

              Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

              Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

              g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

              Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

              (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

              the roadnc=Channel Manning n coefficient See values below

              np=Pipe (culvert) Manning n coefficient See values below

              N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

              Qr=Flowrate over the road (or dam) [cfs]

              Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

              Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

              Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

              Tc=Top width of flow in one pipe based on critical depth [ft]

              V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

              Yavg=Average water depth [ft]

              Yc=Critical water depth [ft]

              Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

              Yh=Headwater depth [ft]

              Yo=Water outlet depth [ft]

              Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

              Yv=Depth used for computing outlet velocity [ft]

              z1=Left side slope of existing natural channel [horizontalvertical]

              z2=Right side slope of existing natural channel [horizontalvertical]

              Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

              Ke are from Normann (1985)

              fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (5 of 7)12112007 40331 PM

              Culvert Design Inlet and Outlet Control

              Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

              Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

              Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

              Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

              Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

              Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

              Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

              Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

              Clean and Straight 0030 Clean 0022

              Major Rivers 0035 Gravelly 0025

              Sluggish with Deep Pools 0040 Weedy 0030

              Stony Cobbles 0035

              Floodplains

              Pasture Farmland 0035 Heavy Brush 0075

              Light Brush 0050 Trees 015

              Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

              Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

              Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

              the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

              Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

              discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

              side slopesNeed Scgt0 Channel cannot be horizontal

              Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

              is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

              Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

              fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

              Culvert Design Inlet and Outlet Control

              Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

              Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

              Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

              minimum and maximum are too close together to have good axis labels for the graph

              Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

              YtgtEr since the equations are only valid for Ytlt=Er

              References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

              French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

              Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

              LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

              Design of Circular Water Pipes using Hazen Williams Equation

              bull

              Design of Circular Pressurized Water Pipes

              Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

              temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

              ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

              Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

              LMNO Engineering home page Unit Conversions Page Trouble printing

              Register to enable Calculate button

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

              Piping Scenarios

              fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

              Design of Circular Water Pipes using Hazen Williams Equation

              Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

              fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

              Design of Circular Water Pipes using Hazen Williams Equation

              Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

              Steady State Energy Equation used for this page Back to CalculationsObtained from References

              Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

              k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

              All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

              Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

              fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

              Design of Circular Water Pipes using Hazen Williams Equation

              Material C Material C

              Asbestos Cement 140 Copper 130-140

              Brass 130-140 Galvanized iron 120

              Brick sewer 100 Glass 140

              Cast-Iron Lead 130-140

              New unlined 130 Plastic 140-150

              10 yr old 107-113 Steel

              20 yr old 89-100 Coal-tar enamel lined 145-150

              30 yr old 75-90 New unlined 140-150

              40 yr old 64-83 Riveted 110

              ConcreteConcrete-lined

              Steel forms 140 Tin 130

              Wooden forms 120 Vitrif clay (good condition) 110-140

              Centrifugally spun 135 Wood stave (avg condition) 120

              Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

              Fitting Km Fitting Km

              Valves Elbows

              Globe fully open 10 Regular 90deg flanged 03

              Angle fully open 2 Regular 90deg threaded 15

              Gate fully open 015 Long radius 90deg flanged 02

              Gate 14 closed 026 Long radius 90deg threaded 07

              Gate 12 closed 21 Long radius 45deg threaded 02

              Gate 34 closed 17 Regular 45deg threaded 04

              Swing check forward flow 2

              Swing check backward flow infinity Tees

              Line flow flanged 02

              180deg return bends Line flow threaded 09

              Flanged 02 Branch flow flanged 10

              Threaded 15 Branch flow threaded 20

              fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

              Design of Circular Water Pipes using Hazen Williams Equation

              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

              Square Connection 05 Square Connection 10

              Rounded Connection 02 Rounded Connection 10

              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

              copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

              LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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              DPlot Graphing Software for Scientists and Engineers - Home Page

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              DPlot Graphing Software for Scientists and Engineers - Home Page

              or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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              Gradually Varied Flow Calculation Backwater profile

              bull

              Gradually Varied Flow in Trapezoidal Channel

              Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

              Compute normal and critical depths

              To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

              LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

              Cross-Section of Trapezoidal Channel

              Gradually Varied Flow Profiles

              CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

              middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

              Gradually Varied Flow Calculation Backwater profile

              Links on this page Equations Variables Manning n coefficients Error messages References

              Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

              equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

              calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

              The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

              Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

              using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

              References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

              empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

              Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

              Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

              1985) along with the fundamental equations above to solve for Yc

              Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

              the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

              Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

              critical (C) The slopes are further classified by a number (1 2 or 3) as follows

              For mild slopes (YngtYc)

              If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

              water depth gets closer to Yn as the calculation proceeds further and further upstream

              If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

              Gradually Varied Flow Calculation Backwater profile

              The water depth gets closer to Yn as the calculation proceeds further and further upstream

              If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

              is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

              For steep slopes (YcgtYn)

              If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

              is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

              If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

              water depth gets closer to Yn as the calculation proceeds further and further downstream

              If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

              water depth gets closer to Yn as the calculation proceeds further and further downstream

              For critical slopes (Yc=Yn)

              If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

              water depth gets closer to Yn as the calculation proceeds further and further upstream

              If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

              water depth gets closer to Yn as the calculation proceeds further and further downstream

              There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

              Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

              At control section i=1 and Yi=Ys

              Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

              Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

              Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

              P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

              differential depth increments (this is the basis of the Improved Euler method)

              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

              Gradually Varied Flow Calculation Backwater profile

              Then repeat the loop by incrementing i

              The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

              Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

              Ap=Area at Xp [m2]

              A2=Area for intermediate computation in Improved Euler method [m2]

              dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

              (dYdX)2=Second depth increment for Improved Euler method [m]

              B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

              Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

              Epy=Elevation of water surface at Xp [m]

              F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

              g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

              P2=Second wetted perimeter computed in Improved Euler method [m]

              Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

              Sf1=First energy slope for Improved Euler method [dimensionless]

              Sf2=Second energy slope for Improved Euler method [dimensionless]

              T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

              T2=Second top width computed in Improved Euler method [m]

              Tp=Top width at Xp [m]

              V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

              X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

              is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

              Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

              automatically set Xp to Xmax

              Y=Water depth [m]Yc=Critical depth [m]

              Yi=Water depth computed at successive i intervals in Improved Euler method [m]

              Yn=Normal depth [m]

              Yp=Depth at Xp [m]

              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

              Gradually Varied Flow Calculation Backwater profile

              Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

              Y2=Second depth computed in Improved Euler method [m]

              Z1=One channel side slope (horizontal to vertical ratio) [mm]

              Z2=The other channel side slope (horizontal to vertical ratio) [mm]

              Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

              Material Manning n Material Manning n

              Natural Streams Excavated Earth Channels

              Clean and Straight 0030 Clean 0022

              Major Rivers 0035 Gravelly 0025

              Sluggish with Deep Pools 0040 Weedy 0030

              Stony Cobbles 0035

              Metals Floodplains

              Brass 0011 Pasture Farmland 0035

              Cast Iron 0013 Light Brush 0050

              Smooth Steel 0012 Heavy Brush 0075

              Corrugated Metal 0022 Trees 015

              Non-Metals

              Glass 0010 Finished Concrete 0012

              Clay Tile 0014 Unfinished Concrete 0014

              Brickwork 0015 Gravel 0029

              Asphalt 0016 Earth 0025

              Masonry 0025 Planed Wood 0012

              Unplaned Wood 0013

              Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

              20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

              Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

              Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

              is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

              References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

              Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

              Gradually Varied Flow Calculation Backwater profile

              Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

              French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

              Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

              Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

              Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

              Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

              copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

              LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

              Hydraulic Jump Calculation

              bull

              Hydraulic Jump in Horizontal Rectangular Channel

              Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

              jump length and energy loss

              To LMNO Engineering home page (all calculations) Related open channel calculations

              Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

              Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

              fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

              Hydraulic Jump Calculation

              Register to enable Calculate button

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              Equations

              Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

              V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

              L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

              where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

              Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

              What is a Hydraulic Jump

              A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

              According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

              oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

              occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

              fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

              Hydraulic Jump Calculation

              MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

              Need F1 gt1 Upstream flow must be supercritical

              ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

              copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

              LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

              Manning Equation

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              Mannings Equation Calculator Software The open channel flow software website

              LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

              Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

              and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

              The product AP is also known as the hydraulic radius Rh

              fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

              Non-Circular Open Channel Geometry

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              Geometric Calculations for Non-Circular Partially Filled Channels

              The open channel flow calculations software website

              Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

              Equations (note that R=AP)

              fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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              Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

              losses

              Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

              pipe Dont have to use all the pipes or nodes

              To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

              Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

              Register to fully enable Calculate button

              Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

              IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

              Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

              The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

              Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

              Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

              1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

              Pipe flows are adjusted iteratively using the following equation

              until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

              Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

              Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

              Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

              where log is base 10 logarithm and ln is natural logarithm Variable definitions

              Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

              Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

              Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

              Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

              The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

              ApplicationsThe pipe network calculation has many applications Two examples will be provided

              1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

              pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

              2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

              Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

              Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

              Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

              A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

              n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

              Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

              Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

              References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

              Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

              LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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              Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

              Weisbach - Moody friction losses)

              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

              (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

              Parabolic shaped pump curve is formed from the two points

              ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

              curve Hazen-Williams with pump curve

              Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

              Register to enable Calculate button

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

              IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

              A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

              For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

              (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

              Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

              Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

              calculation will look like

              The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

              Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

              Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

              is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

              defined for liquids

              Variables Units F=force L=length P=pressure T=time Back to Calculations

              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

              is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

              A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

              hf = Major losses for entire pipe [L] Also known as friction losses

              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

              hm = Minor losses for entire pipe [L]

              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

              K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

              for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

              P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

              location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

              zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

              V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

              this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

              v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

              Fitting K Fitting K

              Valves Elbows

              Globe fully open 10 Regular 90deg flanged 03

              Angle fully open 2 Regular 90deg threaded 15

              Gate fully open 015 Long radius 90deg flanged 02

              Gate 14 closed 026 Long radius 90deg threaded 07

              Gate 12 closed 21 Long radius 45deg threaded 02

              Gate 34 closed 17 Regular 45deg threaded 04

              Swing check forward flow 2

              Swing check backward flow infinity Tees

              Line flow flanged 02

              180deg return bends Line flow threaded 09

              Flanged 02 Branch flow flanged 10

              Threaded 15 Branch flow threaded 20

              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

              Square Connection 05 Square Connection 10

              Rounded Connection 02 Rounded Connection 10

              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

              Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

              The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

              Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

              the pipe or K for the suction pipe was entered as greater than K for the entire system

              Other messagesK must be gt=1 If Q known Solve for D and V

              3=0 then K must be gt 1 in order to solve

              Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

              reservoirs are defined to be at zero pressure thus zero pressure difference

              Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

              Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

              References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

              Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

              Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

              Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

              Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

              White F M 1979 Fluid Mechanics McGraw-Hill Inc

              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

              LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              bull

              Circular Pressurized Water Pipes with Pump Curve

              (Hazen Williams)

              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

              (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

              temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

              ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

              curve Darcy-Weisbach with pump curve

              Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

              Register to enable Calculate button

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

              IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

              function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

              manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

              Equations and Methodology Back to Calculations

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

              calculation will look like

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

              Variables Units L=length P=pressure T=time Back to Calculations

              A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

              g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

              hf = Major losses for entire pipe [L]

              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

              hm = Minor losses for entire pipe [L]

              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

              k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

              L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

              program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

              location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

              zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

              this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

              Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

              available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

              and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

              Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

              Material C Material C

              Asbestos Cement 140 Copper 130-140

              Brass 130-140 Galvanized iron 120

              Brick sewer 100 Glass 140

              Cast-Iron Lead 130-140

              New unlined 130 Plastic 140-150

              10 yr old 107-113 Steel

              20 yr old 89-100 Coal-tar enamel lined 145-150

              30 yr old 75-90 New unlined 140-150

              40 yr old 64-83 Riveted 110

              ConcreteConcrete-lined

              Steel forms 140 Tin 130

              Wooden forms 120 Vitrif clay (good condition) 110-140

              Centrifugally spun 135 Wood stave (avg condition) 120

              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

              Fitting K Fitting K

              Valves Elbows

              Globe fully open 10 Regular 90deg flanged 03

              Angle fully open 2 Regular 90deg threaded 15

              Gate fully open 015 Long radius 90deg flanged 02

              Gate 14 closed 026 Long radius 90deg threaded 07

              Gate 12 closed 21 Long radius 45deg threaded 02

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              Gate 34 closed 17 Regular 45deg threaded 04

              Swing check forward flow 2

              Swing check backward flow infinity Tees

              Line flow flanged 02

              180deg return bends Line flow threaded 09

              Flanged 02 Branch flow flanged 10

              Threaded 15 Branch flow threaded 20

              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

              Square Connection 05 Square Connection 10

              Rounded Connection 02 Rounded Connection 10

              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

              Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

              entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

              One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

              entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

              P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

              to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

              the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

              and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

              pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

              result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

              be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

              lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

              LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

              bull

              Trapezoidal Open Channel Design Calculation

              Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

              Froude number Manning coefficient channel slope

              To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

              Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

              Register to enable Calculate button

              Your browser does not support Java or Java is disabled in your browser Calculation should be here

              Links on this page Introduction Variables Manning n coefficients Error Messages References

              IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

              beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

              The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

              In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

              Variables [] indicates dimensions To calculation

              A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

              divided by vertical distance

              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

              Oslash = Angle formed by S

              Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

              Material Manning n Material Manning n

              Natural Streams Excavated Earth Channels

              Clean and Straight 0030 Clean 0022

              Major Rivers 0035 Gravelly 0025

              Sluggish with Deep Pools 0040 Weedy 0030

              Stony Cobbles 0035

              Metals Floodplains

              Brass 0011 Pasture Farmland 0035

              Cast Iron 0013 Light Brush 0050

              Smooth Steel 0012 Heavy Brush 0075

              Corrugated Metal 0022 Trees 015

              Non-Metals

              Glass 0010 Finished Concrete 0012

              Clay Tile 0014 Unfinished Concrete 0014

              Brickwork 0015 Gravel 0029

              Asphalt 0016 Earth 0025

              Masonry 0025 Planed Wood 0012

              Unplaned Wood 0013

              Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

              Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

              Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

              Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

              The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

              cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

              simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

              The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

              References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

              a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

              c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

              e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

              Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

              French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

              d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

              Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

              b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

              7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

              Waterhammer surge analysis and transient analysis pipe flow modeling software

              Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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              Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

              View the version 40 New Features List

              Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

              AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

              Waterhammer surge analysis and transient analysis pipe flow modeling software

              components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

              From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

              View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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              Details Views Brochure Demo

              copy 2001-2007 Applied Flow Technology All Rights Reserved

              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

              • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                • Local Disk
                  • Circular Culvert Design Calculations Software Equations
                      • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                        • Local Disk
                          • Culvert Design Inlet and Outlet Control
                              • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                • Local Disk
                                  • Design of Circular Water Pipes using Hazen Williams Equation
                                      • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                        • Local Disk
                                          • DPlot Graphing Software for Scientists and Engineers - Home Page
                                              • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                • Local Disk
                                                  • Gradually Varied Flow Calculation Backwater profile
                                                      • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                        • Local Disk
                                                          • Hydraulic Jump Calculation
                                                              • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                • Local Disk
                                                                  • Manning Equation
                                                                      • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                        • Local Disk
                                                                          • Non-Circular Open Channel Geometry
                                                                              • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                • Local Disk
                                                                                  • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                      • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                        • Local Disk
                                                                                          • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                              • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                • Local Disk
                                                                                                  • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                      • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                        • Local Disk
                                                                                                          • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                              • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                • Local Disk
                                                                                                                  • Waterhammer surge analysis and transient analysis pipe flow modeling software

                Culvert Design Inlet and Outlet Control

                Submerged Inlet (Normann 1985)

                Outlet ControlOutlet velocity (V) is computed based on what we call the velocity depth Yv Normann (1985) suggests If Ytlt=Yc then Yv=Yc If

                YcltYtltD then Yv=Yt If Ytgt=D then Yv=D

                If Yhlt093D then Mannings equation (Chow 1959) is used

                Since Qp is input the above equations are solved numerically for Yt

                If Yhgt=093D Normann (1985) is used

                Flow over Road (or Dam)If water flows over the road (or dam) then flow over the road is computed by (Normann 1985)

                fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (4 of 7)12112007 40331 PM

                Culvert Design Inlet and Outlet Control

                Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

                Variables Back to calculation

                A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

                Av=Flow area in one pipe used for computing outlet velocity [ft2]

                b=Width of channel bottom [ft] Used for computing Yt

                C1 C2 C3 C4 C5=Constants for inlet control equations See values below

                D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

                Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

                Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

                g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

                Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

                (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

                the roadnc=Channel Manning n coefficient See values below

                np=Pipe (culvert) Manning n coefficient See values below

                N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

                Qr=Flowrate over the road (or dam) [cfs]

                Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

                Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

                Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

                Tc=Top width of flow in one pipe based on critical depth [ft]

                V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

                Yavg=Average water depth [ft]

                Yc=Critical water depth [ft]

                Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

                Yh=Headwater depth [ft]

                Yo=Water outlet depth [ft]

                Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

                Yv=Depth used for computing outlet velocity [ft]

                z1=Left side slope of existing natural channel [horizontalvertical]

                z2=Right side slope of existing natural channel [horizontalvertical]

                Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

                Ke are from Normann (1985)

                fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (5 of 7)12112007 40331 PM

                Culvert Design Inlet and Outlet Control

                Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

                Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

                Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

                Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

                Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

                Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

                Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

                Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

                Clean and Straight 0030 Clean 0022

                Major Rivers 0035 Gravelly 0025

                Sluggish with Deep Pools 0040 Weedy 0030

                Stony Cobbles 0035

                Floodplains

                Pasture Farmland 0035 Heavy Brush 0075

                Light Brush 0050 Trees 015

                Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

                Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

                Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

                the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

                Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

                discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

                side slopesNeed Scgt0 Channel cannot be horizontal

                Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

                is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

                Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

                fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

                Culvert Design Inlet and Outlet Control

                Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

                Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

                Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

                minimum and maximum are too close together to have good axis labels for the graph

                Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

                YtgtEr since the equations are only valid for Ytlt=Er

                References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

                Design of Circular Water Pipes using Hazen Williams Equation

                bull

                Design of Circular Pressurized Water Pipes

                Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

                temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

                Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

                LMNO Engineering home page Unit Conversions Page Trouble printing

                Register to enable Calculate button

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

                Piping Scenarios

                fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

                Design of Circular Water Pipes using Hazen Williams Equation

                Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

                fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

                Design of Circular Water Pipes using Hazen Williams Equation

                Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

                Steady State Energy Equation used for this page Back to CalculationsObtained from References

                Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

                k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

                All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

                Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

                Design of Circular Water Pipes using Hazen Williams Equation

                Material C Material C

                Asbestos Cement 140 Copper 130-140

                Brass 130-140 Galvanized iron 120

                Brick sewer 100 Glass 140

                Cast-Iron Lead 130-140

                New unlined 130 Plastic 140-150

                10 yr old 107-113 Steel

                20 yr old 89-100 Coal-tar enamel lined 145-150

                30 yr old 75-90 New unlined 140-150

                40 yr old 64-83 Riveted 110

                ConcreteConcrete-lined

                Steel forms 140 Tin 130

                Wooden forms 120 Vitrif clay (good condition) 110-140

                Centrifugally spun 135 Wood stave (avg condition) 120

                Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                Fitting Km Fitting Km

                Valves Elbows

                Globe fully open 10 Regular 90deg flanged 03

                Angle fully open 2 Regular 90deg threaded 15

                Gate fully open 015 Long radius 90deg flanged 02

                Gate 14 closed 026 Long radius 90deg threaded 07

                Gate 12 closed 21 Long radius 45deg threaded 02

                Gate 34 closed 17 Regular 45deg threaded 04

                Swing check forward flow 2

                Swing check backward flow infinity Tees

                Line flow flanged 02

                180deg return bends Line flow threaded 09

                Flanged 02 Branch flow flanged 10

                Threaded 15 Branch flow threaded 20

                fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                Design of Circular Water Pipes using Hazen Williams Equation

                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                Square Connection 05 Square Connection 10

                Rounded Connection 02 Rounded Connection 10

                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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                DPlot Graphing Software for Scientists and Engineers - Home Page

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                DPlot Graphing Software for Scientists and Engineers - Home Page

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                Gradually Varied Flow Calculation Backwater profile

                bull

                Gradually Varied Flow in Trapezoidal Channel

                Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                Compute normal and critical depths

                To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                Cross-Section of Trapezoidal Channel

                Gradually Varied Flow Profiles

                CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                Gradually Varied Flow Calculation Backwater profile

                Links on this page Equations Variables Manning n coefficients Error messages References

                Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                1985) along with the fundamental equations above to solve for Yc

                Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                For mild slopes (YngtYc)

                If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                water depth gets closer to Yn as the calculation proceeds further and further upstream

                If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                Gradually Varied Flow Calculation Backwater profile

                The water depth gets closer to Yn as the calculation proceeds further and further upstream

                If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                For steep slopes (YcgtYn)

                If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                water depth gets closer to Yn as the calculation proceeds further and further downstream

                If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                water depth gets closer to Yn as the calculation proceeds further and further downstream

                For critical slopes (Yc=Yn)

                If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                water depth gets closer to Yn as the calculation proceeds further and further upstream

                If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                water depth gets closer to Yn as the calculation proceeds further and further downstream

                There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                At control section i=1 and Yi=Ys

                Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                differential depth increments (this is the basis of the Improved Euler method)

                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                Gradually Varied Flow Calculation Backwater profile

                Then repeat the loop by incrementing i

                The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                Ap=Area at Xp [m2]

                A2=Area for intermediate computation in Improved Euler method [m2]

                dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                (dYdX)2=Second depth increment for Improved Euler method [m]

                B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                Epy=Elevation of water surface at Xp [m]

                F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                P2=Second wetted perimeter computed in Improved Euler method [m]

                Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                Sf1=First energy slope for Improved Euler method [dimensionless]

                Sf2=Second energy slope for Improved Euler method [dimensionless]

                T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                T2=Second top width computed in Improved Euler method [m]

                Tp=Top width at Xp [m]

                V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                automatically set Xp to Xmax

                Y=Water depth [m]Yc=Critical depth [m]

                Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                Yn=Normal depth [m]

                Yp=Depth at Xp [m]

                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

                Gradually Varied Flow Calculation Backwater profile

                Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                Y2=Second depth computed in Improved Euler method [m]

                Z1=One channel side slope (horizontal to vertical ratio) [mm]

                Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                Material Manning n Material Manning n

                Natural Streams Excavated Earth Channels

                Clean and Straight 0030 Clean 0022

                Major Rivers 0035 Gravelly 0025

                Sluggish with Deep Pools 0040 Weedy 0030

                Stony Cobbles 0035

                Metals Floodplains

                Brass 0011 Pasture Farmland 0035

                Cast Iron 0013 Light Brush 0050

                Smooth Steel 0012 Heavy Brush 0075

                Corrugated Metal 0022 Trees 015

                Non-Metals

                Glass 0010 Finished Concrete 0012

                Clay Tile 0014 Unfinished Concrete 0014

                Brickwork 0015 Gravel 0029

                Asphalt 0016 Earth 0025

                Masonry 0025 Planed Wood 0012

                Unplaned Wood 0013

                Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                Gradually Varied Flow Calculation Backwater profile

                Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                Hydraulic Jump Calculation

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                Hydraulic Jump in Horizontal Rectangular Channel

                Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                jump length and energy loss

                To LMNO Engineering home page (all calculations) Related open channel calculations

                Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                Hydraulic Jump Calculation

                Register to enable Calculate button

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                Equations

                Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                What is a Hydraulic Jump

                A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                Hydraulic Jump Calculation

                MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                Need F1 gt1 Upstream flow must be supercritical

                ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                Manning Equation

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                Mannings Equation Calculator Software The open channel flow software website

                LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                The product AP is also known as the hydraulic radius Rh

                fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                Non-Circular Open Channel Geometry

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                Geometric Calculations for Non-Circular Partially Filled Channels

                The open channel flow calculations software website

                Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                Equations (note that R=AP)

                fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                losses

                Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                pipe Dont have to use all the pipes or nodes

                To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                Register to fully enable Calculate button

                Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                Pipe flows are adjusted iteratively using the following equation

                until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                where log is base 10 logarithm and ln is natural logarithm Variable definitions

                Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                ApplicationsThe pipe network calculation has many applications Two examples will be provided

                1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                Weisbach - Moody friction losses)

                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                Parabolic shaped pump curve is formed from the two points

                ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                curve Hazen-Williams with pump curve

                Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                Register to enable Calculate button

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                calculation will look like

                The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                defined for liquids

                Variables Units F=force L=length P=pressure T=time Back to Calculations

                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                hf = Major losses for entire pipe [L] Also known as friction losses

                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                hm = Minor losses for entire pipe [L]

                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                Fitting K Fitting K

                Valves Elbows

                Globe fully open 10 Regular 90deg flanged 03

                Angle fully open 2 Regular 90deg threaded 15

                Gate fully open 015 Long radius 90deg flanged 02

                Gate 14 closed 026 Long radius 90deg threaded 07

                Gate 12 closed 21 Long radius 45deg threaded 02

                Gate 34 closed 17 Regular 45deg threaded 04

                Swing check forward flow 2

                Swing check backward flow infinity Tees

                Line flow flanged 02

                180deg return bends Line flow threaded 09

                Flanged 02 Branch flow flanged 10

                Threaded 15 Branch flow threaded 20

                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                Square Connection 05 Square Connection 10

                Rounded Connection 02 Rounded Connection 10

                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                the pipe or K for the suction pipe was entered as greater than K for the entire system

                Other messagesK must be gt=1 If Q known Solve for D and V

                3=0 then K must be gt 1 in order to solve

                Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                reservoirs are defined to be at zero pressure thus zero pressure difference

                Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                White F M 1979 Fluid Mechanics McGraw-Hill Inc

                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                bull

                Circular Pressurized Water Pipes with Pump Curve

                (Hazen Williams)

                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                curve Darcy-Weisbach with pump curve

                Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                Register to enable Calculate button

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                Equations and Methodology Back to Calculations

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                calculation will look like

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                Variables Units L=length P=pressure T=time Back to Calculations

                A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                hf = Major losses for entire pipe [L]

                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                hm = Minor losses for entire pipe [L]

                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                Material C Material C

                Asbestos Cement 140 Copper 130-140

                Brass 130-140 Galvanized iron 120

                Brick sewer 100 Glass 140

                Cast-Iron Lead 130-140

                New unlined 130 Plastic 140-150

                10 yr old 107-113 Steel

                20 yr old 89-100 Coal-tar enamel lined 145-150

                30 yr old 75-90 New unlined 140-150

                40 yr old 64-83 Riveted 110

                ConcreteConcrete-lined

                Steel forms 140 Tin 130

                Wooden forms 120 Vitrif clay (good condition) 110-140

                Centrifugally spun 135 Wood stave (avg condition) 120

                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                Fitting K Fitting K

                Valves Elbows

                Globe fully open 10 Regular 90deg flanged 03

                Angle fully open 2 Regular 90deg threaded 15

                Gate fully open 015 Long radius 90deg flanged 02

                Gate 14 closed 026 Long radius 90deg threaded 07

                Gate 12 closed 21 Long radius 45deg threaded 02

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                Gate 34 closed 17 Regular 45deg threaded 04

                Swing check forward flow 2

                Swing check backward flow infinity Tees

                Line flow flanged 02

                180deg return bends Line flow threaded 09

                Flanged 02 Branch flow flanged 10

                Threaded 15 Branch flow threaded 20

                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                Square Connection 05 Square Connection 10

                Rounded Connection 02 Rounded Connection 10

                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                bull

                Trapezoidal Open Channel Design Calculation

                Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                Froude number Manning coefficient channel slope

                To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                Register to enable Calculate button

                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                Links on this page Introduction Variables Manning n coefficients Error Messages References

                IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                Variables [] indicates dimensions To calculation

                A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                divided by vertical distance

                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                Oslash = Angle formed by S

                Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                Material Manning n Material Manning n

                Natural Streams Excavated Earth Channels

                Clean and Straight 0030 Clean 0022

                Major Rivers 0035 Gravelly 0025

                Sluggish with Deep Pools 0040 Weedy 0030

                Stony Cobbles 0035

                Metals Floodplains

                Brass 0011 Pasture Farmland 0035

                Cast Iron 0013 Light Brush 0050

                Smooth Steel 0012 Heavy Brush 0075

                Corrugated Metal 0022 Trees 015

                Non-Metals

                Glass 0010 Finished Concrete 0012

                Clay Tile 0014 Unfinished Concrete 0014

                Brickwork 0015 Gravel 0029

                Asphalt 0016 Earth 0025

                Masonry 0025 Planed Wood 0012

                Unplaned Wood 0013

                Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                Waterhammer surge analysis and transient analysis pipe flow modeling software

                Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                View the version 40 New Features List

                Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                Waterhammer surge analysis and transient analysis pipe flow modeling software

                components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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                Details Views Brochure Demo

                copy 2001-2007 Applied Flow Technology All Rights Reserved

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                • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                  • Local Disk
                    • Circular Culvert Design Calculations Software Equations
                        • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                          • Local Disk
                            • Culvert Design Inlet and Outlet Control
                                • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                  • Local Disk
                                    • Design of Circular Water Pipes using Hazen Williams Equation
                                        • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                    • Gradually Varied Flow Calculation Backwater profile
                                                        • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                            • Hydraulic Jump Calculation
                                                                • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                  • Local Disk
                                                                    • Manning Equation
                                                                        • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                            • Non-Circular Open Channel Geometry
                                                                                • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                  • Local Disk
                                                                                    • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                        • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                          • Local Disk
                                                                                            • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                  • Local Disk
                                                                                                    • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                        • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                            • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                  • Local Disk
                                                                                                                    • Waterhammer surge analysis and transient analysis pipe flow modeling software

                  Culvert Design Inlet and Outlet Control

                  Note that instead of using a constant value of 3 Normann (1985) uses a coefficient that varies from 25 to 31 depending on the water depth above the road and whether the road is paved or gravel

                  Variables Back to calculation

                  A=Flow area [ft2]Ac=Flow area in one pipe based on critical depth [ft2]

                  Av=Flow area in one pipe used for computing outlet velocity [ft2]

                  b=Width of channel bottom [ft] Used for computing Yt

                  C1 C2 C3 C4 C5=Constants for inlet control equations See values below

                  D=Diameter of each pipe (culvert) [ft]Eh=Headwater elevation relative to invert of pipe outlet [ft] Pipe outlet invert elevation is defined at 00 ft

                  Ei=Elevation of pipe inlet invert relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

                  Er=Elevation of road (or dam) crest relative to pipe outlet invert [ft] Pipe outlet invert elevation is defined at 00 ft

                  g=Acceleration due to gravity 32174 fts2H=Head loss computed from outlet control equation [ft]Ke=Minor loss coefficient for pipe inlet (used for outlet control equations) See values below

                  Lp=Pipe (culvert) length [ft] If there is more than one culvert they all must have the same length Lp is the length of one of them

                  (not the sum of the lengths)Lw=Weir length [ft] Length of the road (or dam) that water could flow over Lw is the width that the water sees as it flows over

                  the roadnc=Channel Manning n coefficient See values below

                  np=Pipe (culvert) Manning n coefficient See values below

                  N=Number of pipes (culverts) next to each otherP=Wetted perimeter [ft]Qp=Flowrate through each pipe [cfs ft3s]

                  Qr=Flowrate over the road (or dam) [cfs]

                  Qt=Total flowrate [cfs] Sum of flows through pipes plus flow over road

                  Sc=Slope of existing channel [elevation changelength] Longitudinal slope not side slopes

                  Sp=Pipe slope [elevation changelength] Longitudinal slope not side slopes

                  Tc=Top width of flow in one pipe based on critical depth [ft]

                  V=Pipe outlet velocity [fts]Vc=Pipe velocity based on critical depth [fts]

                  Yavg=Average water depth [ft]

                  Yc=Critical water depth [ft]

                  Yf=Fall [ft] Vertical distance that inlet pipe invert is lowered below the existing channel bottom

                  Yh=Headwater depth [ft]

                  Yo=Water outlet depth [ft]

                  Yt=Tailwater depth [ft] Depth of water in existing channel at culvert outlet

                  Yv=Depth used for computing outlet velocity [ft]

                  z1=Left side slope of existing natural channel [horizontalvertical]

                  z2=Right side slope of existing natural channel [horizontalvertical]

                  Values of Coefficients and Manning n Back to calculationManning n values are from Chow (1950) French (1985) Mays (1999) Normann (1985) and Streeter (1998) C1 through C5 and

                  Ke are from Normann (1985)

                  fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (5 of 7)12112007 40331 PM

                  Culvert Design Inlet and Outlet Control

                  Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

                  Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

                  Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

                  Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

                  Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

                  Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

                  Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

                  Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

                  Clean and Straight 0030 Clean 0022

                  Major Rivers 0035 Gravelly 0025

                  Sluggish with Deep Pools 0040 Weedy 0030

                  Stony Cobbles 0035

                  Floodplains

                  Pasture Farmland 0035 Heavy Brush 0075

                  Light Brush 0050 Trees 015

                  Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

                  Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

                  Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

                  the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

                  Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

                  discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

                  side slopesNeed Scgt0 Channel cannot be horizontal

                  Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

                  is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

                  Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

                  fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

                  Culvert Design Inlet and Outlet Control

                  Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

                  Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

                  Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

                  minimum and maximum are too close together to have good axis labels for the graph

                  Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

                  YtgtEr since the equations are only valid for Ytlt=Er

                  References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                  French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                  Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                  LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

                  Design of Circular Water Pipes using Hazen Williams Equation

                  bull

                  Design of Circular Pressurized Water Pipes

                  Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

                  temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                  ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

                  Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

                  LMNO Engineering home page Unit Conversions Page Trouble printing

                  Register to enable Calculate button

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

                  Piping Scenarios

                  fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

                  Design of Circular Water Pipes using Hazen Williams Equation

                  Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

                  fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

                  Design of Circular Water Pipes using Hazen Williams Equation

                  Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

                  Steady State Energy Equation used for this page Back to CalculationsObtained from References

                  Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

                  k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

                  All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

                  Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                  fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

                  Design of Circular Water Pipes using Hazen Williams Equation

                  Material C Material C

                  Asbestos Cement 140 Copper 130-140

                  Brass 130-140 Galvanized iron 120

                  Brick sewer 100 Glass 140

                  Cast-Iron Lead 130-140

                  New unlined 130 Plastic 140-150

                  10 yr old 107-113 Steel

                  20 yr old 89-100 Coal-tar enamel lined 145-150

                  30 yr old 75-90 New unlined 140-150

                  40 yr old 64-83 Riveted 110

                  ConcreteConcrete-lined

                  Steel forms 140 Tin 130

                  Wooden forms 120 Vitrif clay (good condition) 110-140

                  Centrifugally spun 135 Wood stave (avg condition) 120

                  Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                  Fitting Km Fitting Km

                  Valves Elbows

                  Globe fully open 10 Regular 90deg flanged 03

                  Angle fully open 2 Regular 90deg threaded 15

                  Gate fully open 015 Long radius 90deg flanged 02

                  Gate 14 closed 026 Long radius 90deg threaded 07

                  Gate 12 closed 21 Long radius 45deg threaded 02

                  Gate 34 closed 17 Regular 45deg threaded 04

                  Swing check forward flow 2

                  Swing check backward flow infinity Tees

                  Line flow flanged 02

                  180deg return bends Line flow threaded 09

                  Flanged 02 Branch flow flanged 10

                  Threaded 15 Branch flow threaded 20

                  fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                  Design of Circular Water Pipes using Hazen Williams Equation

                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                  Square Connection 05 Square Connection 10

                  Rounded Connection 02 Rounded Connection 10

                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                  copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                  LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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                  DPlot Graphing Software for Scientists and Engineers - Home Page

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                  DPlot Graphing Software for Scientists and Engineers - Home Page

                  or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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                  Gradually Varied Flow Calculation Backwater profile

                  bull

                  Gradually Varied Flow in Trapezoidal Channel

                  Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                  Compute normal and critical depths

                  To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                  LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                  Cross-Section of Trapezoidal Channel

                  Gradually Varied Flow Profiles

                  CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                  middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                  Gradually Varied Flow Calculation Backwater profile

                  Links on this page Equations Variables Manning n coefficients Error messages References

                  Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                  equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                  calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                  The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                  Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                  using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                  References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                  empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                  Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                  Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                  1985) along with the fundamental equations above to solve for Yc

                  Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                  the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                  Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                  critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                  For mild slopes (YngtYc)

                  If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                  water depth gets closer to Yn as the calculation proceeds further and further upstream

                  If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                  Gradually Varied Flow Calculation Backwater profile

                  The water depth gets closer to Yn as the calculation proceeds further and further upstream

                  If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                  is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                  For steep slopes (YcgtYn)

                  If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                  is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                  If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                  water depth gets closer to Yn as the calculation proceeds further and further downstream

                  If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                  water depth gets closer to Yn as the calculation proceeds further and further downstream

                  For critical slopes (Yc=Yn)

                  If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                  water depth gets closer to Yn as the calculation proceeds further and further upstream

                  If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                  water depth gets closer to Yn as the calculation proceeds further and further downstream

                  There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                  Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                  At control section i=1 and Yi=Ys

                  Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                  Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                  Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                  P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                  differential depth increments (this is the basis of the Improved Euler method)

                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                  Gradually Varied Flow Calculation Backwater profile

                  Then repeat the loop by incrementing i

                  The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                  Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                  Ap=Area at Xp [m2]

                  A2=Area for intermediate computation in Improved Euler method [m2]

                  dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                  (dYdX)2=Second depth increment for Improved Euler method [m]

                  B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                  Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                  Epy=Elevation of water surface at Xp [m]

                  F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                  g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                  P2=Second wetted perimeter computed in Improved Euler method [m]

                  Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                  Sf1=First energy slope for Improved Euler method [dimensionless]

                  Sf2=Second energy slope for Improved Euler method [dimensionless]

                  T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                  T2=Second top width computed in Improved Euler method [m]

                  Tp=Top width at Xp [m]

                  V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                  X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                  is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                  Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                  automatically set Xp to Xmax

                  Y=Water depth [m]Yc=Critical depth [m]

                  Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                  Yn=Normal depth [m]

                  Yp=Depth at Xp [m]

                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

                  Gradually Varied Flow Calculation Backwater profile

                  Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                  Y2=Second depth computed in Improved Euler method [m]

                  Z1=One channel side slope (horizontal to vertical ratio) [mm]

                  Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                  Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                  Material Manning n Material Manning n

                  Natural Streams Excavated Earth Channels

                  Clean and Straight 0030 Clean 0022

                  Major Rivers 0035 Gravelly 0025

                  Sluggish with Deep Pools 0040 Weedy 0030

                  Stony Cobbles 0035

                  Metals Floodplains

                  Brass 0011 Pasture Farmland 0035

                  Cast Iron 0013 Light Brush 0050

                  Smooth Steel 0012 Heavy Brush 0075

                  Corrugated Metal 0022 Trees 015

                  Non-Metals

                  Glass 0010 Finished Concrete 0012

                  Clay Tile 0014 Unfinished Concrete 0014

                  Brickwork 0015 Gravel 0029

                  Asphalt 0016 Earth 0025

                  Masonry 0025 Planed Wood 0012

                  Unplaned Wood 0013

                  Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                  20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                  Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                  Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                  is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                  References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                  Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                  Gradually Varied Flow Calculation Backwater profile

                  Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                  French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                  Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                  Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                  Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                  Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                  copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                  LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                  Hydraulic Jump Calculation

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                  Hydraulic Jump in Horizontal Rectangular Channel

                  Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                  jump length and energy loss

                  To LMNO Engineering home page (all calculations) Related open channel calculations

                  Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                  Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                  Hydraulic Jump Calculation

                  Register to enable Calculate button

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  Equations

                  Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                  V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                  L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                  where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                  Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                  What is a Hydraulic Jump

                  A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                  According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                  oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                  occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                  Hydraulic Jump Calculation

                  MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                  Need F1 gt1 Upstream flow must be supercritical

                  ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                  copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                  LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                  Manning Equation

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                  Mannings Equation Calculator Software The open channel flow software website

                  LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                  Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                  and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                  The product AP is also known as the hydraulic radius Rh

                  fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                  Non-Circular Open Channel Geometry

                  bull

                  Geometric Calculations for Non-Circular Partially Filled Channels

                  The open channel flow calculations software website

                  Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                  Equations (note that R=AP)

                  fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                  bull

                  Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                  losses

                  Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                  pipe Dont have to use all the pipes or nodes

                  To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                  Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                  Register to fully enable Calculate button

                  Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                  IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                  Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                  The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                  Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                  Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                  1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                  Pipe flows are adjusted iteratively using the following equation

                  until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                  Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                  Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                  Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                  where log is base 10 logarithm and ln is natural logarithm Variable definitions

                  Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                  Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                  Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                  Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                  The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                  ApplicationsThe pipe network calculation has many applications Two examples will be provided

                  1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                  pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                  2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                  Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                  Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                  Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                  A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                  n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                  Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                  Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                  References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                  Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                  LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  bull

                  Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                  Weisbach - Moody friction losses)

                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                  (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                  Parabolic shaped pump curve is formed from the two points

                  ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                  curve Hazen-Williams with pump curve

                  Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                  Register to enable Calculate button

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                  IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                  A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                  For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                  (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                  Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                  calculation will look like

                  The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                  Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                  Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                  is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                  defined for liquids

                  Variables Units F=force L=length P=pressure T=time Back to Calculations

                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                  A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                  hf = Major losses for entire pipe [L] Also known as friction losses

                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                  hm = Minor losses for entire pipe [L]

                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                  K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                  for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                  P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                  location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                  zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                  this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                  v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                  Fitting K Fitting K

                  Valves Elbows

                  Globe fully open 10 Regular 90deg flanged 03

                  Angle fully open 2 Regular 90deg threaded 15

                  Gate fully open 015 Long radius 90deg flanged 02

                  Gate 14 closed 026 Long radius 90deg threaded 07

                  Gate 12 closed 21 Long radius 45deg threaded 02

                  Gate 34 closed 17 Regular 45deg threaded 04

                  Swing check forward flow 2

                  Swing check backward flow infinity Tees

                  Line flow flanged 02

                  180deg return bends Line flow threaded 09

                  Flanged 02 Branch flow flanged 10

                  Threaded 15 Branch flow threaded 20

                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  Square Connection 05 Square Connection 10

                  Rounded Connection 02 Rounded Connection 10

                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                  Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                  The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                  Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                  the pipe or K for the suction pipe was entered as greater than K for the entire system

                  Other messagesK must be gt=1 If Q known Solve for D and V

                  3=0 then K must be gt 1 in order to solve

                  Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                  reservoirs are defined to be at zero pressure thus zero pressure difference

                  Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                  Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                  References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                  Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                  Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                  Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                  Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                  White F M 1979 Fluid Mechanics McGraw-Hill Inc

                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                  LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  bull

                  Circular Pressurized Water Pipes with Pump Curve

                  (Hazen Williams)

                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                  (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                  temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                  ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                  curve Darcy-Weisbach with pump curve

                  Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                  Register to enable Calculate button

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                  IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                  function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                  manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                  Equations and Methodology Back to Calculations

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                  calculation will look like

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                  Variables Units L=length P=pressure T=time Back to Calculations

                  A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                  g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                  hf = Major losses for entire pipe [L]

                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                  hm = Minor losses for entire pipe [L]

                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                  k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                  L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                  program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                  location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                  zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                  this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                  Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                  available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                  and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                  Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                  Material C Material C

                  Asbestos Cement 140 Copper 130-140

                  Brass 130-140 Galvanized iron 120

                  Brick sewer 100 Glass 140

                  Cast-Iron Lead 130-140

                  New unlined 130 Plastic 140-150

                  10 yr old 107-113 Steel

                  20 yr old 89-100 Coal-tar enamel lined 145-150

                  30 yr old 75-90 New unlined 140-150

                  40 yr old 64-83 Riveted 110

                  ConcreteConcrete-lined

                  Steel forms 140 Tin 130

                  Wooden forms 120 Vitrif clay (good condition) 110-140

                  Centrifugally spun 135 Wood stave (avg condition) 120

                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                  Fitting K Fitting K

                  Valves Elbows

                  Globe fully open 10 Regular 90deg flanged 03

                  Angle fully open 2 Regular 90deg threaded 15

                  Gate fully open 015 Long radius 90deg flanged 02

                  Gate 14 closed 026 Long radius 90deg threaded 07

                  Gate 12 closed 21 Long radius 45deg threaded 02

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  Gate 34 closed 17 Regular 45deg threaded 04

                  Swing check forward flow 2

                  Swing check backward flow infinity Tees

                  Line flow flanged 02

                  180deg return bends Line flow threaded 09

                  Flanged 02 Branch flow flanged 10

                  Threaded 15 Branch flow threaded 20

                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                  Square Connection 05 Square Connection 10

                  Rounded Connection 02 Rounded Connection 10

                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                  Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                  entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                  One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                  entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                  P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                  to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                  the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                  and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                  pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                  result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                  be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                  lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                  LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                  bull

                  Trapezoidal Open Channel Design Calculation

                  Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                  Froude number Manning coefficient channel slope

                  To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                  Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                  Register to enable Calculate button

                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                  Links on this page Introduction Variables Manning n coefficients Error Messages References

                  IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                  beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                  The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                  In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                  Variables [] indicates dimensions To calculation

                  A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                  divided by vertical distance

                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                  Oslash = Angle formed by S

                  Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                  Material Manning n Material Manning n

                  Natural Streams Excavated Earth Channels

                  Clean and Straight 0030 Clean 0022

                  Major Rivers 0035 Gravelly 0025

                  Sluggish with Deep Pools 0040 Weedy 0030

                  Stony Cobbles 0035

                  Metals Floodplains

                  Brass 0011 Pasture Farmland 0035

                  Cast Iron 0013 Light Brush 0050

                  Smooth Steel 0012 Heavy Brush 0075

                  Corrugated Metal 0022 Trees 015

                  Non-Metals

                  Glass 0010 Finished Concrete 0012

                  Clay Tile 0014 Unfinished Concrete 0014

                  Brickwork 0015 Gravel 0029

                  Asphalt 0016 Earth 0025

                  Masonry 0025 Planed Wood 0012

                  Unplaned Wood 0013

                  Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                  Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                  Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                  Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                  The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                  cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                  simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                  The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                  References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                  a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                  c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                  e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                  Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                  French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                  d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                  Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                  b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                  7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                  Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                  Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                  View the version 40 New Features List

                  Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                  AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                  fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                  components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                  From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                  View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                  Learn More About AFT Impulse 40

                  Details Views Brochure Demo

                  copy 2001-2007 Applied Flow Technology All Rights Reserved

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                  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                    • Local Disk
                      • Circular Culvert Design Calculations Software Equations
                          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                            • Local Disk
                              • Culvert Design Inlet and Outlet Control
                                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                      • Design of Circular Water Pipes using Hazen Williams Equation
                                          • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                              • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                  • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                      • Gradually Varied Flow Calculation Backwater profile
                                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                              • Hydraulic Jump Calculation
                                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                      • Manning Equation
                                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                              • Non-Circular Open Channel Geometry
                                                                                  • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                  • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                    • Local Disk
                                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

                    Culvert Design Inlet and Outlet Control

                    Pipe material and inlet type Manning n C1 C2 C3 C4 C5 Ke

                    Concrete Square edge inlet with headwall 0013 00098 20 -05 00398 067 05

                    Concrete Groove end inlet with headwall 0013 00078 20 -05 00292 074 02

                    Concrete Groove end projecting at inlet 0013 00045 20 -05 00317 069 02

                    Corrugated metal (CMP) Headwall at inlet 0022 00078 20 -05 00379 069 05

                    Corrugated metal (CMP) Mitered to slope at inlet 0022 00210 133 07 00463 075 07

                    Corrugated metal (CMP) Projecting at inlet 0022 00340 150 -05 00553 054 09

                    Channel Material Manning n Material Manning nNatural Streams Excavated Earth Channels

                    Clean and Straight 0030 Clean 0022

                    Major Rivers 0035 Gravelly 0025

                    Sluggish with Deep Pools 0040 Weedy 0030

                    Stony Cobbles 0035

                    Floodplains

                    Pasture Farmland 0035 Heavy Brush 0075

                    Light Brush 0050 Trees 015

                    Error Messages and Validity Back to calculationInput checks in top half of calculation If one of these messages appears the calculation and graphing is haltedNeed 0lt=Qtlt10000 m3s Total flow cannot be negative or must be less than 10000 m3s

                    Need 0ltNlt1001 Must have at least one pipe but no more than 1000 pipesNeed 0ltDlt100 m Pipe diameter must be positive and less than 100 mNeed 0ltLplt10000 m Pipe length must be positive and less than 10000 mNeed 0ltPipe nlt005 Pipe Manning n must be positive and less than 005Need YtltEr Tailwater depth cannot be higher than the road crest

                    Need Ei+DltEr Upstream pipe invert plus culvert diameter cannot exceed road crest elevation If Ei+D is greater than Er then

                    the top of the culvert is pushing through the road which is unacceptableNeed 0ltLwlt10000 m Weir length of road (or dam) must be positive and less than 10000 m

                    Need Ytlt10000 m Tailwater depth must be less than 10000 m Negative values are acceptable Negatives simulate culverts

                    discharging to a lower channelNeed Sclt05 Channel bottom slope cannot exceed 05 mm (vertical to horizontal ratio) This is the longitudinal slope not the

                    side slopesNeed Scgt0 Channel cannot be horizontal

                    Need 0ltChan nlt05 Channel Manning n must be positive and less than 05Need 0ltblt10000 m Channel bottom width must be positive and less than 10000 mNeed 0ltz1lt10000 Need 0ltz2lt10000 Channel side slopes can be neither exactly vertical (z=0) nor nearly flat (zgt10000) z

                    is defined as horizontal to vertical ratioNeed 1e-7ltSplt05 Pipe slope must be between these limits

                    Input checks for graph If one of these messages appears the graph will not proceed Note that if any value is out of range in the upper portion of the calculation a graph will not be shownNeed min Qtgt=0 Minimum total flow for graph was entered as a negative number

                    fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (6 of 7)12112007 40331 PM

                    Culvert Design Inlet and Outlet Control

                    Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

                    Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

                    Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

                    minimum and maximum are too close together to have good axis labels for the graph

                    Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

                    YtgtEr since the equations are only valid for Ytlt=Er

                    References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                    French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                    Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                    LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

                    Design of Circular Water Pipes using Hazen Williams Equation

                    bull

                    Design of Circular Pressurized Water Pipes

                    Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

                    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                    ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

                    Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

                    LMNO Engineering home page Unit Conversions Page Trouble printing

                    Register to enable Calculate button

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

                    Piping Scenarios

                    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

                    Design of Circular Water Pipes using Hazen Williams Equation

                    Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

                    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

                    Design of Circular Water Pipes using Hazen Williams Equation

                    Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

                    Steady State Energy Equation used for this page Back to CalculationsObtained from References

                    Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

                    k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

                    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

                    Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

                    Design of Circular Water Pipes using Hazen Williams Equation

                    Material C Material C

                    Asbestos Cement 140 Copper 130-140

                    Brass 130-140 Galvanized iron 120

                    Brick sewer 100 Glass 140

                    Cast-Iron Lead 130-140

                    New unlined 130 Plastic 140-150

                    10 yr old 107-113 Steel

                    20 yr old 89-100 Coal-tar enamel lined 145-150

                    30 yr old 75-90 New unlined 140-150

                    40 yr old 64-83 Riveted 110

                    ConcreteConcrete-lined

                    Steel forms 140 Tin 130

                    Wooden forms 120 Vitrif clay (good condition) 110-140

                    Centrifugally spun 135 Wood stave (avg condition) 120

                    Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                    Fitting Km Fitting Km

                    Valves Elbows

                    Globe fully open 10 Regular 90deg flanged 03

                    Angle fully open 2 Regular 90deg threaded 15

                    Gate fully open 015 Long radius 90deg flanged 02

                    Gate 14 closed 026 Long radius 90deg threaded 07

                    Gate 12 closed 21 Long radius 45deg threaded 02

                    Gate 34 closed 17 Regular 45deg threaded 04

                    Swing check forward flow 2

                    Swing check backward flow infinity Tees

                    Line flow flanged 02

                    180deg return bends Line flow threaded 09

                    Flanged 02 Branch flow flanged 10

                    Threaded 15 Branch flow threaded 20

                    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                    Design of Circular Water Pipes using Hazen Williams Equation

                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                    Square Connection 05 Square Connection 10

                    Rounded Connection 02 Rounded Connection 10

                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                    copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                    LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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                    Compatible with Windowsreg 95 98 2000 ME NT 2003 XP and Vista

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                    DPlot Graphing Software for Scientists and Engineers - Home Page

                    Current Version (9 December 2007)The latest release version of DPlot is 2149 Check the Revision History page for a list of recent changes Licensed users should sign up for the mailing list to receive instructions for downloading the free upgrade or select Check for Updates on the Help menu within DPlot

                    NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

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                    DPlot Graphing Software for Scientists and Engineers - Home Page

                    or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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                    Gradually Varied Flow Calculation Backwater profile

                    bull

                    Gradually Varied Flow in Trapezoidal Channel

                    Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                    Compute normal and critical depths

                    To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                    LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                    Cross-Section of Trapezoidal Channel

                    Gradually Varied Flow Profiles

                    CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                    middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                    Gradually Varied Flow Calculation Backwater profile

                    Links on this page Equations Variables Manning n coefficients Error messages References

                    Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                    equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                    calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                    The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                    Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                    using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                    References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                    empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                    Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                    Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                    1985) along with the fundamental equations above to solve for Yc

                    Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                    the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                    Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                    critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                    For mild slopes (YngtYc)

                    If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                    water depth gets closer to Yn as the calculation proceeds further and further upstream

                    If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                    Gradually Varied Flow Calculation Backwater profile

                    The water depth gets closer to Yn as the calculation proceeds further and further upstream

                    If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                    is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                    For steep slopes (YcgtYn)

                    If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                    is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                    If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                    water depth gets closer to Yn as the calculation proceeds further and further downstream

                    If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                    water depth gets closer to Yn as the calculation proceeds further and further downstream

                    For critical slopes (Yc=Yn)

                    If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                    water depth gets closer to Yn as the calculation proceeds further and further upstream

                    If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                    water depth gets closer to Yn as the calculation proceeds further and further downstream

                    There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                    Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                    At control section i=1 and Yi=Ys

                    Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                    Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                    Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                    P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                    differential depth increments (this is the basis of the Improved Euler method)

                    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                    Gradually Varied Flow Calculation Backwater profile

                    Then repeat the loop by incrementing i

                    The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                    Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                    Ap=Area at Xp [m2]

                    A2=Area for intermediate computation in Improved Euler method [m2]

                    dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                    (dYdX)2=Second depth increment for Improved Euler method [m]

                    B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                    Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                    Epy=Elevation of water surface at Xp [m]

                    F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                    g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                    P2=Second wetted perimeter computed in Improved Euler method [m]

                    Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                    Sf1=First energy slope for Improved Euler method [dimensionless]

                    Sf2=Second energy slope for Improved Euler method [dimensionless]

                    T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                    T2=Second top width computed in Improved Euler method [m]

                    Tp=Top width at Xp [m]

                    V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                    X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                    is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                    Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                    automatically set Xp to Xmax

                    Y=Water depth [m]Yc=Critical depth [m]

                    Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                    Yn=Normal depth [m]

                    Yp=Depth at Xp [m]

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                    Gradually Varied Flow Calculation Backwater profile

                    Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                    Y2=Second depth computed in Improved Euler method [m]

                    Z1=One channel side slope (horizontal to vertical ratio) [mm]

                    Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                    Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                    Material Manning n Material Manning n

                    Natural Streams Excavated Earth Channels

                    Clean and Straight 0030 Clean 0022

                    Major Rivers 0035 Gravelly 0025

                    Sluggish with Deep Pools 0040 Weedy 0030

                    Stony Cobbles 0035

                    Metals Floodplains

                    Brass 0011 Pasture Farmland 0035

                    Cast Iron 0013 Light Brush 0050

                    Smooth Steel 0012 Heavy Brush 0075

                    Corrugated Metal 0022 Trees 015

                    Non-Metals

                    Glass 0010 Finished Concrete 0012

                    Clay Tile 0014 Unfinished Concrete 0014

                    Brickwork 0015 Gravel 0029

                    Asphalt 0016 Earth 0025

                    Masonry 0025 Planed Wood 0012

                    Unplaned Wood 0013

                    Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                    20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                    Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                    Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                    is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                    References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                    Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                    Gradually Varied Flow Calculation Backwater profile

                    Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                    French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                    Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                    Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                    Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                    Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                    copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                    LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                    Hydraulic Jump Calculation

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                    Hydraulic Jump in Horizontal Rectangular Channel

                    Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                    jump length and energy loss

                    To LMNO Engineering home page (all calculations) Related open channel calculations

                    Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                    Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                    fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                    Hydraulic Jump Calculation

                    Register to enable Calculate button

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    Equations

                    Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                    V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                    L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                    where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                    Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                    What is a Hydraulic Jump

                    A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                    According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                    oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                    occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                    Hydraulic Jump Calculation

                    MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                    Need F1 gt1 Upstream flow must be supercritical

                    ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                    copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                    LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                    Manning Equation

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                    Mannings Equation Calculator Software The open channel flow software website

                    LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                    Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                    and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                    The product AP is also known as the hydraulic radius Rh

                    fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                    Non-Circular Open Channel Geometry

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                    Geometric Calculations for Non-Circular Partially Filled Channels

                    The open channel flow calculations software website

                    Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                    Equations (note that R=AP)

                    fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                    bull

                    Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                    losses

                    Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                    pipe Dont have to use all the pipes or nodes

                    To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                    Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                    Register to fully enable Calculate button

                    Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                    IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                    Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                    The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                    Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                    Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                    1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                    Pipe flows are adjusted iteratively using the following equation

                    until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                    Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                    Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                    Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                    where log is base 10 logarithm and ln is natural logarithm Variable definitions

                    Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                    Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                    Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                    Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                    The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                    ApplicationsThe pipe network calculation has many applications Two examples will be provided

                    1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                    pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                    2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                    Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                    Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                    Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                    A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                    n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                    Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                    Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                    References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                    Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                    LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    bull

                    Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                    Weisbach - Moody friction losses)

                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                    (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                    Parabolic shaped pump curve is formed from the two points

                    ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                    curve Hazen-Williams with pump curve

                    Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                    Register to enable Calculate button

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                    IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                    A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                    For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                    (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                    Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                    calculation will look like

                    The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                    Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                    Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                    is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                    defined for liquids

                    Variables Units F=force L=length P=pressure T=time Back to Calculations

                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                    A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                    hf = Major losses for entire pipe [L] Also known as friction losses

                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                    hm = Minor losses for entire pipe [L]

                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                    K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                    for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                    P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                    location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                    zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                    this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                    v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                    Fitting K Fitting K

                    Valves Elbows

                    Globe fully open 10 Regular 90deg flanged 03

                    Angle fully open 2 Regular 90deg threaded 15

                    Gate fully open 015 Long radius 90deg flanged 02

                    Gate 14 closed 026 Long radius 90deg threaded 07

                    Gate 12 closed 21 Long radius 45deg threaded 02

                    Gate 34 closed 17 Regular 45deg threaded 04

                    Swing check forward flow 2

                    Swing check backward flow infinity Tees

                    Line flow flanged 02

                    180deg return bends Line flow threaded 09

                    Flanged 02 Branch flow flanged 10

                    Threaded 15 Branch flow threaded 20

                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    Square Connection 05 Square Connection 10

                    Rounded Connection 02 Rounded Connection 10

                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                    Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                    The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                    Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                    the pipe or K for the suction pipe was entered as greater than K for the entire system

                    Other messagesK must be gt=1 If Q known Solve for D and V

                    3=0 then K must be gt 1 in order to solve

                    Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                    reservoirs are defined to be at zero pressure thus zero pressure difference

                    Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                    Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                    References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                    Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                    Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                    Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                    Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                    White F M 1979 Fluid Mechanics McGraw-Hill Inc

                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                    LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    bull

                    Circular Pressurized Water Pipes with Pump Curve

                    (Hazen Williams)

                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                    (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                    ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                    curve Darcy-Weisbach with pump curve

                    Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                    Register to enable Calculate button

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                    IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                    function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                    manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                    Equations and Methodology Back to Calculations

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                    calculation will look like

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                    Variables Units L=length P=pressure T=time Back to Calculations

                    A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                    g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                    hf = Major losses for entire pipe [L]

                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                    hm = Minor losses for entire pipe [L]

                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                    k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                    L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                    program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                    location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                    zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                    this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                    Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                    available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                    and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                    Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                    Material C Material C

                    Asbestos Cement 140 Copper 130-140

                    Brass 130-140 Galvanized iron 120

                    Brick sewer 100 Glass 140

                    Cast-Iron Lead 130-140

                    New unlined 130 Plastic 140-150

                    10 yr old 107-113 Steel

                    20 yr old 89-100 Coal-tar enamel lined 145-150

                    30 yr old 75-90 New unlined 140-150

                    40 yr old 64-83 Riveted 110

                    ConcreteConcrete-lined

                    Steel forms 140 Tin 130

                    Wooden forms 120 Vitrif clay (good condition) 110-140

                    Centrifugally spun 135 Wood stave (avg condition) 120

                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                    Fitting K Fitting K

                    Valves Elbows

                    Globe fully open 10 Regular 90deg flanged 03

                    Angle fully open 2 Regular 90deg threaded 15

                    Gate fully open 015 Long radius 90deg flanged 02

                    Gate 14 closed 026 Long radius 90deg threaded 07

                    Gate 12 closed 21 Long radius 45deg threaded 02

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    Gate 34 closed 17 Regular 45deg threaded 04

                    Swing check forward flow 2

                    Swing check backward flow infinity Tees

                    Line flow flanged 02

                    180deg return bends Line flow threaded 09

                    Flanged 02 Branch flow flanged 10

                    Threaded 15 Branch flow threaded 20

                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                    Square Connection 05 Square Connection 10

                    Rounded Connection 02 Rounded Connection 10

                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                    Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                    entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                    One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                    entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                    P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                    to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                    the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                    and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                    pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                    result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                    be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                    lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                    LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                    bull

                    Trapezoidal Open Channel Design Calculation

                    Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                    Froude number Manning coefficient channel slope

                    To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                    Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                    Register to enable Calculate button

                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                    Links on this page Introduction Variables Manning n coefficients Error Messages References

                    IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                    beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                    The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                    Variables [] indicates dimensions To calculation

                    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                    divided by vertical distance

                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                    Oslash = Angle formed by S

                    Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                    Material Manning n Material Manning n

                    Natural Streams Excavated Earth Channels

                    Clean and Straight 0030 Clean 0022

                    Major Rivers 0035 Gravelly 0025

                    Sluggish with Deep Pools 0040 Weedy 0030

                    Stony Cobbles 0035

                    Metals Floodplains

                    Brass 0011 Pasture Farmland 0035

                    Cast Iron 0013 Light Brush 0050

                    Smooth Steel 0012 Heavy Brush 0075

                    Corrugated Metal 0022 Trees 015

                    Non-Metals

                    Glass 0010 Finished Concrete 0012

                    Clay Tile 0014 Unfinished Concrete 0014

                    Brickwork 0015 Gravel 0029

                    Asphalt 0016 Earth 0025

                    Masonry 0025 Planed Wood 0012

                    Unplaned Wood 0013

                    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                    Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                    The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                    cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                    simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                    The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                    References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                    a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                    Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                    French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                    Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                    7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                    Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                    View the version 40 New Features List

                    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                    Learn More About AFT Impulse 40

                    Details Views Brochure Demo

                    copy 2001-2007 Applied Flow Technology All Rights Reserved

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                    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                      • Local Disk
                        • Circular Culvert Design Calculations Software Equations
                            • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                              • Local Disk
                                • Culvert Design Inlet and Outlet Control
                                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                      • Local Disk
                                        • Design of Circular Water Pipes using Hazen Williams Equation
                                            • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                              • Local Disk
                                                • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                    • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                        • Gradually Varied Flow Calculation Backwater profile
                                                            • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                • Hydraulic Jump Calculation
                                                                    • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                        • Manning Equation
                                                                            • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                • Non-Circular Open Channel Geometry
                                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                      • Local Disk
                                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                              • Local Disk
                                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                    • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                            • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                      • Local Disk
                                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

                      Culvert Design Inlet and Outlet Control

                      Max Qtgt10000 m3s Maximum total flow for graph cannot exceed 10000 m3s

                      Min must be lt Max Minimum Qt entered for graph must be less than maximum Qt entered for graph

                      Need MinMaxlt099 Minimum Qt entered for graph must be less than 099 times maximum Qt entered for graph Otherwise the

                      minimum and maximum are too close together to have good axis labels for the graph

                      Run-time errors The following message may be generated by the graphing portion of the calculationYtgtEr for some Qt Tailwater depth exceeds road (or dam) crest for large values of Qt Yh cannot be computed or graphed when

                      YtgtEr since the equations are only valid for Ytlt=Er

                      References Back to calculationChow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                      French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                      Normann J M 1985 Hydraulic design of highway culverts HDS-5 (Hydraulic Design Series 5) FHWA-IP-85-15 NTIS publication PB86196961 Obtainable at httpwwwntisgov

                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                      LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsCulvert20Design_20Inlet20and20Outlet20Controlhtm (7 of 7)12112007 40331 PM

                      Design of Circular Water Pipes using Hazen Williams Equation

                      bull

                      Design of Circular Pressurized Water Pipes

                      Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

                      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                      ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

                      Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

                      LMNO Engineering home page Unit Conversions Page Trouble printing

                      Register to enable Calculate button

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

                      Piping Scenarios

                      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

                      Design of Circular Water Pipes using Hazen Williams Equation

                      Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

                      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

                      Design of Circular Water Pipes using Hazen Williams Equation

                      Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

                      Steady State Energy Equation used for this page Back to CalculationsObtained from References

                      Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

                      k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

                      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

                      Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

                      Design of Circular Water Pipes using Hazen Williams Equation

                      Material C Material C

                      Asbestos Cement 140 Copper 130-140

                      Brass 130-140 Galvanized iron 120

                      Brick sewer 100 Glass 140

                      Cast-Iron Lead 130-140

                      New unlined 130 Plastic 140-150

                      10 yr old 107-113 Steel

                      20 yr old 89-100 Coal-tar enamel lined 145-150

                      30 yr old 75-90 New unlined 140-150

                      40 yr old 64-83 Riveted 110

                      ConcreteConcrete-lined

                      Steel forms 140 Tin 130

                      Wooden forms 120 Vitrif clay (good condition) 110-140

                      Centrifugally spun 135 Wood stave (avg condition) 120

                      Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                      Fitting Km Fitting Km

                      Valves Elbows

                      Globe fully open 10 Regular 90deg flanged 03

                      Angle fully open 2 Regular 90deg threaded 15

                      Gate fully open 015 Long radius 90deg flanged 02

                      Gate 14 closed 026 Long radius 90deg threaded 07

                      Gate 12 closed 21 Long radius 45deg threaded 02

                      Gate 34 closed 17 Regular 45deg threaded 04

                      Swing check forward flow 2

                      Swing check backward flow infinity Tees

                      Line flow flanged 02

                      180deg return bends Line flow threaded 09

                      Flanged 02 Branch flow flanged 10

                      Threaded 15 Branch flow threaded 20

                      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                      Design of Circular Water Pipes using Hazen Williams Equation

                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                      Square Connection 05 Square Connection 10

                      Rounded Connection 02 Rounded Connection 10

                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                      copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                      LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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                      Compatible with Windowsreg 95 98 2000 ME NT 2003 XP and Vista

                      DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

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                      DPlot Graphing Software for Scientists and Engineers - Home Page

                      Current Version (9 December 2007)The latest release version of DPlot is 2149 Check the Revision History page for a list of recent changes Licensed users should sign up for the mailing list to receive instructions for downloading the free upgrade or select Check for Updates on the Help menu within DPlot

                      NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

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                      Other ProductsIf you produce graphs with DPlot and would like to distribute them to others youll want to take a look at DPlot Viewer This is a free application that may be distributed to others without charge DPlot Viewer will display andor print any graph produced by DPlot

                      Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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                      DPlot Graphing Software for Scientists and Engineers - Home Page

                      or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

                      DPlot AccessoriesDo you need a new coffee cup mouse pad or golf shirt Of course you do Visit our online Accessories Store today

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                      fileE|engineeringhydraulicsDPlot20Graphing220Scientists20and20Engineers20-20Home20Pagehtm (3 of 3)12112007 40513 PM

                      Gradually Varied Flow Calculation Backwater profile

                      bull

                      Gradually Varied Flow in Trapezoidal Channel

                      Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                      Compute normal and critical depths

                      To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                      LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                      Cross-Section of Trapezoidal Channel

                      Gradually Varied Flow Profiles

                      CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                      middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                      Gradually Varied Flow Calculation Backwater profile

                      Links on this page Equations Variables Manning n coefficients Error messages References

                      Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                      equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                      calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                      The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                      Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                      using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                      References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                      empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                      Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                      Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                      1985) along with the fundamental equations above to solve for Yc

                      Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                      the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                      Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                      critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                      For mild slopes (YngtYc)

                      If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                      water depth gets closer to Yn as the calculation proceeds further and further upstream

                      If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                      Gradually Varied Flow Calculation Backwater profile

                      The water depth gets closer to Yn as the calculation proceeds further and further upstream

                      If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                      is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                      For steep slopes (YcgtYn)

                      If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                      is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                      If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                      water depth gets closer to Yn as the calculation proceeds further and further downstream

                      If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                      water depth gets closer to Yn as the calculation proceeds further and further downstream

                      For critical slopes (Yc=Yn)

                      If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                      water depth gets closer to Yn as the calculation proceeds further and further upstream

                      If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                      water depth gets closer to Yn as the calculation proceeds further and further downstream

                      There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                      Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                      At control section i=1 and Yi=Ys

                      Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                      Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                      Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                      P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                      differential depth increments (this is the basis of the Improved Euler method)

                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                      Gradually Varied Flow Calculation Backwater profile

                      Then repeat the loop by incrementing i

                      The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                      Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                      Ap=Area at Xp [m2]

                      A2=Area for intermediate computation in Improved Euler method [m2]

                      dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                      (dYdX)2=Second depth increment for Improved Euler method [m]

                      B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                      Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                      Epy=Elevation of water surface at Xp [m]

                      F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                      g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                      P2=Second wetted perimeter computed in Improved Euler method [m]

                      Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                      Sf1=First energy slope for Improved Euler method [dimensionless]

                      Sf2=Second energy slope for Improved Euler method [dimensionless]

                      T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                      T2=Second top width computed in Improved Euler method [m]

                      Tp=Top width at Xp [m]

                      V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                      X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                      is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                      Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                      automatically set Xp to Xmax

                      Y=Water depth [m]Yc=Critical depth [m]

                      Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                      Yn=Normal depth [m]

                      Yp=Depth at Xp [m]

                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

                      Gradually Varied Flow Calculation Backwater profile

                      Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                      Y2=Second depth computed in Improved Euler method [m]

                      Z1=One channel side slope (horizontal to vertical ratio) [mm]

                      Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                      Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                      Material Manning n Material Manning n

                      Natural Streams Excavated Earth Channels

                      Clean and Straight 0030 Clean 0022

                      Major Rivers 0035 Gravelly 0025

                      Sluggish with Deep Pools 0040 Weedy 0030

                      Stony Cobbles 0035

                      Metals Floodplains

                      Brass 0011 Pasture Farmland 0035

                      Cast Iron 0013 Light Brush 0050

                      Smooth Steel 0012 Heavy Brush 0075

                      Corrugated Metal 0022 Trees 015

                      Non-Metals

                      Glass 0010 Finished Concrete 0012

                      Clay Tile 0014 Unfinished Concrete 0014

                      Brickwork 0015 Gravel 0029

                      Asphalt 0016 Earth 0025

                      Masonry 0025 Planed Wood 0012

                      Unplaned Wood 0013

                      Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                      20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                      Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                      Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                      is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                      References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                      Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                      Gradually Varied Flow Calculation Backwater profile

                      Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                      French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                      Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                      Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                      Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                      Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                      copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                      LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                      Hydraulic Jump Calculation

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                      Hydraulic Jump in Horizontal Rectangular Channel

                      Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                      jump length and energy loss

                      To LMNO Engineering home page (all calculations) Related open channel calculations

                      Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                      Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                      fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                      Hydraulic Jump Calculation

                      Register to enable Calculate button

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      Equations

                      Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                      V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                      L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                      where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                      Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                      What is a Hydraulic Jump

                      A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                      According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                      oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                      occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                      Hydraulic Jump Calculation

                      MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                      Need F1 gt1 Upstream flow must be supercritical

                      ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                      copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                      LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                      Manning Equation

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                      Mannings Equation Calculator Software The open channel flow software website

                      LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                      Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                      and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                      The product AP is also known as the hydraulic radius Rh

                      fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                      Non-Circular Open Channel Geometry

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                      Geometric Calculations for Non-Circular Partially Filled Channels

                      The open channel flow calculations software website

                      Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                      Equations (note that R=AP)

                      fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                      Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                      losses

                      Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                      pipe Dont have to use all the pipes or nodes

                      To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                      Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                      Register to fully enable Calculate button

                      Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                      IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                      Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                      The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                      Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                      Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                      1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                      Pipe flows are adjusted iteratively using the following equation

                      until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                      Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                      Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                      Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                      where log is base 10 logarithm and ln is natural logarithm Variable definitions

                      Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                      Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                      Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                      Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                      The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                      ApplicationsThe pipe network calculation has many applications Two examples will be provided

                      1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                      pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                      2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                      Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                      Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                      Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                      A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                      n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                      Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                      Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                      References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                      Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                      LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                      Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                      Weisbach - Moody friction losses)

                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                      (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                      Parabolic shaped pump curve is formed from the two points

                      ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                      curve Hazen-Williams with pump curve

                      Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                      Register to enable Calculate button

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                      IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                      A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                      For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                      (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                      Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                      Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                      calculation will look like

                      The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                      Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                      Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                      is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                      defined for liquids

                      Variables Units F=force L=length P=pressure T=time Back to Calculations

                      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                      is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                      A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                      hf = Major losses for entire pipe [L] Also known as friction losses

                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                      hm = Minor losses for entire pipe [L]

                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                      K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                      for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                      P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                      location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                      zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                      V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                      this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                      v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                      Fitting K Fitting K

                      Valves Elbows

                      Globe fully open 10 Regular 90deg flanged 03

                      Angle fully open 2 Regular 90deg threaded 15

                      Gate fully open 015 Long radius 90deg flanged 02

                      Gate 14 closed 026 Long radius 90deg threaded 07

                      Gate 12 closed 21 Long radius 45deg threaded 02

                      Gate 34 closed 17 Regular 45deg threaded 04

                      Swing check forward flow 2

                      Swing check backward flow infinity Tees

                      Line flow flanged 02

                      180deg return bends Line flow threaded 09

                      Flanged 02 Branch flow flanged 10

                      Threaded 15 Branch flow threaded 20

                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                      Square Connection 05 Square Connection 10

                      Rounded Connection 02 Rounded Connection 10

                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                      Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                      The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                      Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                      the pipe or K for the suction pipe was entered as greater than K for the entire system

                      Other messagesK must be gt=1 If Q known Solve for D and V

                      3=0 then K must be gt 1 in order to solve

                      Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                      reservoirs are defined to be at zero pressure thus zero pressure difference

                      Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                      Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                      References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                      Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                      Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                      Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                      Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                      White F M 1979 Fluid Mechanics McGraw-Hill Inc

                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                      LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      bull

                      Circular Pressurized Water Pipes with Pump Curve

                      (Hazen Williams)

                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                      (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                      ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                      curve Darcy-Weisbach with pump curve

                      Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                      Register to enable Calculate button

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                      IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                      function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                      manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                      Equations and Methodology Back to Calculations

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                      calculation will look like

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                      Variables Units L=length P=pressure T=time Back to Calculations

                      A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                      g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                      hf = Major losses for entire pipe [L]

                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                      hm = Minor losses for entire pipe [L]

                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                      k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                      L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                      program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                      location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                      zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                      this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                      Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                      available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                      and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                      Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                      Material C Material C

                      Asbestos Cement 140 Copper 130-140

                      Brass 130-140 Galvanized iron 120

                      Brick sewer 100 Glass 140

                      Cast-Iron Lead 130-140

                      New unlined 130 Plastic 140-150

                      10 yr old 107-113 Steel

                      20 yr old 89-100 Coal-tar enamel lined 145-150

                      30 yr old 75-90 New unlined 140-150

                      40 yr old 64-83 Riveted 110

                      ConcreteConcrete-lined

                      Steel forms 140 Tin 130

                      Wooden forms 120 Vitrif clay (good condition) 110-140

                      Centrifugally spun 135 Wood stave (avg condition) 120

                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                      Fitting K Fitting K

                      Valves Elbows

                      Globe fully open 10 Regular 90deg flanged 03

                      Angle fully open 2 Regular 90deg threaded 15

                      Gate fully open 015 Long radius 90deg flanged 02

                      Gate 14 closed 026 Long radius 90deg threaded 07

                      Gate 12 closed 21 Long radius 45deg threaded 02

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      Gate 34 closed 17 Regular 45deg threaded 04

                      Swing check forward flow 2

                      Swing check backward flow infinity Tees

                      Line flow flanged 02

                      180deg return bends Line flow threaded 09

                      Flanged 02 Branch flow flanged 10

                      Threaded 15 Branch flow threaded 20

                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                      Square Connection 05 Square Connection 10

                      Rounded Connection 02 Rounded Connection 10

                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                      Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                      entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                      One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                      entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                      P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                      to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                      the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                      and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                      pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                      result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                      be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                      lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                      LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                      bull

                      Trapezoidal Open Channel Design Calculation

                      Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                      Froude number Manning coefficient channel slope

                      To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                      Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                      Register to enable Calculate button

                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                      Links on this page Introduction Variables Manning n coefficients Error Messages References

                      IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                      beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                      The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                      In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                      Variables [] indicates dimensions To calculation

                      A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                      divided by vertical distance

                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                      Oslash = Angle formed by S

                      Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                      Material Manning n Material Manning n

                      Natural Streams Excavated Earth Channels

                      Clean and Straight 0030 Clean 0022

                      Major Rivers 0035 Gravelly 0025

                      Sluggish with Deep Pools 0040 Weedy 0030

                      Stony Cobbles 0035

                      Metals Floodplains

                      Brass 0011 Pasture Farmland 0035

                      Cast Iron 0013 Light Brush 0050

                      Smooth Steel 0012 Heavy Brush 0075

                      Corrugated Metal 0022 Trees 015

                      Non-Metals

                      Glass 0010 Finished Concrete 0012

                      Clay Tile 0014 Unfinished Concrete 0014

                      Brickwork 0015 Gravel 0029

                      Asphalt 0016 Earth 0025

                      Masonry 0025 Planed Wood 0012

                      Unplaned Wood 0013

                      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                      Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                      The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                      cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                      simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                      The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                      References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                      a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                      Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                      French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                      Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                      7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                      Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                      Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                      View the version 40 New Features List

                      Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                      AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                      From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                      View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                      Learn More About AFT Impulse 40

                      Details Views Brochure Demo

                      copy 2001-2007 Applied Flow Technology All Rights Reserved

                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                        • Local Disk
                          • Circular Culvert Design Calculations Software Equations
                              • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                  • Culvert Design Inlet and Outlet Control
                                      • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                          • Design of Circular Water Pipes using Hazen Williams Equation
                                              • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                  • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                      • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                          • Gradually Varied Flow Calculation Backwater profile
                                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                  • Hydraulic Jump Calculation
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                                                                          • Manning Equation
                                                                              • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                  • Non-Circular Open Channel Geometry
                                                                                      • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                              • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                • Local Disk
                                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                      • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                              • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                        • Local Disk
                                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

                        Design of Circular Water Pipes using Hazen Williams Equation

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                        Design of Circular Pressurized Water Pipes

                        Calculation uses Hazen-Williams friction loss equation (commonly used by Civil Engineers) Valid for water at

                        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                        ToOther single pipe calculators Hazen-Williams with pump curve Darcy-Weisbach without pump curve

                        Darcy-Weisbach with pump curveMultiple pipes Bypass Loop Pipe Network

                        LMNO Engineering home page Unit Conversions Page Trouble printing

                        Register to enable Calculate button

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        Topics Scenarios Common Questions Equations H-W Coefficients Minor Loss Coefficients

                        Piping Scenarios

                        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (1 of 5)12112007 40419 PM

                        Design of Circular Water Pipes using Hazen Williams Equation

                        Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

                        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

                        Design of Circular Water Pipes using Hazen Williams Equation

                        Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

                        Steady State Energy Equation used for this page Back to CalculationsObtained from References

                        Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

                        k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

                        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

                        Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

                        Design of Circular Water Pipes using Hazen Williams Equation

                        Material C Material C

                        Asbestos Cement 140 Copper 130-140

                        Brass 130-140 Galvanized iron 120

                        Brick sewer 100 Glass 140

                        Cast-Iron Lead 130-140

                        New unlined 130 Plastic 140-150

                        10 yr old 107-113 Steel

                        20 yr old 89-100 Coal-tar enamel lined 145-150

                        30 yr old 75-90 New unlined 140-150

                        40 yr old 64-83 Riveted 110

                        ConcreteConcrete-lined

                        Steel forms 140 Tin 130

                        Wooden forms 120 Vitrif clay (good condition) 110-140

                        Centrifugally spun 135 Wood stave (avg condition) 120

                        Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                        Fitting Km Fitting Km

                        Valves Elbows

                        Globe fully open 10 Regular 90deg flanged 03

                        Angle fully open 2 Regular 90deg threaded 15

                        Gate fully open 015 Long radius 90deg flanged 02

                        Gate 14 closed 026 Long radius 90deg threaded 07

                        Gate 12 closed 21 Long radius 45deg threaded 02

                        Gate 34 closed 17 Regular 45deg threaded 04

                        Swing check forward flow 2

                        Swing check backward flow infinity Tees

                        Line flow flanged 02

                        180deg return bends Line flow threaded 09

                        Flanged 02 Branch flow flanged 10

                        Threaded 15 Branch flow threaded 20

                        fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                        Design of Circular Water Pipes using Hazen Williams Equation

                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                        Square Connection 05 Square Connection 10

                        Rounded Connection 02 Rounded Connection 10

                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                        copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                        LMNOLMNOengcom httpwwwlmnoengcom

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                        DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

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                        DPlot Graphing Software for Scientists and Engineers - Home Page

                        Current Version (9 December 2007)The latest release version of DPlot is 2149 Check the Revision History page for a list of recent changes Licensed users should sign up for the mailing list to receive instructions for downloading the free upgrade or select Check for Updates on the Help menu within DPlot

                        NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

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                        Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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                        DPlot Graphing Software for Scientists and Engineers - Home Page

                        or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

                        DPlot AccessoriesDo you need a new coffee cup mouse pad or golf shirt Of course you do Visit our online Accessories Store today

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                        Gradually Varied Flow Calculation Backwater profile

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                        Gradually Varied Flow in Trapezoidal Channel

                        Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                        Compute normal and critical depths

                        To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                        LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                        Cross-Section of Trapezoidal Channel

                        Gradually Varied Flow Profiles

                        CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                        middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                        Gradually Varied Flow Calculation Backwater profile

                        Links on this page Equations Variables Manning n coefficients Error messages References

                        Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                        equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                        calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                        The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                        Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                        using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                        References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                        empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                        Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                        Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                        1985) along with the fundamental equations above to solve for Yc

                        Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                        the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                        Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                        critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                        For mild slopes (YngtYc)

                        If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                        water depth gets closer to Yn as the calculation proceeds further and further upstream

                        If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                        Gradually Varied Flow Calculation Backwater profile

                        The water depth gets closer to Yn as the calculation proceeds further and further upstream

                        If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                        is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                        For steep slopes (YcgtYn)

                        If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                        is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                        If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                        water depth gets closer to Yn as the calculation proceeds further and further downstream

                        If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                        water depth gets closer to Yn as the calculation proceeds further and further downstream

                        For critical slopes (Yc=Yn)

                        If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                        water depth gets closer to Yn as the calculation proceeds further and further upstream

                        If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                        water depth gets closer to Yn as the calculation proceeds further and further downstream

                        There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                        Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                        At control section i=1 and Yi=Ys

                        Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                        Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                        Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                        P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                        differential depth increments (this is the basis of the Improved Euler method)

                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                        Gradually Varied Flow Calculation Backwater profile

                        Then repeat the loop by incrementing i

                        The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                        Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                        Ap=Area at Xp [m2]

                        A2=Area for intermediate computation in Improved Euler method [m2]

                        dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                        (dYdX)2=Second depth increment for Improved Euler method [m]

                        B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                        Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                        Epy=Elevation of water surface at Xp [m]

                        F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                        g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                        P2=Second wetted perimeter computed in Improved Euler method [m]

                        Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                        Sf1=First energy slope for Improved Euler method [dimensionless]

                        Sf2=Second energy slope for Improved Euler method [dimensionless]

                        T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                        T2=Second top width computed in Improved Euler method [m]

                        Tp=Top width at Xp [m]

                        V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                        X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                        is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                        Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                        automatically set Xp to Xmax

                        Y=Water depth [m]Yc=Critical depth [m]

                        Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                        Yn=Normal depth [m]

                        Yp=Depth at Xp [m]

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                        Gradually Varied Flow Calculation Backwater profile

                        Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                        Y2=Second depth computed in Improved Euler method [m]

                        Z1=One channel side slope (horizontal to vertical ratio) [mm]

                        Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                        Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                        Material Manning n Material Manning n

                        Natural Streams Excavated Earth Channels

                        Clean and Straight 0030 Clean 0022

                        Major Rivers 0035 Gravelly 0025

                        Sluggish with Deep Pools 0040 Weedy 0030

                        Stony Cobbles 0035

                        Metals Floodplains

                        Brass 0011 Pasture Farmland 0035

                        Cast Iron 0013 Light Brush 0050

                        Smooth Steel 0012 Heavy Brush 0075

                        Corrugated Metal 0022 Trees 015

                        Non-Metals

                        Glass 0010 Finished Concrete 0012

                        Clay Tile 0014 Unfinished Concrete 0014

                        Brickwork 0015 Gravel 0029

                        Asphalt 0016 Earth 0025

                        Masonry 0025 Planed Wood 0012

                        Unplaned Wood 0013

                        Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                        20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                        Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                        Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                        is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                        References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                        Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                        Gradually Varied Flow Calculation Backwater profile

                        Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                        French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                        Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                        Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                        Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                        Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                        copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                        LMNOLMNOengcom httpwwwlmnoengcom

                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                        Hydraulic Jump Calculation

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                        Hydraulic Jump in Horizontal Rectangular Channel

                        Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                        jump length and energy loss

                        To LMNO Engineering home page (all calculations) Related open channel calculations

                        Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                        Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                        Hydraulic Jump Calculation

                        Register to enable Calculate button

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        Equations

                        Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                        V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                        L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                        where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                        Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                        What is a Hydraulic Jump

                        A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                        According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                        oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                        occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                        Hydraulic Jump Calculation

                        MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                        Need F1 gt1 Upstream flow must be supercritical

                        ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                        copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                        LMNOLMNOengcom httpwwwlmnoengcom

                        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                        Manning Equation

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                        Mannings Equation Calculator Software The open channel flow software website

                        LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                        Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

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                        The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                        and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                        The product AP is also known as the hydraulic radius Rh

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                        Non-Circular Open Channel Geometry

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                        Geometric Calculations for Non-Circular Partially Filled Channels

                        The open channel flow calculations software website

                        Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                        Equations (note that R=AP)

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                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                        Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                        losses

                        Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                        pipe Dont have to use all the pipes or nodes

                        To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                        Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                        Register to fully enable Calculate button

                        Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                        IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                        Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                        The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                        Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                        Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                        1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                        Pipe flows are adjusted iteratively using the following equation

                        until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                        Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                        Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                        Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

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                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                        where log is base 10 logarithm and ln is natural logarithm Variable definitions

                        Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                        Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                        Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                        Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                        The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                        ApplicationsThe pipe network calculation has many applications Two examples will be provided

                        1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                        pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                        2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                        Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                        Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                        Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                        A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                        n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                        Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                        Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                        References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                        Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                        LMNOLMNOengcom httpwwwlmnoengcom

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                        Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                        Weisbach - Moody friction losses)

                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                        (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                        Parabolic shaped pump curve is formed from the two points

                        ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                        curve Hazen-Williams with pump curve

                        Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                        Register to enable Calculate button

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                        IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                        A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                        For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                        (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                        Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                        Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                        calculation will look like

                        The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                        Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                        Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                        is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                        defined for liquids

                        Variables Units F=force L=length P=pressure T=time Back to Calculations

                        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                        is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                        A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                        hf = Major losses for entire pipe [L] Also known as friction losses

                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                        hm = Minor losses for entire pipe [L]

                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                        K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                        for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                        P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                        location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                        zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                        V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                        this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                        v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                        Fitting K Fitting K

                        Valves Elbows

                        Globe fully open 10 Regular 90deg flanged 03

                        Angle fully open 2 Regular 90deg threaded 15

                        Gate fully open 015 Long radius 90deg flanged 02

                        Gate 14 closed 026 Long radius 90deg threaded 07

                        Gate 12 closed 21 Long radius 45deg threaded 02

                        Gate 34 closed 17 Regular 45deg threaded 04

                        Swing check forward flow 2

                        Swing check backward flow infinity Tees

                        Line flow flanged 02

                        180deg return bends Line flow threaded 09

                        Flanged 02 Branch flow flanged 10

                        Threaded 15 Branch flow threaded 20

                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                        Square Connection 05 Square Connection 10

                        Rounded Connection 02 Rounded Connection 10

                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                        Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                        The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                        Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                        the pipe or K for the suction pipe was entered as greater than K for the entire system

                        Other messagesK must be gt=1 If Q known Solve for D and V

                        3=0 then K must be gt 1 in order to solve

                        Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                        reservoirs are defined to be at zero pressure thus zero pressure difference

                        Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                        Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                        References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                        Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                        Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                        Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                        Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                        White F M 1979 Fluid Mechanics McGraw-Hill Inc

                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                        LMNOLMNOengcom httpwwwlmnoengcom

                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                        Circular Pressurized Water Pipes with Pump Curve

                        (Hazen Williams)

                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                        (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                        ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                        curve Darcy-Weisbach with pump curve

                        Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                        Register to enable Calculate button

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                        IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                        function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                        manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                        Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                        Equations and Methodology Back to Calculations

                        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                        The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                        calculation will look like

                        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                        Variables Units L=length P=pressure T=time Back to Calculations

                        A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                        g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                        hf = Major losses for entire pipe [L]

                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                        hm = Minor losses for entire pipe [L]

                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                        k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                        L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                        different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                        program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                        location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                        zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                        this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                        Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                        available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                        and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                        curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                        Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                        Material C Material C

                        Asbestos Cement 140 Copper 130-140

                        Brass 130-140 Galvanized iron 120

                        Brick sewer 100 Glass 140

                        Cast-Iron Lead 130-140

                        New unlined 130 Plastic 140-150

                        10 yr old 107-113 Steel

                        20 yr old 89-100 Coal-tar enamel lined 145-150

                        30 yr old 75-90 New unlined 140-150

                        40 yr old 64-83 Riveted 110

                        ConcreteConcrete-lined

                        Steel forms 140 Tin 130

                        Wooden forms 120 Vitrif clay (good condition) 110-140

                        Centrifugally spun 135 Wood stave (avg condition) 120

                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                        Fitting K Fitting K

                        Valves Elbows

                        Globe fully open 10 Regular 90deg flanged 03

                        Angle fully open 2 Regular 90deg threaded 15

                        Gate fully open 015 Long radius 90deg flanged 02

                        Gate 14 closed 026 Long radius 90deg threaded 07

                        Gate 12 closed 21 Long radius 45deg threaded 02

                        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                        Gate 34 closed 17 Regular 45deg threaded 04

                        Swing check forward flow 2

                        Swing check backward flow infinity Tees

                        Line flow flanged 02

                        180deg return bends Line flow threaded 09

                        Flanged 02 Branch flow flanged 10

                        Threaded 15 Branch flow threaded 20

                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                        Square Connection 05 Square Connection 10

                        Rounded Connection 02 Rounded Connection 10

                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                        Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                        entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                        One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                        entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                        P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                        to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                        the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                        and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                        pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                        result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                        be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                        lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                        LMNOLMNOengcom httpwwwlmnoengcom

                        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                        Trapezoidal Open Channel Design Calculation

                        Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                        Froude number Manning coefficient channel slope

                        To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                        Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                        Register to enable Calculate button

                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                        Links on this page Introduction Variables Manning n coefficients Error Messages References

                        IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                        beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                        The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                        In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                        Variables [] indicates dimensions To calculation

                        A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                        divided by vertical distance

                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                        Oslash = Angle formed by S

                        Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                        Material Manning n Material Manning n

                        Natural Streams Excavated Earth Channels

                        Clean and Straight 0030 Clean 0022

                        Major Rivers 0035 Gravelly 0025

                        Sluggish with Deep Pools 0040 Weedy 0030

                        Stony Cobbles 0035

                        Metals Floodplains

                        Brass 0011 Pasture Farmland 0035

                        Cast Iron 0013 Light Brush 0050

                        Smooth Steel 0012 Heavy Brush 0075

                        Corrugated Metal 0022 Trees 015

                        Non-Metals

                        Glass 0010 Finished Concrete 0012

                        Clay Tile 0014 Unfinished Concrete 0014

                        Brickwork 0015 Gravel 0029

                        Asphalt 0016 Earth 0025

                        Masonry 0025 Planed Wood 0012

                        Unplaned Wood 0013

                        Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                        Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                        Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                        Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                        The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                        cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                        simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                        The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                        References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                        a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                        Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                        French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                        Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                        7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                        Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                        Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                        View the version 40 New Features List

                        Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                        AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                        components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                        From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                        View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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                        copy 2001-2007 Applied Flow Technology All Rights Reserved

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                        • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                          • Local Disk
                            • Circular Culvert Design Calculations Software Equations
                                • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                  • Local Disk
                                    • Culvert Design Inlet and Outlet Control
                                        • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                          • Local Disk
                                            • Design of Circular Water Pipes using Hazen Williams Equation
                                                • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                  • Local Disk
                                                    • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                        • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                          • Local Disk
                                                            • Gradually Varied Flow Calculation Backwater profile
                                                                • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                  • Local Disk
                                                                    • Hydraulic Jump Calculation
                                                                        • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                          • Local Disk
                                                                            • Manning Equation
                                                                                • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                  • Local Disk
                                                                                    • Non-Circular Open Channel Geometry
                                                                                        • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                          • Local Disk
                                                                                            • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                  • Local Disk
                                                                                                    • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                        • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                          • Local Disk
                                                                                                            • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                  • Local Disk
                                                                                                                    • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                        • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                          • Local Disk
                                                                                                                            • Waterhammer surge analysis and transient analysis pipe flow modeling software

                          Design of Circular Water Pipes using Hazen Williams Equation

                          Common Questions Back to CalculationsI took fluid mechanics a long long time ago What is head Why does it have units of length Head is energy per unit weight of fluid (ie Force x LengthWeight = Length) The program on this page solves the energy equation (shown below) we call energy headWhy is Pressure=0 for a reservoir A reservoir is open to the atmosphere so its gage pressure is zeroWhy is Velocity=0 for a reservoir This is a common assumption in fluid mechanics and is based on the fact that a reservoir has a large surface area Therefore the water level drops very little even if a lot of water flows out of the reservoir A reservoir may physically be a lake or a large diameter tankWhat is a main and a lateral A main is a large diameter water supply pipe that has many smaller diameter laterals branching off of it to supply water to individual residences businesses or sub-divisions In fluid mechanics we set V=0 for the main since it has a large diameter (relative to the lateral) and thus a very small velocity To further justify the V=0 assumption the mains pressure is typically high so the velocity head in the main is negligible The main is drawn such that it is coming out of your computer monitor

                          fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (2 of 5)12112007 40419 PM

                          Design of Circular Water Pipes using Hazen Williams Equation

                          Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

                          Steady State Energy Equation used for this page Back to CalculationsObtained from References

                          Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

                          k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

                          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

                          Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                          fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

                          Design of Circular Water Pipes using Hazen Williams Equation

                          Material C Material C

                          Asbestos Cement 140 Copper 130-140

                          Brass 130-140 Galvanized iron 120

                          Brick sewer 100 Glass 140

                          Cast-Iron Lead 130-140

                          New unlined 130 Plastic 140-150

                          10 yr old 107-113 Steel

                          20 yr old 89-100 Coal-tar enamel lined 145-150

                          30 yr old 75-90 New unlined 140-150

                          40 yr old 64-83 Riveted 110

                          ConcreteConcrete-lined

                          Steel forms 140 Tin 130

                          Wooden forms 120 Vitrif clay (good condition) 110-140

                          Centrifugally spun 135 Wood stave (avg condition) 120

                          Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                          Fitting Km Fitting Km

                          Valves Elbows

                          Globe fully open 10 Regular 90deg flanged 03

                          Angle fully open 2 Regular 90deg threaded 15

                          Gate fully open 015 Long radius 90deg flanged 02

                          Gate 14 closed 026 Long radius 90deg threaded 07

                          Gate 12 closed 21 Long radius 45deg threaded 02

                          Gate 34 closed 17 Regular 45deg threaded 04

                          Swing check forward flow 2

                          Swing check backward flow infinity Tees

                          Line flow flanged 02

                          180deg return bends Line flow threaded 09

                          Flanged 02 Branch flow flanged 10

                          Threaded 15 Branch flow threaded 20

                          fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                          Design of Circular Water Pipes using Hazen Williams Equation

                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                          Square Connection 05 Square Connection 10

                          Rounded Connection 02 Rounded Connection 10

                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                          copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                          LMNOLMNOengcom httpwwwlmnoengcom

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                          DPlot Graphing Software for Scientists and Engineers - Home Page

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                          Gradually Varied Flow Calculation Backwater profile

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                          Gradually Varied Flow in Trapezoidal Channel

                          Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                          Compute normal and critical depths

                          To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                          LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                          Cross-Section of Trapezoidal Channel

                          Gradually Varied Flow Profiles

                          CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                          middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                          Gradually Varied Flow Calculation Backwater profile

                          Links on this page Equations Variables Manning n coefficients Error messages References

                          Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                          equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                          calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                          The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                          Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                          using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                          References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                          empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                          Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                          Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                          1985) along with the fundamental equations above to solve for Yc

                          Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                          the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                          Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                          critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                          For mild slopes (YngtYc)

                          If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                          water depth gets closer to Yn as the calculation proceeds further and further upstream

                          If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                          Gradually Varied Flow Calculation Backwater profile

                          The water depth gets closer to Yn as the calculation proceeds further and further upstream

                          If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                          is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                          For steep slopes (YcgtYn)

                          If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                          is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                          If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                          water depth gets closer to Yn as the calculation proceeds further and further downstream

                          If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                          water depth gets closer to Yn as the calculation proceeds further and further downstream

                          For critical slopes (Yc=Yn)

                          If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                          water depth gets closer to Yn as the calculation proceeds further and further upstream

                          If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                          water depth gets closer to Yn as the calculation proceeds further and further downstream

                          There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                          Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                          At control section i=1 and Yi=Ys

                          Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                          Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                          Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                          P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                          differential depth increments (this is the basis of the Improved Euler method)

                          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                          Gradually Varied Flow Calculation Backwater profile

                          Then repeat the loop by incrementing i

                          The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                          Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                          Ap=Area at Xp [m2]

                          A2=Area for intermediate computation in Improved Euler method [m2]

                          dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                          (dYdX)2=Second depth increment for Improved Euler method [m]

                          B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                          Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                          Epy=Elevation of water surface at Xp [m]

                          F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                          g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                          P2=Second wetted perimeter computed in Improved Euler method [m]

                          Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                          Sf1=First energy slope for Improved Euler method [dimensionless]

                          Sf2=Second energy slope for Improved Euler method [dimensionless]

                          T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                          T2=Second top width computed in Improved Euler method [m]

                          Tp=Top width at Xp [m]

                          V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                          X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                          is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                          Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                          automatically set Xp to Xmax

                          Y=Water depth [m]Yc=Critical depth [m]

                          Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                          Yn=Normal depth [m]

                          Yp=Depth at Xp [m]

                          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

                          Gradually Varied Flow Calculation Backwater profile

                          Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                          Y2=Second depth computed in Improved Euler method [m]

                          Z1=One channel side slope (horizontal to vertical ratio) [mm]

                          Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                          Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                          Material Manning n Material Manning n

                          Natural Streams Excavated Earth Channels

                          Clean and Straight 0030 Clean 0022

                          Major Rivers 0035 Gravelly 0025

                          Sluggish with Deep Pools 0040 Weedy 0030

                          Stony Cobbles 0035

                          Metals Floodplains

                          Brass 0011 Pasture Farmland 0035

                          Cast Iron 0013 Light Brush 0050

                          Smooth Steel 0012 Heavy Brush 0075

                          Corrugated Metal 0022 Trees 015

                          Non-Metals

                          Glass 0010 Finished Concrete 0012

                          Clay Tile 0014 Unfinished Concrete 0014

                          Brickwork 0015 Gravel 0029

                          Asphalt 0016 Earth 0025

                          Masonry 0025 Planed Wood 0012

                          Unplaned Wood 0013

                          Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                          20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                          Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                          Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                          is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                          References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                          Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                          Gradually Varied Flow Calculation Backwater profile

                          Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                          French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                          Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                          Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                          Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                          Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                          copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                          LMNOLMNOengcom httpwwwlmnoengcom

                          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                          Hydraulic Jump Calculation

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                          Hydraulic Jump in Horizontal Rectangular Channel

                          Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                          jump length and energy loss

                          To LMNO Engineering home page (all calculations) Related open channel calculations

                          Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                          Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                          fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                          Hydraulic Jump Calculation

                          Register to enable Calculate button

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          Equations

                          Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                          V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                          L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                          where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                          Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                          What is a Hydraulic Jump

                          A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                          According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                          oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                          occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                          fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                          Hydraulic Jump Calculation

                          MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                          Need F1 gt1 Upstream flow must be supercritical

                          ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                          copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                          LMNOLMNOengcom httpwwwlmnoengcom

                          fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                          Manning Equation

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                          Mannings Equation Calculator Software The open channel flow software website

                          LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                          Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                          and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                          The product AP is also known as the hydraulic radius Rh

                          fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                          Non-Circular Open Channel Geometry

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                          Geometric Calculations for Non-Circular Partially Filled Channels

                          The open channel flow calculations software website

                          Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                          Equations (note that R=AP)

                          fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                          bull

                          Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                          losses

                          Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                          pipe Dont have to use all the pipes or nodes

                          To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                          Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                          Register to fully enable Calculate button

                          Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                          IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                          Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                          The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                          Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                          Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                          1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                          Pipe flows are adjusted iteratively using the following equation

                          until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                          Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                          Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                          Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                          where log is base 10 logarithm and ln is natural logarithm Variable definitions

                          Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                          Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                          Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                          Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                          The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                          ApplicationsThe pipe network calculation has many applications Two examples will be provided

                          1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                          pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                          2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                          Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                          Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                          Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                          A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                          n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                          Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                          Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                          References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                          Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                          LMNOLMNOengcom httpwwwlmnoengcom

                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          bull

                          Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                          Weisbach - Moody friction losses)

                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                          (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                          Parabolic shaped pump curve is formed from the two points

                          ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                          curve Hazen-Williams with pump curve

                          Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                          Register to enable Calculate button

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                          IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                          A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                          For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                          (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                          Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                          calculation will look like

                          The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                          Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                          Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                          is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                          defined for liquids

                          Variables Units F=force L=length P=pressure T=time Back to Calculations

                          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                          A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                          hf = Major losses for entire pipe [L] Also known as friction losses

                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                          hm = Minor losses for entire pipe [L]

                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                          K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                          for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                          P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                          location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                          zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                          this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                          v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                          Fitting K Fitting K

                          Valves Elbows

                          Globe fully open 10 Regular 90deg flanged 03

                          Angle fully open 2 Regular 90deg threaded 15

                          Gate fully open 015 Long radius 90deg flanged 02

                          Gate 14 closed 026 Long radius 90deg threaded 07

                          Gate 12 closed 21 Long radius 45deg threaded 02

                          Gate 34 closed 17 Regular 45deg threaded 04

                          Swing check forward flow 2

                          Swing check backward flow infinity Tees

                          Line flow flanged 02

                          180deg return bends Line flow threaded 09

                          Flanged 02 Branch flow flanged 10

                          Threaded 15 Branch flow threaded 20

                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          Square Connection 05 Square Connection 10

                          Rounded Connection 02 Rounded Connection 10

                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                          Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                          The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                          Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                          the pipe or K for the suction pipe was entered as greater than K for the entire system

                          Other messagesK must be gt=1 If Q known Solve for D and V

                          3=0 then K must be gt 1 in order to solve

                          Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                          reservoirs are defined to be at zero pressure thus zero pressure difference

                          Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                          Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                          References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                          Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                          Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                          Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                          Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                          White F M 1979 Fluid Mechanics McGraw-Hill Inc

                          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                          LMNOLMNOengcom httpwwwlmnoengcom

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                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          bull

                          Circular Pressurized Water Pipes with Pump Curve

                          (Hazen Williams)

                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                          (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                          temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                          ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                          curve Darcy-Weisbach with pump curve

                          Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                          Register to enable Calculate button

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                          IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                          function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                          manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                          Equations and Methodology Back to Calculations

                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                          calculation will look like

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                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                          Variables Units L=length P=pressure T=time Back to Calculations

                          A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                          g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                          hf = Major losses for entire pipe [L]

                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                          hm = Minor losses for entire pipe [L]

                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                          k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                          L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                          program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                          location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                          zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                          this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                          Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                          available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                          and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                          Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                          Material C Material C

                          Asbestos Cement 140 Copper 130-140

                          Brass 130-140 Galvanized iron 120

                          Brick sewer 100 Glass 140

                          Cast-Iron Lead 130-140

                          New unlined 130 Plastic 140-150

                          10 yr old 107-113 Steel

                          20 yr old 89-100 Coal-tar enamel lined 145-150

                          30 yr old 75-90 New unlined 140-150

                          40 yr old 64-83 Riveted 110

                          ConcreteConcrete-lined

                          Steel forms 140 Tin 130

                          Wooden forms 120 Vitrif clay (good condition) 110-140

                          Centrifugally spun 135 Wood stave (avg condition) 120

                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                          Fitting K Fitting K

                          Valves Elbows

                          Globe fully open 10 Regular 90deg flanged 03

                          Angle fully open 2 Regular 90deg threaded 15

                          Gate fully open 015 Long radius 90deg flanged 02

                          Gate 14 closed 026 Long radius 90deg threaded 07

                          Gate 12 closed 21 Long radius 45deg threaded 02

                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          Gate 34 closed 17 Regular 45deg threaded 04

                          Swing check forward flow 2

                          Swing check backward flow infinity Tees

                          Line flow flanged 02

                          180deg return bends Line flow threaded 09

                          Flanged 02 Branch flow flanged 10

                          Threaded 15 Branch flow threaded 20

                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                          Square Connection 05 Square Connection 10

                          Rounded Connection 02 Rounded Connection 10

                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                          Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                          entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                          One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                          entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                          P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                          to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                          the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                          and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                          pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                          result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                          be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                          lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                          LMNOLMNOengcom httpwwwlmnoengcom

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                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                          bull

                          Trapezoidal Open Channel Design Calculation

                          Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                          Froude number Manning coefficient channel slope

                          To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                          Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                          Register to enable Calculate button

                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                          Links on this page Introduction Variables Manning n coefficients Error Messages References

                          IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                          beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                          The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                          In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                          Variables [] indicates dimensions To calculation

                          A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                          divided by vertical distance

                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                          Oslash = Angle formed by S

                          Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                          Material Manning n Material Manning n

                          Natural Streams Excavated Earth Channels

                          Clean and Straight 0030 Clean 0022

                          Major Rivers 0035 Gravelly 0025

                          Sluggish with Deep Pools 0040 Weedy 0030

                          Stony Cobbles 0035

                          Metals Floodplains

                          Brass 0011 Pasture Farmland 0035

                          Cast Iron 0013 Light Brush 0050

                          Smooth Steel 0012 Heavy Brush 0075

                          Corrugated Metal 0022 Trees 015

                          Non-Metals

                          Glass 0010 Finished Concrete 0012

                          Clay Tile 0014 Unfinished Concrete 0014

                          Brickwork 0015 Gravel 0029

                          Asphalt 0016 Earth 0025

                          Masonry 0025 Planed Wood 0012

                          Unplaned Wood 0013

                          Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                          Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                          Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                          Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                          The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                          cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                          simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                          The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                          References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                          a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                          c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                          e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                          Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                          French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                          d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                          Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                          b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                          7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                          Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                          Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                          View the version 40 New Features List

                          Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                          AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                          fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                          components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                          From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                          View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                          Learn More About AFT Impulse 40

                          Details Views Brochure Demo

                          copy 2001-2007 Applied Flow Technology All Rights Reserved

                          fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                          • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                            • Local Disk
                              • Circular Culvert Design Calculations Software Equations
                                  • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                    • Local Disk
                                      • Culvert Design Inlet and Outlet Control
                                          • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                            • Local Disk
                                              • Design of Circular Water Pipes using Hazen Williams Equation
                                                  • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                    • Local Disk
                                                      • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                          • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                            • Local Disk
                                                              • Gradually Varied Flow Calculation Backwater profile
                                                                  • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                    • Local Disk
                                                                      • Hydraulic Jump Calculation
                                                                          • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                            • Local Disk
                                                                              • Manning Equation
                                                                                  • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                    • Local Disk
                                                                                      • Non-Circular Open Channel Geometry
                                                                                          • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                            • Local Disk
                                                                                              • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                  • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                    • Local Disk
                                                                                                      • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                          • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                              • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                  • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                    • Local Disk
                                                                                                                      • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                          • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                            • Local Disk
                                                                                                                              • Waterhammer surge analysis and transient analysis pipe flow modeling software

                            Design of Circular Water Pipes using Hazen Williams Equation

                            Can I model flow between two reservoirs using either Scenario B or E Yes you can If using Scenario E just set P1-P2=0 Scenario B automatically sets P1-P2=0Can I model flow between two mains using either Scenario B or E Only if the pressure is the same in both mainsHow do I model a pipe discharging freely to the atmosphere Use Scenario A C or F Since P2=0 (relative to atmospheric pressure) P1-P2 that is input or output will be P1What are minor losses Minor losses are head (energy) losses due to valves pipe bends pipe entrances (for water flowing from a tank to a pipe) and pipe exits (water flowing from a pipe to a tank) as opposed to a major loss which is due to the friction of water flowing through a length of pipe Minor loss coefficients (Km) are tabulated below For our program all of the pipes have the same diameter so you can add up all your minor loss coefficients and enter the sum in the Minor Loss Coefficient input boxIm confused about pumps Only input Pump Head if the pump is between points 1 and 2 Otherwise enter 0 for Pump HeadYour program is great What are its limitations Pipes must all have the same diameter Pump curves cannot be implemented The fluid must be waterWhere can I find additional information ReferencesWhat is Driving Head See below

                            Steady State Energy Equation used for this page Back to CalculationsObtained from References

                            Driving Head (DH) = left side of the first equationg = acceleration due to gravity = 32174 fts2 = 98066 ms2

                            k = unit conversion factor = 1318 for English units = 085 for Metric unitsS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsPump Power = SQHp Note that 1 horsepower = 550 ft-lbs

                            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q and Q known Solve for Pipe Diameter These two calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision

                            Table of Hazen-Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                            fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (3 of 5)12112007 40419 PM

                            Design of Circular Water Pipes using Hazen Williams Equation

                            Material C Material C

                            Asbestos Cement 140 Copper 130-140

                            Brass 130-140 Galvanized iron 120

                            Brick sewer 100 Glass 140

                            Cast-Iron Lead 130-140

                            New unlined 130 Plastic 140-150

                            10 yr old 107-113 Steel

                            20 yr old 89-100 Coal-tar enamel lined 145-150

                            30 yr old 75-90 New unlined 140-150

                            40 yr old 64-83 Riveted 110

                            ConcreteConcrete-lined

                            Steel forms 140 Tin 130

                            Wooden forms 120 Vitrif clay (good condition) 110-140

                            Centrifugally spun 135 Wood stave (avg condition) 120

                            Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                            Fitting Km Fitting Km

                            Valves Elbows

                            Globe fully open 10 Regular 90deg flanged 03

                            Angle fully open 2 Regular 90deg threaded 15

                            Gate fully open 015 Long radius 90deg flanged 02

                            Gate 14 closed 026 Long radius 90deg threaded 07

                            Gate 12 closed 21 Long radius 45deg threaded 02

                            Gate 34 closed 17 Regular 45deg threaded 04

                            Swing check forward flow 2

                            Swing check backward flow infinity Tees

                            Line flow flanged 02

                            180deg return bends Line flow threaded 09

                            Flanged 02 Branch flow flanged 10

                            Threaded 15 Branch flow threaded 20

                            fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                            Design of Circular Water Pipes using Hazen Williams Equation

                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                            Square Connection 05 Square Connection 10

                            Rounded Connection 02 Rounded Connection 10

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                            copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

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                            Gradually Varied Flow Calculation Backwater profile

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                            Gradually Varied Flow in Trapezoidal Channel

                            Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                            Compute normal and critical depths

                            To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                            LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                            Cross-Section of Trapezoidal Channel

                            Gradually Varied Flow Profiles

                            CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                            middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                            Gradually Varied Flow Calculation Backwater profile

                            Links on this page Equations Variables Manning n coefficients Error messages References

                            Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                            equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                            calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                            The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                            Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                            using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                            References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                            empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                            Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                            Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                            1985) along with the fundamental equations above to solve for Yc

                            Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                            the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                            Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                            critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                            For mild slopes (YngtYc)

                            If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                            water depth gets closer to Yn as the calculation proceeds further and further upstream

                            If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

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                            Gradually Varied Flow Calculation Backwater profile

                            The water depth gets closer to Yn as the calculation proceeds further and further upstream

                            If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                            is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                            For steep slopes (YcgtYn)

                            If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                            is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                            If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                            water depth gets closer to Yn as the calculation proceeds further and further downstream

                            If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                            water depth gets closer to Yn as the calculation proceeds further and further downstream

                            For critical slopes (Yc=Yn)

                            If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                            water depth gets closer to Yn as the calculation proceeds further and further upstream

                            If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                            water depth gets closer to Yn as the calculation proceeds further and further downstream

                            There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                            Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                            At control section i=1 and Yi=Ys

                            Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                            Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                            Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                            P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                            differential depth increments (this is the basis of the Improved Euler method)

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                            Gradually Varied Flow Calculation Backwater profile

                            Then repeat the loop by incrementing i

                            The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                            Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                            Ap=Area at Xp [m2]

                            A2=Area for intermediate computation in Improved Euler method [m2]

                            dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                            (dYdX)2=Second depth increment for Improved Euler method [m]

                            B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                            Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                            Epy=Elevation of water surface at Xp [m]

                            F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                            g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                            P2=Second wetted perimeter computed in Improved Euler method [m]

                            Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                            Sf1=First energy slope for Improved Euler method [dimensionless]

                            Sf2=Second energy slope for Improved Euler method [dimensionless]

                            T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                            T2=Second top width computed in Improved Euler method [m]

                            Tp=Top width at Xp [m]

                            V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                            X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                            is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                            Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                            automatically set Xp to Xmax

                            Y=Water depth [m]Yc=Critical depth [m]

                            Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                            Yn=Normal depth [m]

                            Yp=Depth at Xp [m]

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                            Gradually Varied Flow Calculation Backwater profile

                            Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                            Y2=Second depth computed in Improved Euler method [m]

                            Z1=One channel side slope (horizontal to vertical ratio) [mm]

                            Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                            Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                            Material Manning n Material Manning n

                            Natural Streams Excavated Earth Channels

                            Clean and Straight 0030 Clean 0022

                            Major Rivers 0035 Gravelly 0025

                            Sluggish with Deep Pools 0040 Weedy 0030

                            Stony Cobbles 0035

                            Metals Floodplains

                            Brass 0011 Pasture Farmland 0035

                            Cast Iron 0013 Light Brush 0050

                            Smooth Steel 0012 Heavy Brush 0075

                            Corrugated Metal 0022 Trees 015

                            Non-Metals

                            Glass 0010 Finished Concrete 0012

                            Clay Tile 0014 Unfinished Concrete 0014

                            Brickwork 0015 Gravel 0029

                            Asphalt 0016 Earth 0025

                            Masonry 0025 Planed Wood 0012

                            Unplaned Wood 0013

                            Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                            20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                            Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                            Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                            is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                            References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                            Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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                            Gradually Varied Flow Calculation Backwater profile

                            Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                            French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                            Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                            Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                            Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                            Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                            copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                            LMNOLMNOengcom httpwwwlmnoengcom

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                            Hydraulic Jump Calculation

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                            Hydraulic Jump in Horizontal Rectangular Channel

                            Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                            jump length and energy loss

                            To LMNO Engineering home page (all calculations) Related open channel calculations

                            Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                            Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                            Hydraulic Jump Calculation

                            Register to enable Calculate button

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            Equations

                            Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                            V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                            L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                            where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                            Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                            What is a Hydraulic Jump

                            A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                            According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                            oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                            occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                            Hydraulic Jump Calculation

                            MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                            Need F1 gt1 Upstream flow must be supercritical

                            ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                            copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                            LMNOLMNOengcom httpwwwlmnoengcom

                            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                            Manning Equation

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                            Mannings Equation Calculator Software The open channel flow software website

                            LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                            Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                            and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                            The product AP is also known as the hydraulic radius Rh

                            fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                            Non-Circular Open Channel Geometry

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                            Geometric Calculations for Non-Circular Partially Filled Channels

                            The open channel flow calculations software website

                            Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                            Equations (note that R=AP)

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                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                            Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                            losses

                            Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                            pipe Dont have to use all the pipes or nodes

                            To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                            Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                            Register to fully enable Calculate button

                            Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                            IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                            Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                            The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                            Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                            Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                            1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                            Pipe flows are adjusted iteratively using the following equation

                            until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                            Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                            Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                            Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                            where log is base 10 logarithm and ln is natural logarithm Variable definitions

                            Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                            Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                            Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                            Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                            The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                            ApplicationsThe pipe network calculation has many applications Two examples will be provided

                            1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                            pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                            2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                            Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                            Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                            Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                            A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                            n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                            Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                            Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                            References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                            Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                            LMNOLMNOengcom httpwwwlmnoengcom

                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            bull

                            Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                            Weisbach - Moody friction losses)

                            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                            (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                            Parabolic shaped pump curve is formed from the two points

                            ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                            curve Hazen-Williams with pump curve

                            Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                            Register to enable Calculate button

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                            IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                            A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                            For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                            (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                            Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                            calculation will look like

                            The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                            Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                            Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                            is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                            defined for liquids

                            Variables Units F=force L=length P=pressure T=time Back to Calculations

                            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                            A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                            hf = Major losses for entire pipe [L] Also known as friction losses

                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                            hm = Minor losses for entire pipe [L]

                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                            K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                            for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                            P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                            location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                            zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                            this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                            v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                            Fitting K Fitting K

                            Valves Elbows

                            Globe fully open 10 Regular 90deg flanged 03

                            Angle fully open 2 Regular 90deg threaded 15

                            Gate fully open 015 Long radius 90deg flanged 02

                            Gate 14 closed 026 Long radius 90deg threaded 07

                            Gate 12 closed 21 Long radius 45deg threaded 02

                            Gate 34 closed 17 Regular 45deg threaded 04

                            Swing check forward flow 2

                            Swing check backward flow infinity Tees

                            Line flow flanged 02

                            180deg return bends Line flow threaded 09

                            Flanged 02 Branch flow flanged 10

                            Threaded 15 Branch flow threaded 20

                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            Square Connection 05 Square Connection 10

                            Rounded Connection 02 Rounded Connection 10

                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                            Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                            The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                            Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                            the pipe or K for the suction pipe was entered as greater than K for the entire system

                            Other messagesK must be gt=1 If Q known Solve for D and V

                            3=0 then K must be gt 1 in order to solve

                            Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                            reservoirs are defined to be at zero pressure thus zero pressure difference

                            Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                            Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                            References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                            Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                            Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                            Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                            Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                            White F M 1979 Fluid Mechanics McGraw-Hill Inc

                            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                            LMNOLMNOengcom httpwwwlmnoengcom

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                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            bull

                            Circular Pressurized Water Pipes with Pump Curve

                            (Hazen Williams)

                            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                            (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                            temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                            ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                            curve Darcy-Weisbach with pump curve

                            Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                            Register to enable Calculate button

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                            IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                            function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                            manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                            Equations and Methodology Back to Calculations

                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                            calculation will look like

                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                            Variables Units L=length P=pressure T=time Back to Calculations

                            A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                            g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                            hf = Major losses for entire pipe [L]

                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                            hm = Minor losses for entire pipe [L]

                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                            k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                            L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                            program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                            location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                            zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                            this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                            Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                            available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                            and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                            Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                            Material C Material C

                            Asbestos Cement 140 Copper 130-140

                            Brass 130-140 Galvanized iron 120

                            Brick sewer 100 Glass 140

                            Cast-Iron Lead 130-140

                            New unlined 130 Plastic 140-150

                            10 yr old 107-113 Steel

                            20 yr old 89-100 Coal-tar enamel lined 145-150

                            30 yr old 75-90 New unlined 140-150

                            40 yr old 64-83 Riveted 110

                            ConcreteConcrete-lined

                            Steel forms 140 Tin 130

                            Wooden forms 120 Vitrif clay (good condition) 110-140

                            Centrifugally spun 135 Wood stave (avg condition) 120

                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                            Fitting K Fitting K

                            Valves Elbows

                            Globe fully open 10 Regular 90deg flanged 03

                            Angle fully open 2 Regular 90deg threaded 15

                            Gate fully open 015 Long radius 90deg flanged 02

                            Gate 14 closed 026 Long radius 90deg threaded 07

                            Gate 12 closed 21 Long radius 45deg threaded 02

                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            Gate 34 closed 17 Regular 45deg threaded 04

                            Swing check forward flow 2

                            Swing check backward flow infinity Tees

                            Line flow flanged 02

                            180deg return bends Line flow threaded 09

                            Flanged 02 Branch flow flanged 10

                            Threaded 15 Branch flow threaded 20

                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                            Square Connection 05 Square Connection 10

                            Rounded Connection 02 Rounded Connection 10

                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                            Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                            entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                            One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                            entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                            P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                            to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                            the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                            and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                            pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                            result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                            be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                            lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                            LMNOLMNOengcom httpwwwlmnoengcom

                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                            bull

                            Trapezoidal Open Channel Design Calculation

                            Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                            Froude number Manning coefficient channel slope

                            To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                            Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                            Register to enable Calculate button

                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                            Links on this page Introduction Variables Manning n coefficients Error Messages References

                            IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                            beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                            The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                            In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                            Variables [] indicates dimensions To calculation

                            A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                            divided by vertical distance

                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                            Oslash = Angle formed by S

                            Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                            Material Manning n Material Manning n

                            Natural Streams Excavated Earth Channels

                            Clean and Straight 0030 Clean 0022

                            Major Rivers 0035 Gravelly 0025

                            Sluggish with Deep Pools 0040 Weedy 0030

                            Stony Cobbles 0035

                            Metals Floodplains

                            Brass 0011 Pasture Farmland 0035

                            Cast Iron 0013 Light Brush 0050

                            Smooth Steel 0012 Heavy Brush 0075

                            Corrugated Metal 0022 Trees 015

                            Non-Metals

                            Glass 0010 Finished Concrete 0012

                            Clay Tile 0014 Unfinished Concrete 0014

                            Brickwork 0015 Gravel 0029

                            Asphalt 0016 Earth 0025

                            Masonry 0025 Planed Wood 0012

                            Unplaned Wood 0013

                            Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                            Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                            Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                            Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                            The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                            cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                            simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                            The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                            References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                            a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                            c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                            e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                            Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                            French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                            d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                            Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                            b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                            7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                            Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                            Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                            View the version 40 New Features List

                            Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                            AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                            components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                            From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                            View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                            Learn More About AFT Impulse 40

                            Details Views Brochure Demo

                            copy 2001-2007 Applied Flow Technology All Rights Reserved

                            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                            • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                              • Local Disk
                                • Circular Culvert Design Calculations Software Equations
                                    • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                      • Local Disk
                                        • Culvert Design Inlet and Outlet Control
                                            • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                              • Local Disk
                                                • Design of Circular Water Pipes using Hazen Williams Equation
                                                    • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                      • Local Disk
                                                        • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                            • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                              • Local Disk
                                                                • Gradually Varied Flow Calculation Backwater profile
                                                                    • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                      • Local Disk
                                                                        • Hydraulic Jump Calculation
                                                                            • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                              • Local Disk
                                                                                • Manning Equation
                                                                                    • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                      • Local Disk
                                                                                        • Non-Circular Open Channel Geometry
                                                                                            • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                              • Local Disk
                                                                                                • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                    • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                      • Local Disk
                                                                                                        • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                            • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                              • Local Disk
                                                                                                                • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                    • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                      • Local Disk
                                                                                                                        • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                            • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                              • Local Disk
                                                                                                                                • Waterhammer surge analysis and transient analysis pipe flow modeling software

                              Design of Circular Water Pipes using Hazen Williams Equation

                              Material C Material C

                              Asbestos Cement 140 Copper 130-140

                              Brass 130-140 Galvanized iron 120

                              Brick sewer 100 Glass 140

                              Cast-Iron Lead 130-140

                              New unlined 130 Plastic 140-150

                              10 yr old 107-113 Steel

                              20 yr old 89-100 Coal-tar enamel lined 145-150

                              30 yr old 75-90 New unlined 140-150

                              40 yr old 64-83 Riveted 110

                              ConcreteConcrete-lined

                              Steel forms 140 Tin 130

                              Wooden forms 120 Vitrif clay (good condition) 110-140

                              Centrifugally spun 135 Wood stave (avg condition) 120

                              Table of Minor Loss Coefficients (Km is unit-less) Back to CalculationsCompiled from References

                              Fitting Km Fitting Km

                              Valves Elbows

                              Globe fully open 10 Regular 90deg flanged 03

                              Angle fully open 2 Regular 90deg threaded 15

                              Gate fully open 015 Long radius 90deg flanged 02

                              Gate 14 closed 026 Long radius 90deg threaded 07

                              Gate 12 closed 21 Long radius 45deg threaded 02

                              Gate 34 closed 17 Regular 45deg threaded 04

                              Swing check forward flow 2

                              Swing check backward flow infinity Tees

                              Line flow flanged 02

                              180deg return bends Line flow threaded 09

                              Flanged 02 Branch flow flanged 10

                              Threaded 15 Branch flow threaded 20

                              fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (4 of 5)12112007 40419 PM

                              Design of Circular Water Pipes using Hazen Williams Equation

                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                              Square Connection 05 Square Connection 10

                              Rounded Connection 02 Rounded Connection 10

                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                              copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                              LMNOLMNOengcom httpwwwlmnoengcom

                              fileE|engineeringhydraulicsDesign20of20Circuter20Pipes20using20Hazen20Williams20Equationhtm (5 of 5)12112007 40419 PM

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                              Compatible with Windowsreg 95 98 2000 ME NT 2003 XP and Vista

                              DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

                              You can buy a single-user DPlot license for $45(US) or $55 for a CD sent by mail If you buy DPlot for your department we offer multi-user discounts Click the button below to purchase DPlot by credit card now or check the Buy Now page for more information on pricing and payment options

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                              DPlot Graphing Software for Scientists and Engineers - Home Page

                              Current Version (9 December 2007)The latest release version of DPlot is 2149 Check the Revision History page for a list of recent changes Licensed users should sign up for the mailing list to receive instructions for downloading the free upgrade or select Check for Updates on the Help menu within DPlot

                              NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

                              The most recent update includes 2D vector plots and the ability to draw antialiased curves and other graphic objects for more attractive graphs

                              Other ProductsIf you produce graphs with DPlot and would like to distribute them to others youll want to take a look at DPlot Viewer This is a free application that may be distributed to others without charge DPlot Viewer will display andor print any graph produced by DPlot

                              Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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                              DPlot Graphing Software for Scientists and Engineers - Home Page

                              or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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                              Gradually Varied Flow Calculation Backwater profile

                              bull

                              Gradually Varied Flow in Trapezoidal Channel

                              Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                              Compute normal and critical depths

                              To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                              LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                              Cross-Section of Trapezoidal Channel

                              Gradually Varied Flow Profiles

                              CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                              middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                              Gradually Varied Flow Calculation Backwater profile

                              Links on this page Equations Variables Manning n coefficients Error messages References

                              Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                              equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                              calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                              The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                              Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                              using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                              References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                              empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                              Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                              Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                              1985) along with the fundamental equations above to solve for Yc

                              Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                              the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                              Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                              critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                              For mild slopes (YngtYc)

                              If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                              water depth gets closer to Yn as the calculation proceeds further and further upstream

                              If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

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                              Gradually Varied Flow Calculation Backwater profile

                              The water depth gets closer to Yn as the calculation proceeds further and further upstream

                              If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                              is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                              For steep slopes (YcgtYn)

                              If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                              is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                              If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                              water depth gets closer to Yn as the calculation proceeds further and further downstream

                              If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                              water depth gets closer to Yn as the calculation proceeds further and further downstream

                              For critical slopes (Yc=Yn)

                              If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                              water depth gets closer to Yn as the calculation proceeds further and further upstream

                              If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                              water depth gets closer to Yn as the calculation proceeds further and further downstream

                              There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                              Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                              At control section i=1 and Yi=Ys

                              Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                              Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                              Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                              P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                              differential depth increments (this is the basis of the Improved Euler method)

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                              Gradually Varied Flow Calculation Backwater profile

                              Then repeat the loop by incrementing i

                              The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                              Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                              Ap=Area at Xp [m2]

                              A2=Area for intermediate computation in Improved Euler method [m2]

                              dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                              (dYdX)2=Second depth increment for Improved Euler method [m]

                              B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                              Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                              Epy=Elevation of water surface at Xp [m]

                              F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                              g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                              P2=Second wetted perimeter computed in Improved Euler method [m]

                              Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                              Sf1=First energy slope for Improved Euler method [dimensionless]

                              Sf2=Second energy slope for Improved Euler method [dimensionless]

                              T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                              T2=Second top width computed in Improved Euler method [m]

                              Tp=Top width at Xp [m]

                              V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                              X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                              is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                              Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                              automatically set Xp to Xmax

                              Y=Water depth [m]Yc=Critical depth [m]

                              Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                              Yn=Normal depth [m]

                              Yp=Depth at Xp [m]

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                              Gradually Varied Flow Calculation Backwater profile

                              Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                              Y2=Second depth computed in Improved Euler method [m]

                              Z1=One channel side slope (horizontal to vertical ratio) [mm]

                              Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                              Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                              Material Manning n Material Manning n

                              Natural Streams Excavated Earth Channels

                              Clean and Straight 0030 Clean 0022

                              Major Rivers 0035 Gravelly 0025

                              Sluggish with Deep Pools 0040 Weedy 0030

                              Stony Cobbles 0035

                              Metals Floodplains

                              Brass 0011 Pasture Farmland 0035

                              Cast Iron 0013 Light Brush 0050

                              Smooth Steel 0012 Heavy Brush 0075

                              Corrugated Metal 0022 Trees 015

                              Non-Metals

                              Glass 0010 Finished Concrete 0012

                              Clay Tile 0014 Unfinished Concrete 0014

                              Brickwork 0015 Gravel 0029

                              Asphalt 0016 Earth 0025

                              Masonry 0025 Planed Wood 0012

                              Unplaned Wood 0013

                              Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                              20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                              Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                              Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                              is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                              References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                              Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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                              Gradually Varied Flow Calculation Backwater profile

                              Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                              French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                              Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                              Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                              Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                              Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                              copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                              LMNOLMNOengcom httpwwwlmnoengcom

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                              Hydraulic Jump Calculation

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                              Hydraulic Jump in Horizontal Rectangular Channel

                              Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                              jump length and energy loss

                              To LMNO Engineering home page (all calculations) Related open channel calculations

                              Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                              Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                              fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                              Hydraulic Jump Calculation

                              Register to enable Calculate button

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              Equations

                              Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                              V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                              L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                              where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                              Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                              What is a Hydraulic Jump

                              A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                              According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                              oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                              occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                              Hydraulic Jump Calculation

                              MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                              Need F1 gt1 Upstream flow must be supercritical

                              ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                              copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                              LMNOLMNOengcom httpwwwlmnoengcom

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                              Manning Equation

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                              Mannings Equation Calculator Software The open channel flow software website

                              LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                              Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                              and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                              The product AP is also known as the hydraulic radius Rh

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                              Non-Circular Open Channel Geometry

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                              Geometric Calculations for Non-Circular Partially Filled Channels

                              The open channel flow calculations software website

                              Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                              Equations (note that R=AP)

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                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                              Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                              losses

                              Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                              pipe Dont have to use all the pipes or nodes

                              To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                              Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                              Register to fully enable Calculate button

                              Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                              IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                              Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                              The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                              Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                              Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                              1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                              Pipe flows are adjusted iteratively using the following equation

                              until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                              Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                              Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                              Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

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                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                              where log is base 10 logarithm and ln is natural logarithm Variable definitions

                              Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                              Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                              Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                              Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                              The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                              ApplicationsThe pipe network calculation has many applications Two examples will be provided

                              1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                              pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                              2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                              Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                              Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                              Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                              A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                              n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                              Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                              Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                              References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                              Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                              LMNOLMNOengcom httpwwwlmnoengcom

                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              bull

                              Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                              Weisbach - Moody friction losses)

                              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                              (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                              Parabolic shaped pump curve is formed from the two points

                              ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                              curve Hazen-Williams with pump curve

                              Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                              Register to enable Calculate button

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                              IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                              A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                              For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                              (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                              Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                              calculation will look like

                              The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                              Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                              Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                              is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                              defined for liquids

                              Variables Units F=force L=length P=pressure T=time Back to Calculations

                              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                              A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                              hf = Major losses for entire pipe [L] Also known as friction losses

                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                              hm = Minor losses for entire pipe [L]

                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                              K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                              for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                              P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                              location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                              zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                              this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                              v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                              Fitting K Fitting K

                              Valves Elbows

                              Globe fully open 10 Regular 90deg flanged 03

                              Angle fully open 2 Regular 90deg threaded 15

                              Gate fully open 015 Long radius 90deg flanged 02

                              Gate 14 closed 026 Long radius 90deg threaded 07

                              Gate 12 closed 21 Long radius 45deg threaded 02

                              Gate 34 closed 17 Regular 45deg threaded 04

                              Swing check forward flow 2

                              Swing check backward flow infinity Tees

                              Line flow flanged 02

                              180deg return bends Line flow threaded 09

                              Flanged 02 Branch flow flanged 10

                              Threaded 15 Branch flow threaded 20

                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              Square Connection 05 Square Connection 10

                              Rounded Connection 02 Rounded Connection 10

                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                              Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                              The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                              Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                              the pipe or K for the suction pipe was entered as greater than K for the entire system

                              Other messagesK must be gt=1 If Q known Solve for D and V

                              3=0 then K must be gt 1 in order to solve

                              Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                              reservoirs are defined to be at zero pressure thus zero pressure difference

                              Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                              Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                              References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                              Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                              Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                              Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                              Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                              White F M 1979 Fluid Mechanics McGraw-Hill Inc

                              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                              LMNOLMNOengcom httpwwwlmnoengcom

                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              bull

                              Circular Pressurized Water Pipes with Pump Curve

                              (Hazen Williams)

                              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                              (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                              temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                              ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                              curve Darcy-Weisbach with pump curve

                              Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                              Register to enable Calculate button

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                              IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                              function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                              manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                              Equations and Methodology Back to Calculations

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                              calculation will look like

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                              Variables Units L=length P=pressure T=time Back to Calculations

                              A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                              g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                              hf = Major losses for entire pipe [L]

                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                              hm = Minor losses for entire pipe [L]

                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                              k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                              L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                              program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                              location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                              zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                              this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                              Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                              available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                              and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                              Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                              Material C Material C

                              Asbestos Cement 140 Copper 130-140

                              Brass 130-140 Galvanized iron 120

                              Brick sewer 100 Glass 140

                              Cast-Iron Lead 130-140

                              New unlined 130 Plastic 140-150

                              10 yr old 107-113 Steel

                              20 yr old 89-100 Coal-tar enamel lined 145-150

                              30 yr old 75-90 New unlined 140-150

                              40 yr old 64-83 Riveted 110

                              ConcreteConcrete-lined

                              Steel forms 140 Tin 130

                              Wooden forms 120 Vitrif clay (good condition) 110-140

                              Centrifugally spun 135 Wood stave (avg condition) 120

                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                              Fitting K Fitting K

                              Valves Elbows

                              Globe fully open 10 Regular 90deg flanged 03

                              Angle fully open 2 Regular 90deg threaded 15

                              Gate fully open 015 Long radius 90deg flanged 02

                              Gate 14 closed 026 Long radius 90deg threaded 07

                              Gate 12 closed 21 Long radius 45deg threaded 02

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              Gate 34 closed 17 Regular 45deg threaded 04

                              Swing check forward flow 2

                              Swing check backward flow infinity Tees

                              Line flow flanged 02

                              180deg return bends Line flow threaded 09

                              Flanged 02 Branch flow flanged 10

                              Threaded 15 Branch flow threaded 20

                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                              Square Connection 05 Square Connection 10

                              Rounded Connection 02 Rounded Connection 10

                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                              Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                              entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                              One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                              entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                              P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                              to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                              the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                              and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                              pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                              result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                              be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                              lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                              LMNOLMNOengcom httpwwwlmnoengcom

                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                              bull

                              Trapezoidal Open Channel Design Calculation

                              Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                              Froude number Manning coefficient channel slope

                              To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                              Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                              Register to enable Calculate button

                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                              Links on this page Introduction Variables Manning n coefficients Error Messages References

                              IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                              beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                              The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                              In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                              Variables [] indicates dimensions To calculation

                              A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                              divided by vertical distance

                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                              Oslash = Angle formed by S

                              Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                              Material Manning n Material Manning n

                              Natural Streams Excavated Earth Channels

                              Clean and Straight 0030 Clean 0022

                              Major Rivers 0035 Gravelly 0025

                              Sluggish with Deep Pools 0040 Weedy 0030

                              Stony Cobbles 0035

                              Metals Floodplains

                              Brass 0011 Pasture Farmland 0035

                              Cast Iron 0013 Light Brush 0050

                              Smooth Steel 0012 Heavy Brush 0075

                              Corrugated Metal 0022 Trees 015

                              Non-Metals

                              Glass 0010 Finished Concrete 0012

                              Clay Tile 0014 Unfinished Concrete 0014

                              Brickwork 0015 Gravel 0029

                              Asphalt 0016 Earth 0025

                              Masonry 0025 Planed Wood 0012

                              Unplaned Wood 0013

                              Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                              Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                              Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                              Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                              The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                              cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                              simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                              The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                              References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                              a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                              c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                              e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                              Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                              French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                              d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                              Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                              b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                              7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                              Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                              Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                              View the version 40 New Features List

                              Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                              AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                              components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                              From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                              View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                              Learn More About AFT Impulse 40

                              Details Views Brochure Demo

                              copy 2001-2007 Applied Flow Technology All Rights Reserved

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                              • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                • Local Disk
                                  • Circular Culvert Design Calculations Software Equations
                                      • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                        • Local Disk
                                          • Culvert Design Inlet and Outlet Control
                                              • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                • Local Disk
                                                  • Design of Circular Water Pipes using Hazen Williams Equation
                                                      • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                        • Local Disk
                                                          • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                              • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                • Local Disk
                                                                  • Gradually Varied Flow Calculation Backwater profile
                                                                      • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                        • Local Disk
                                                                          • Hydraulic Jump Calculation
                                                                              • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                • Local Disk
                                                                                  • Manning Equation
                                                                                      • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                        • Local Disk
                                                                                          • Non-Circular Open Channel Geometry
                                                                                              • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                • Local Disk
                                                                                                  • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                      • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                        • Local Disk
                                                                                                          • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                              • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                • Local Disk
                                                                                                                  • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                      • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                        • Local Disk
                                                                                                                          • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                              • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                • Local Disk
                                                                                                                                  • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                Design of Circular Water Pipes using Hazen Williams Equation

                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                Square Connection 05 Square Connection 10

                                Rounded Connection 02 Rounded Connection 10

                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                copy 1998-2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                LMNOLMNOengcom httpwwwlmnoengcom

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                                Compatible with Windowsreg 95 98 2000 ME NT 2003 XP and Vista

                                DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

                                You can buy a single-user DPlot license for $45(US) or $55 for a CD sent by mail If you buy DPlot for your department we offer multi-user discounts Click the button below to purchase DPlot by credit card now or check the Buy Now page for more information on pricing and payment options

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                                DPlot Graphing Software for Scientists and Engineers - Home Page

                                Current Version (9 December 2007)The latest release version of DPlot is 2149 Check the Revision History page for a list of recent changes Licensed users should sign up for the mailing list to receive instructions for downloading the free upgrade or select Check for Updates on the Help menu within DPlot

                                NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

                                The most recent update includes 2D vector plots and the ability to draw antialiased curves and other graphic objects for more attractive graphs

                                Other ProductsIf you produce graphs with DPlot and would like to distribute them to others youll want to take a look at DPlot Viewer This is a free application that may be distributed to others without charge DPlot Viewer will display andor print any graph produced by DPlot

                                Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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                                DPlot Graphing Software for Scientists and Engineers - Home Page

                                or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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                                Gradually Varied Flow Calculation Backwater profile

                                bull

                                Gradually Varied Flow in Trapezoidal Channel

                                Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                                Compute normal and critical depths

                                To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                                LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                                Cross-Section of Trapezoidal Channel

                                Gradually Varied Flow Profiles

                                CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                                middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                                Gradually Varied Flow Calculation Backwater profile

                                Links on this page Equations Variables Manning n coefficients Error messages References

                                Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                                equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                                calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                                The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                                Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                                using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                                References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                                empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                                Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                                Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                                1985) along with the fundamental equations above to solve for Yc

                                Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                                the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                                Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                                critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                                For mild slopes (YngtYc)

                                If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                water depth gets closer to Yn as the calculation proceeds further and further upstream

                                If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                                Gradually Varied Flow Calculation Backwater profile

                                The water depth gets closer to Yn as the calculation proceeds further and further upstream

                                If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                                is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                For steep slopes (YcgtYn)

                                If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                                is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                water depth gets closer to Yn as the calculation proceeds further and further downstream

                                If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                water depth gets closer to Yn as the calculation proceeds further and further downstream

                                For critical slopes (Yc=Yn)

                                If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                water depth gets closer to Yn as the calculation proceeds further and further upstream

                                If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                water depth gets closer to Yn as the calculation proceeds further and further downstream

                                There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                                Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                                At control section i=1 and Yi=Ys

                                Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                                Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                                Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                                P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                                differential depth increments (this is the basis of the Improved Euler method)

                                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                                Gradually Varied Flow Calculation Backwater profile

                                Then repeat the loop by incrementing i

                                The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                Ap=Area at Xp [m2]

                                A2=Area for intermediate computation in Improved Euler method [m2]

                                dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                (dYdX)2=Second depth increment for Improved Euler method [m]

                                B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                Epy=Elevation of water surface at Xp [m]

                                F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                P2=Second wetted perimeter computed in Improved Euler method [m]

                                Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                Sf1=First energy slope for Improved Euler method [dimensionless]

                                Sf2=Second energy slope for Improved Euler method [dimensionless]

                                T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                T2=Second top width computed in Improved Euler method [m]

                                Tp=Top width at Xp [m]

                                V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                automatically set Xp to Xmax

                                Y=Water depth [m]Yc=Critical depth [m]

                                Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                Yn=Normal depth [m]

                                Yp=Depth at Xp [m]

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                                Gradually Varied Flow Calculation Backwater profile

                                Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                Y2=Second depth computed in Improved Euler method [m]

                                Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                Material Manning n Material Manning n

                                Natural Streams Excavated Earth Channels

                                Clean and Straight 0030 Clean 0022

                                Major Rivers 0035 Gravelly 0025

                                Sluggish with Deep Pools 0040 Weedy 0030

                                Stony Cobbles 0035

                                Metals Floodplains

                                Brass 0011 Pasture Farmland 0035

                                Cast Iron 0013 Light Brush 0050

                                Smooth Steel 0012 Heavy Brush 0075

                                Corrugated Metal 0022 Trees 015

                                Non-Metals

                                Glass 0010 Finished Concrete 0012

                                Clay Tile 0014 Unfinished Concrete 0014

                                Brickwork 0015 Gravel 0029

                                Asphalt 0016 Earth 0025

                                Masonry 0025 Planed Wood 0012

                                Unplaned Wood 0013

                                Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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                                Gradually Varied Flow Calculation Backwater profile

                                Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                LMNOLMNOengcom httpwwwlmnoengcom

                                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                Hydraulic Jump Calculation

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                                Hydraulic Jump in Horizontal Rectangular Channel

                                Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                jump length and energy loss

                                To LMNO Engineering home page (all calculations) Related open channel calculations

                                Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                Hydraulic Jump Calculation

                                Register to enable Calculate button

                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                Equations

                                Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                What is a Hydraulic Jump

                                A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                                Hydraulic Jump Calculation

                                MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                Need F1 gt1 Upstream flow must be supercritical

                                ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                LMNOLMNOengcom httpwwwlmnoengcom

                                fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                Manning Equation

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                                Mannings Equation Calculator Software The open channel flow software website

                                LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                The product AP is also known as the hydraulic radius Rh

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                                Non-Circular Open Channel Geometry

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                                Geometric Calculations for Non-Circular Partially Filled Channels

                                The open channel flow calculations software website

                                Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                Equations (note that R=AP)

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                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                losses

                                Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                pipe Dont have to use all the pipes or nodes

                                To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                Register to fully enable Calculate button

                                Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                Pipe flows are adjusted iteratively using the following equation

                                until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                LMNOLMNOengcom httpwwwlmnoengcom

                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                                Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                Weisbach - Moody friction losses)

                                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                Parabolic shaped pump curve is formed from the two points

                                ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                curve Hazen-Williams with pump curve

                                Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                Register to enable Calculate button

                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                calculation will look like

                                The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                defined for liquids

                                Variables Units F=force L=length P=pressure T=time Back to Calculations

                                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                hf = Major losses for entire pipe [L] Also known as friction losses

                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                hm = Minor losses for entire pipe [L]

                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                Fitting K Fitting K

                                Valves Elbows

                                Globe fully open 10 Regular 90deg flanged 03

                                Angle fully open 2 Regular 90deg threaded 15

                                Gate fully open 015 Long radius 90deg flanged 02

                                Gate 14 closed 026 Long radius 90deg threaded 07

                                Gate 12 closed 21 Long radius 45deg threaded 02

                                Gate 34 closed 17 Regular 45deg threaded 04

                                Swing check forward flow 2

                                Swing check backward flow infinity Tees

                                Line flow flanged 02

                                180deg return bends Line flow threaded 09

                                Flanged 02 Branch flow flanged 10

                                Threaded 15 Branch flow threaded 20

                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                Square Connection 05 Square Connection 10

                                Rounded Connection 02 Rounded Connection 10

                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                the pipe or K for the suction pipe was entered as greater than K for the entire system

                                Other messagesK must be gt=1 If Q known Solve for D and V

                                3=0 then K must be gt 1 in order to solve

                                Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                reservoirs are defined to be at zero pressure thus zero pressure difference

                                Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                LMNOLMNOengcom httpwwwlmnoengcom

                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                Circular Pressurized Water Pipes with Pump Curve

                                (Hazen Williams)

                                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                curve Darcy-Weisbach with pump curve

                                Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                Register to enable Calculate button

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                                Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                Equations and Methodology Back to Calculations

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                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                calculation will look like

                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                Variables Units L=length P=pressure T=time Back to Calculations

                                A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                hf = Major losses for entire pipe [L]

                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                hm = Minor losses for entire pipe [L]

                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                Material C Material C

                                Asbestos Cement 140 Copper 130-140

                                Brass 130-140 Galvanized iron 120

                                Brick sewer 100 Glass 140

                                Cast-Iron Lead 130-140

                                New unlined 130 Plastic 140-150

                                10 yr old 107-113 Steel

                                20 yr old 89-100 Coal-tar enamel lined 145-150

                                30 yr old 75-90 New unlined 140-150

                                40 yr old 64-83 Riveted 110

                                ConcreteConcrete-lined

                                Steel forms 140 Tin 130

                                Wooden forms 120 Vitrif clay (good condition) 110-140

                                Centrifugally spun 135 Wood stave (avg condition) 120

                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                Fitting K Fitting K

                                Valves Elbows

                                Globe fully open 10 Regular 90deg flanged 03

                                Angle fully open 2 Regular 90deg threaded 15

                                Gate fully open 015 Long radius 90deg flanged 02

                                Gate 14 closed 026 Long radius 90deg threaded 07

                                Gate 12 closed 21 Long radius 45deg threaded 02

                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                Gate 34 closed 17 Regular 45deg threaded 04

                                Swing check forward flow 2

                                Swing check backward flow infinity Tees

                                Line flow flanged 02

                                180deg return bends Line flow threaded 09

                                Flanged 02 Branch flow flanged 10

                                Threaded 15 Branch flow threaded 20

                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                Square Connection 05 Square Connection 10

                                Rounded Connection 02 Rounded Connection 10

                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                LMNOLMNOengcom httpwwwlmnoengcom

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                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                Trapezoidal Open Channel Design Calculation

                                Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                Froude number Manning coefficient channel slope

                                To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                Links on this page Introduction Variables Manning n coefficients Error Messages References

                                IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                Variables [] indicates dimensions To calculation

                                A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                divided by vertical distance

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                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                Oslash = Angle formed by S

                                Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                Material Manning n Material Manning n

                                Natural Streams Excavated Earth Channels

                                Clean and Straight 0030 Clean 0022

                                Major Rivers 0035 Gravelly 0025

                                Sluggish with Deep Pools 0040 Weedy 0030

                                Stony Cobbles 0035

                                Metals Floodplains

                                Brass 0011 Pasture Farmland 0035

                                Cast Iron 0013 Light Brush 0050

                                Smooth Steel 0012 Heavy Brush 0075

                                Corrugated Metal 0022 Trees 015

                                Non-Metals

                                Glass 0010 Finished Concrete 0012

                                Clay Tile 0014 Unfinished Concrete 0014

                                Brickwork 0015 Gravel 0029

                                Asphalt 0016 Earth 0025

                                Masonry 0025 Planed Wood 0012

                                Unplaned Wood 0013

                                Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

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                                Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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                                copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                  • Local Disk
                                    • Circular Culvert Design Calculations Software Equations
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                                            • Culvert Design Inlet and Outlet Control
                                                • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                    • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                            • Hydraulic Jump Calculation
                                                                                • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                    • Manning Equation
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                                                                                                • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                    • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                        • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                            • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                    • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                        • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                            • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                    • Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                  Compatible with Windowsreg 95 98 2000 ME NT 2003 XP and Vista

                                  DPlot graphs and manipulates 2D and 3D data from a variety of sources in many different formats While designed for scientists engineers and other technical fields DPlots straightforward interface will appeal to anybody interested in creating presentation-quality X-Y plots andor contour plots of 3D data DPlot runs on Windows 95 98 2000 ME NT 2003 XP and Vista

                                  You can buy a single-user DPlot license for $45(US) or $55 for a CD sent by mail If you buy DPlot for your department we offer multi-user discounts Click the button below to purchase DPlot by credit card now or check the Buy Now page for more information on pricing and payment options

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                                  Current Version (9 December 2007)The latest release version of DPlot is 2149 Check the Revision History page for a list of recent changes Licensed users should sign up for the mailing list to receive instructions for downloading the free upgrade or select Check for Updates on the Help menu within DPlot

                                  NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

                                  The most recent update includes 2D vector plots and the ability to draw antialiased curves and other graphic objects for more attractive graphs

                                  Other ProductsIf you produce graphs with DPlot and would like to distribute them to others youll want to take a look at DPlot Viewer This is a free application that may be distributed to others without charge DPlot Viewer will display andor print any graph produced by DPlot

                                  Programmers should be sure to check out DPlot Jr a free scaled-down version of DPlot DPlot Jr is intended for use by those that want a quick method for displaying graphical output of their own applications Unlike the full version of DPlot DPlot Jr may be redistributed to end users without royalty payments

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                                  or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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                                  Gradually Varied Flow Calculation Backwater profile

                                  bull

                                  Gradually Varied Flow in Trapezoidal Channel

                                  Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                                  Compute normal and critical depths

                                  To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                                  LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                                  Cross-Section of Trapezoidal Channel

                                  Gradually Varied Flow Profiles

                                  CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                                  middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                                  Gradually Varied Flow Calculation Backwater profile

                                  Links on this page Equations Variables Manning n coefficients Error messages References

                                  Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                                  equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                                  calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                                  The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                                  Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                                  using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                                  References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                                  empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                                  Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                                  Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                                  1985) along with the fundamental equations above to solve for Yc

                                  Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                                  the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                                  Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                                  critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                                  For mild slopes (YngtYc)

                                  If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                  water depth gets closer to Yn as the calculation proceeds further and further upstream

                                  If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                                  Gradually Varied Flow Calculation Backwater profile

                                  The water depth gets closer to Yn as the calculation proceeds further and further upstream

                                  If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                                  is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                  For steep slopes (YcgtYn)

                                  If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                                  is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                  If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                  water depth gets closer to Yn as the calculation proceeds further and further downstream

                                  If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                  water depth gets closer to Yn as the calculation proceeds further and further downstream

                                  For critical slopes (Yc=Yn)

                                  If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                  water depth gets closer to Yn as the calculation proceeds further and further upstream

                                  If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                  water depth gets closer to Yn as the calculation proceeds further and further downstream

                                  There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                                  Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                                  At control section i=1 and Yi=Ys

                                  Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                                  Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                                  Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                                  P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                                  differential depth increments (this is the basis of the Improved Euler method)

                                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                                  Gradually Varied Flow Calculation Backwater profile

                                  Then repeat the loop by incrementing i

                                  The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                  Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                  Ap=Area at Xp [m2]

                                  A2=Area for intermediate computation in Improved Euler method [m2]

                                  dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                  (dYdX)2=Second depth increment for Improved Euler method [m]

                                  B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                  Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                  Epy=Elevation of water surface at Xp [m]

                                  F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                  g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                  P2=Second wetted perimeter computed in Improved Euler method [m]

                                  Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                  Sf1=First energy slope for Improved Euler method [dimensionless]

                                  Sf2=Second energy slope for Improved Euler method [dimensionless]

                                  T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                  T2=Second top width computed in Improved Euler method [m]

                                  Tp=Top width at Xp [m]

                                  V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                  X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                  is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                  Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                  automatically set Xp to Xmax

                                  Y=Water depth [m]Yc=Critical depth [m]

                                  Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                  Yn=Normal depth [m]

                                  Yp=Depth at Xp [m]

                                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

                                  Gradually Varied Flow Calculation Backwater profile

                                  Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                  Y2=Second depth computed in Improved Euler method [m]

                                  Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                  Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                  Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                  Material Manning n Material Manning n

                                  Natural Streams Excavated Earth Channels

                                  Clean and Straight 0030 Clean 0022

                                  Major Rivers 0035 Gravelly 0025

                                  Sluggish with Deep Pools 0040 Weedy 0030

                                  Stony Cobbles 0035

                                  Metals Floodplains

                                  Brass 0011 Pasture Farmland 0035

                                  Cast Iron 0013 Light Brush 0050

                                  Smooth Steel 0012 Heavy Brush 0075

                                  Corrugated Metal 0022 Trees 015

                                  Non-Metals

                                  Glass 0010 Finished Concrete 0012

                                  Clay Tile 0014 Unfinished Concrete 0014

                                  Brickwork 0015 Gravel 0029

                                  Asphalt 0016 Earth 0025

                                  Masonry 0025 Planed Wood 0012

                                  Unplaned Wood 0013

                                  Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                  20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                  Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                  Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                  is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                  References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                  Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                                  Gradually Varied Flow Calculation Backwater profile

                                  Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                  French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                  Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                  Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                  Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                  Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                  copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                  LMNOLMNOengcom httpwwwlmnoengcom

                                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                  Hydraulic Jump Calculation

                                  bull

                                  Hydraulic Jump in Horizontal Rectangular Channel

                                  Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                  jump length and energy loss

                                  To LMNO Engineering home page (all calculations) Related open channel calculations

                                  Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                  Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                  Hydraulic Jump Calculation

                                  Register to enable Calculate button

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  Equations

                                  Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                  V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                  L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                  where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                  Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                  What is a Hydraulic Jump

                                  A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                  According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                  oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                  occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                                  Hydraulic Jump Calculation

                                  MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                  Need F1 gt1 Upstream flow must be supercritical

                                  ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                  copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                  LMNOLMNOengcom httpwwwlmnoengcom

                                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                  Manning Equation

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                                  Mannings Equation Calculator Software The open channel flow software website

                                  LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                  Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                  and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                  The product AP is also known as the hydraulic radius Rh

                                  fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                  Non-Circular Open Channel Geometry

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                                  Geometric Calculations for Non-Circular Partially Filled Channels

                                  The open channel flow calculations software website

                                  Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                  Equations (note that R=AP)

                                  fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                  Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                  losses

                                  Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                  pipe Dont have to use all the pipes or nodes

                                  To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                  Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                  Register to fully enable Calculate button

                                  Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                  IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                  Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                  The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                  Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                  Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                  1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                  Pipe flows are adjusted iteratively using the following equation

                                  until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                  Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                  Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                  Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                  where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                  Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                  Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                  Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                  Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                  The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                  ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                  1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                  pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                  2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                  Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                  Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                  Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                  A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                  n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                  Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                  Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                  References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                  Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                  LMNOLMNOengcom httpwwwlmnoengcom

                                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                                  Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                  Weisbach - Moody friction losses)

                                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                  (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                  Parabolic shaped pump curve is formed from the two points

                                  ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                  curve Hazen-Williams with pump curve

                                  Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                  Register to enable Calculate button

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                  IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                  A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                  For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                  (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                  Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                  Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                  calculation will look like

                                  The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                  Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                  Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                  is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                  defined for liquids

                                  Variables Units F=force L=length P=pressure T=time Back to Calculations

                                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                  is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                  A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                  hf = Major losses for entire pipe [L] Also known as friction losses

                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                  hm = Minor losses for entire pipe [L]

                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                  K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                  for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                  P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                  location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                  zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                  V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                  this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                  v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                  Fitting K Fitting K

                                  Valves Elbows

                                  Globe fully open 10 Regular 90deg flanged 03

                                  Angle fully open 2 Regular 90deg threaded 15

                                  Gate fully open 015 Long radius 90deg flanged 02

                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                  Gate 12 closed 21 Long radius 45deg threaded 02

                                  Gate 34 closed 17 Regular 45deg threaded 04

                                  Swing check forward flow 2

                                  Swing check backward flow infinity Tees

                                  Line flow flanged 02

                                  180deg return bends Line flow threaded 09

                                  Flanged 02 Branch flow flanged 10

                                  Threaded 15 Branch flow threaded 20

                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                  Square Connection 05 Square Connection 10

                                  Rounded Connection 02 Rounded Connection 10

                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                  Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                  The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                  Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                  the pipe or K for the suction pipe was entered as greater than K for the entire system

                                  Other messagesK must be gt=1 If Q known Solve for D and V

                                  3=0 then K must be gt 1 in order to solve

                                  Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                  reservoirs are defined to be at zero pressure thus zero pressure difference

                                  Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                  Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                  References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                  Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                  Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                  Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                  Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                  White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                  LMNOLMNOengcom httpwwwlmnoengcom

                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  bull

                                  Circular Pressurized Water Pipes with Pump Curve

                                  (Hazen Williams)

                                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                  (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                  temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                  ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                  curve Darcy-Weisbach with pump curve

                                  Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                  Register to enable Calculate button

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                  IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                  function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                  manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                  Equations and Methodology Back to Calculations

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                  calculation will look like

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                  Variables Units L=length P=pressure T=time Back to Calculations

                                  A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                  g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                  hf = Major losses for entire pipe [L]

                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                  hm = Minor losses for entire pipe [L]

                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                  k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                  L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                  program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                  location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                  zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                  this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                  Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                  available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                  and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                  Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                  Material C Material C

                                  Asbestos Cement 140 Copper 130-140

                                  Brass 130-140 Galvanized iron 120

                                  Brick sewer 100 Glass 140

                                  Cast-Iron Lead 130-140

                                  New unlined 130 Plastic 140-150

                                  10 yr old 107-113 Steel

                                  20 yr old 89-100 Coal-tar enamel lined 145-150

                                  30 yr old 75-90 New unlined 140-150

                                  40 yr old 64-83 Riveted 110

                                  ConcreteConcrete-lined

                                  Steel forms 140 Tin 130

                                  Wooden forms 120 Vitrif clay (good condition) 110-140

                                  Centrifugally spun 135 Wood stave (avg condition) 120

                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                  Fitting K Fitting K

                                  Valves Elbows

                                  Globe fully open 10 Regular 90deg flanged 03

                                  Angle fully open 2 Regular 90deg threaded 15

                                  Gate fully open 015 Long radius 90deg flanged 02

                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                  Gate 12 closed 21 Long radius 45deg threaded 02

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  Gate 34 closed 17 Regular 45deg threaded 04

                                  Swing check forward flow 2

                                  Swing check backward flow infinity Tees

                                  Line flow flanged 02

                                  180deg return bends Line flow threaded 09

                                  Flanged 02 Branch flow flanged 10

                                  Threaded 15 Branch flow threaded 20

                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                  Square Connection 05 Square Connection 10

                                  Rounded Connection 02 Rounded Connection 10

                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                  Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                  entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                  One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                  entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                  P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                  to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                  the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                  and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                  pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                  result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                  be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                  lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                  LMNOLMNOengcom httpwwwlmnoengcom

                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                  bull

                                  Trapezoidal Open Channel Design Calculation

                                  Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                  Froude number Manning coefficient channel slope

                                  To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                  Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                  Register to enable Calculate button

                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                  Links on this page Introduction Variables Manning n coefficients Error Messages References

                                  IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                  beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                  The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                  In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                  Variables [] indicates dimensions To calculation

                                  A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                  divided by vertical distance

                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                  Oslash = Angle formed by S

                                  Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                  Material Manning n Material Manning n

                                  Natural Streams Excavated Earth Channels

                                  Clean and Straight 0030 Clean 0022

                                  Major Rivers 0035 Gravelly 0025

                                  Sluggish with Deep Pools 0040 Weedy 0030

                                  Stony Cobbles 0035

                                  Metals Floodplains

                                  Brass 0011 Pasture Farmland 0035

                                  Cast Iron 0013 Light Brush 0050

                                  Smooth Steel 0012 Heavy Brush 0075

                                  Corrugated Metal 0022 Trees 015

                                  Non-Metals

                                  Glass 0010 Finished Concrete 0012

                                  Clay Tile 0014 Unfinished Concrete 0014

                                  Brickwork 0015 Gravel 0029

                                  Asphalt 0016 Earth 0025

                                  Masonry 0025 Planed Wood 0012

                                  Unplaned Wood 0013

                                  Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                  Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                  Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                  Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                  The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                  cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                  simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                  The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                  References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                  a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                  c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                  e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                  Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                  French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                  d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                  Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                  b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                  7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                  Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                  Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                  View the version 40 New Features List

                                  Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                  AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                  fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                  components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                  From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                  View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                  Learn More About AFT Impulse 40

                                  Details Views Brochure Demo

                                  copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                    • Local Disk
                                      • Circular Culvert Design Calculations Software Equations
                                          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                            • Local Disk
                                              • Culvert Design Inlet and Outlet Control
                                                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                    • Local Disk
                                                      • Design of Circular Water Pipes using Hazen Williams Equation
                                                          • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                            • Local Disk
                                                              • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                  • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                    • Local Disk
                                                                      • Gradually Varied Flow Calculation Backwater profile
                                                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                            • Local Disk
                                                                              • Hydraulic Jump Calculation
                                                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                    • Local Disk
                                                                                      • Manning Equation
                                                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                            • Local Disk
                                                                                              • Non-Circular Open Channel Geometry
                                                                                                  • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                    • Local Disk
                                                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                            • Local Disk
                                                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                    • Local Disk
                                                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                            • Local Disk
                                                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                    • Local Disk
                                                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                    DPlot Graphing Software for Scientists and Engineers - Home Page

                                    Current Version (9 December 2007)The latest release version of DPlot is 2149 Check the Revision History page for a list of recent changes Licensed users should sign up for the mailing list to receive instructions for downloading the free upgrade or select Check for Updates on the Help menu within DPlot

                                    NewsThe DPlot download includes an Add-In for Microsoft Excel that makes moving data in a variety of layouts from Excel to DPlot a snap The functions included in the Add-In might also give developers ideas for their own VBA solutions We think youll find this new feature very useful Your comments and suggestions are welcome

                                    The most recent update includes 2D vector plots and the ability to draw antialiased curves and other graphic objects for more attractive graphs

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                                    DPlot Graphing Software for Scientists and Engineers - Home Page

                                    or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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                                    Gradually Varied Flow Calculation Backwater profile

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                                    Gradually Varied Flow in Trapezoidal Channel

                                    Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                                    Compute normal and critical depths

                                    To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                                    LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                                    Cross-Section of Trapezoidal Channel

                                    Gradually Varied Flow Profiles

                                    CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                                    middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                                    fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                                    Gradually Varied Flow Calculation Backwater profile

                                    Links on this page Equations Variables Manning n coefficients Error messages References

                                    Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                                    equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                                    calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                                    The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                                    Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                                    using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                                    References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                                    empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                                    Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                                    Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                                    1985) along with the fundamental equations above to solve for Yc

                                    Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                                    the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                                    Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                                    critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                                    For mild slopes (YngtYc)

                                    If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                    water depth gets closer to Yn as the calculation proceeds further and further upstream

                                    If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

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                                    Gradually Varied Flow Calculation Backwater profile

                                    The water depth gets closer to Yn as the calculation proceeds further and further upstream

                                    If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                                    is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                    For steep slopes (YcgtYn)

                                    If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                                    is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                    If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                    water depth gets closer to Yn as the calculation proceeds further and further downstream

                                    If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                    water depth gets closer to Yn as the calculation proceeds further and further downstream

                                    For critical slopes (Yc=Yn)

                                    If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                    water depth gets closer to Yn as the calculation proceeds further and further upstream

                                    If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                    water depth gets closer to Yn as the calculation proceeds further and further downstream

                                    There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                                    Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                                    At control section i=1 and Yi=Ys

                                    Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                                    Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                                    Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                                    P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                                    differential depth increments (this is the basis of the Improved Euler method)

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                                    Gradually Varied Flow Calculation Backwater profile

                                    Then repeat the loop by incrementing i

                                    The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                    Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                    Ap=Area at Xp [m2]

                                    A2=Area for intermediate computation in Improved Euler method [m2]

                                    dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                    (dYdX)2=Second depth increment for Improved Euler method [m]

                                    B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                    Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                    Epy=Elevation of water surface at Xp [m]

                                    F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                    g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                    P2=Second wetted perimeter computed in Improved Euler method [m]

                                    Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                    Sf1=First energy slope for Improved Euler method [dimensionless]

                                    Sf2=Second energy slope for Improved Euler method [dimensionless]

                                    T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                    T2=Second top width computed in Improved Euler method [m]

                                    Tp=Top width at Xp [m]

                                    V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                    X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                    is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                    Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                    automatically set Xp to Xmax

                                    Y=Water depth [m]Yc=Critical depth [m]

                                    Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                    Yn=Normal depth [m]

                                    Yp=Depth at Xp [m]

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                                    Gradually Varied Flow Calculation Backwater profile

                                    Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                    Y2=Second depth computed in Improved Euler method [m]

                                    Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                    Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                    Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                    Material Manning n Material Manning n

                                    Natural Streams Excavated Earth Channels

                                    Clean and Straight 0030 Clean 0022

                                    Major Rivers 0035 Gravelly 0025

                                    Sluggish with Deep Pools 0040 Weedy 0030

                                    Stony Cobbles 0035

                                    Metals Floodplains

                                    Brass 0011 Pasture Farmland 0035

                                    Cast Iron 0013 Light Brush 0050

                                    Smooth Steel 0012 Heavy Brush 0075

                                    Corrugated Metal 0022 Trees 015

                                    Non-Metals

                                    Glass 0010 Finished Concrete 0012

                                    Clay Tile 0014 Unfinished Concrete 0014

                                    Brickwork 0015 Gravel 0029

                                    Asphalt 0016 Earth 0025

                                    Masonry 0025 Planed Wood 0012

                                    Unplaned Wood 0013

                                    Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                    20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                    Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                    Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                    is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                    References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                    Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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                                    Gradually Varied Flow Calculation Backwater profile

                                    Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                    French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                    Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                    Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                    Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                    Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                    copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                    LMNOLMNOengcom httpwwwlmnoengcom

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                                    Hydraulic Jump Calculation

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                                    Hydraulic Jump in Horizontal Rectangular Channel

                                    Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                    jump length and energy loss

                                    To LMNO Engineering home page (all calculations) Related open channel calculations

                                    Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                    Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                    fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                    Hydraulic Jump Calculation

                                    Register to enable Calculate button

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    Equations

                                    Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                    V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                    L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                    where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                    Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                    What is a Hydraulic Jump

                                    A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                    According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                    oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                    occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                                    Hydraulic Jump Calculation

                                    MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                    Need F1 gt1 Upstream flow must be supercritical

                                    ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                    copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                    LMNOLMNOengcom httpwwwlmnoengcom

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                                    Manning Equation

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                                    Mannings Equation Calculator Software The open channel flow software website

                                    LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                    Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                    and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                    The product AP is also known as the hydraulic radius Rh

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                                    Non-Circular Open Channel Geometry

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                                    Geometric Calculations for Non-Circular Partially Filled Channels

                                    The open channel flow calculations software website

                                    Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                    Equations (note that R=AP)

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                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                    Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                    losses

                                    Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                    pipe Dont have to use all the pipes or nodes

                                    To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                    Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                    Register to fully enable Calculate button

                                    Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                    IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                    Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                    The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                    Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                    Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                    1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                    Pipe flows are adjusted iteratively using the following equation

                                    until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                    Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                    Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                    Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                    where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                    Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                    Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                    Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                    Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                    The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                    ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                    1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                    pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                    2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                    Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                    Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                    Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                    A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                    n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                    Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                    Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                    References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                    Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                    LMNOLMNOengcom httpwwwlmnoengcom

                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    bull

                                    Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                    Weisbach - Moody friction losses)

                                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                    (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                    Parabolic shaped pump curve is formed from the two points

                                    ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                    curve Hazen-Williams with pump curve

                                    Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                    Register to enable Calculate button

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                    IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                    A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                    For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                    (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                    Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                    calculation will look like

                                    The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                    Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                    Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                    is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                    defined for liquids

                                    Variables Units F=force L=length P=pressure T=time Back to Calculations

                                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                    A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                    hf = Major losses for entire pipe [L] Also known as friction losses

                                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                    hm = Minor losses for entire pipe [L]

                                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                    K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                    for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                    P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                    location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                    zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                    this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                    v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                    Fitting K Fitting K

                                    Valves Elbows

                                    Globe fully open 10 Regular 90deg flanged 03

                                    Angle fully open 2 Regular 90deg threaded 15

                                    Gate fully open 015 Long radius 90deg flanged 02

                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                    Gate 34 closed 17 Regular 45deg threaded 04

                                    Swing check forward flow 2

                                    Swing check backward flow infinity Tees

                                    Line flow flanged 02

                                    180deg return bends Line flow threaded 09

                                    Flanged 02 Branch flow flanged 10

                                    Threaded 15 Branch flow threaded 20

                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    Square Connection 05 Square Connection 10

                                    Rounded Connection 02 Rounded Connection 10

                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                    Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                    The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                    Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                    the pipe or K for the suction pipe was entered as greater than K for the entire system

                                    Other messagesK must be gt=1 If Q known Solve for D and V

                                    3=0 then K must be gt 1 in order to solve

                                    Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                    reservoirs are defined to be at zero pressure thus zero pressure difference

                                    Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                    Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                    References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                    Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                    Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                    Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                    Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                    White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                    LMNOLMNOengcom httpwwwlmnoengcom

                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    bull

                                    Circular Pressurized Water Pipes with Pump Curve

                                    (Hazen Williams)

                                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                    (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                    ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                    curve Darcy-Weisbach with pump curve

                                    Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                    Register to enable Calculate button

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                    IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                    function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                    manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                    Equations and Methodology Back to Calculations

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                    calculation will look like

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                    Variables Units L=length P=pressure T=time Back to Calculations

                                    A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                    g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                    hf = Major losses for entire pipe [L]

                                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                    hm = Minor losses for entire pipe [L]

                                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                    k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                    L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                    program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                    location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                    zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                    this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                    Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                    available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                    and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                    Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                    Material C Material C

                                    Asbestos Cement 140 Copper 130-140

                                    Brass 130-140 Galvanized iron 120

                                    Brick sewer 100 Glass 140

                                    Cast-Iron Lead 130-140

                                    New unlined 130 Plastic 140-150

                                    10 yr old 107-113 Steel

                                    20 yr old 89-100 Coal-tar enamel lined 145-150

                                    30 yr old 75-90 New unlined 140-150

                                    40 yr old 64-83 Riveted 110

                                    ConcreteConcrete-lined

                                    Steel forms 140 Tin 130

                                    Wooden forms 120 Vitrif clay (good condition) 110-140

                                    Centrifugally spun 135 Wood stave (avg condition) 120

                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                    Fitting K Fitting K

                                    Valves Elbows

                                    Globe fully open 10 Regular 90deg flanged 03

                                    Angle fully open 2 Regular 90deg threaded 15

                                    Gate fully open 015 Long radius 90deg flanged 02

                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    Gate 34 closed 17 Regular 45deg threaded 04

                                    Swing check forward flow 2

                                    Swing check backward flow infinity Tees

                                    Line flow flanged 02

                                    180deg return bends Line flow threaded 09

                                    Flanged 02 Branch flow flanged 10

                                    Threaded 15 Branch flow threaded 20

                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                    Square Connection 05 Square Connection 10

                                    Rounded Connection 02 Rounded Connection 10

                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                    Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                    entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                    One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                    entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                    P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                    to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                    the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                    and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                    pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                    result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                    be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                    lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                    LMNOLMNOengcom httpwwwlmnoengcom

                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                    bull

                                    Trapezoidal Open Channel Design Calculation

                                    Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                    Froude number Manning coefficient channel slope

                                    To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                    Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                    Register to enable Calculate button

                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                    Links on this page Introduction Variables Manning n coefficients Error Messages References

                                    IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                    beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                    The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                    Variables [] indicates dimensions To calculation

                                    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                    divided by vertical distance

                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                    Oslash = Angle formed by S

                                    Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                    Material Manning n Material Manning n

                                    Natural Streams Excavated Earth Channels

                                    Clean and Straight 0030 Clean 0022

                                    Major Rivers 0035 Gravelly 0025

                                    Sluggish with Deep Pools 0040 Weedy 0030

                                    Stony Cobbles 0035

                                    Metals Floodplains

                                    Brass 0011 Pasture Farmland 0035

                                    Cast Iron 0013 Light Brush 0050

                                    Smooth Steel 0012 Heavy Brush 0075

                                    Corrugated Metal 0022 Trees 015

                                    Non-Metals

                                    Glass 0010 Finished Concrete 0012

                                    Clay Tile 0014 Unfinished Concrete 0014

                                    Brickwork 0015 Gravel 0029

                                    Asphalt 0016 Earth 0025

                                    Masonry 0025 Planed Wood 0012

                                    Unplaned Wood 0013

                                    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                    Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                    The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                    cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                    simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                    The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                    References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                    a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                    Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                    French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                    Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                    7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                    Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                    View the version 40 New Features List

                                    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                    Learn More About AFT Impulse 40

                                    Details Views Brochure Demo

                                    copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                        • Circular Culvert Design Calculations Software Equations
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                                                • Culvert Design Inlet and Outlet Control
                                                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                        • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                        • Gradually Varied Flow Calculation Backwater profile
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                                                                                • Hydraulic Jump Calculation
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                                                                                        • Manning Equation
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                                                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                            • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                      DPlot Graphing Software for Scientists and Engineers - Home Page

                                      or other restrictions Theres nothing to buy and no registration fee involved The latest version of DPlot Jr is distributed with the DPLOTLIB DLL which makes it exceptionally easy to plot data from a variety of languages and environments The distribution includes examples in C C Visual Basic VBNET PowerBasic FreeBASIC and several varieties of FORTRAN

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                                      Gradually Varied Flow Calculation Backwater profile

                                      bull

                                      Gradually Varied Flow in Trapezoidal Channel

                                      Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                                      Compute normal and critical depths

                                      To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                                      LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                                      Cross-Section of Trapezoidal Channel

                                      Gradually Varied Flow Profiles

                                      CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                      middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                                      middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

                                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (1 of 6)12112007 40539 PM

                                      Gradually Varied Flow Calculation Backwater profile

                                      Links on this page Equations Variables Manning n coefficients Error messages References

                                      Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                                      equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                                      calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                                      The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                                      Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                                      using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                                      References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                                      empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                                      Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                                      Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                                      1985) along with the fundamental equations above to solve for Yc

                                      Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                                      the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                                      Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                                      critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                                      For mild slopes (YngtYc)

                                      If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                      water depth gets closer to Yn as the calculation proceeds further and further upstream

                                      If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                                      Gradually Varied Flow Calculation Backwater profile

                                      The water depth gets closer to Yn as the calculation proceeds further and further upstream

                                      If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                                      is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                      For steep slopes (YcgtYn)

                                      If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                                      is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                      If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                      water depth gets closer to Yn as the calculation proceeds further and further downstream

                                      If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                      water depth gets closer to Yn as the calculation proceeds further and further downstream

                                      For critical slopes (Yc=Yn)

                                      If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                      water depth gets closer to Yn as the calculation proceeds further and further upstream

                                      If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                      water depth gets closer to Yn as the calculation proceeds further and further downstream

                                      There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                                      Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                                      At control section i=1 and Yi=Ys

                                      Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                                      Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                                      Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                                      P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                                      differential depth increments (this is the basis of the Improved Euler method)

                                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                                      Gradually Varied Flow Calculation Backwater profile

                                      Then repeat the loop by incrementing i

                                      The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                      Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                      Ap=Area at Xp [m2]

                                      A2=Area for intermediate computation in Improved Euler method [m2]

                                      dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                      (dYdX)2=Second depth increment for Improved Euler method [m]

                                      B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                      Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                      Epy=Elevation of water surface at Xp [m]

                                      F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                      g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                      P2=Second wetted perimeter computed in Improved Euler method [m]

                                      Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                      Sf1=First energy slope for Improved Euler method [dimensionless]

                                      Sf2=Second energy slope for Improved Euler method [dimensionless]

                                      T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                      T2=Second top width computed in Improved Euler method [m]

                                      Tp=Top width at Xp [m]

                                      V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                      X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                      is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                      Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                      automatically set Xp to Xmax

                                      Y=Water depth [m]Yc=Critical depth [m]

                                      Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                      Yn=Normal depth [m]

                                      Yp=Depth at Xp [m]

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                                      Gradually Varied Flow Calculation Backwater profile

                                      Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                      Y2=Second depth computed in Improved Euler method [m]

                                      Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                      Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                      Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                      Material Manning n Material Manning n

                                      Natural Streams Excavated Earth Channels

                                      Clean and Straight 0030 Clean 0022

                                      Major Rivers 0035 Gravelly 0025

                                      Sluggish with Deep Pools 0040 Weedy 0030

                                      Stony Cobbles 0035

                                      Metals Floodplains

                                      Brass 0011 Pasture Farmland 0035

                                      Cast Iron 0013 Light Brush 0050

                                      Smooth Steel 0012 Heavy Brush 0075

                                      Corrugated Metal 0022 Trees 015

                                      Non-Metals

                                      Glass 0010 Finished Concrete 0012

                                      Clay Tile 0014 Unfinished Concrete 0014

                                      Brickwork 0015 Gravel 0029

                                      Asphalt 0016 Earth 0025

                                      Masonry 0025 Planed Wood 0012

                                      Unplaned Wood 0013

                                      Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                      20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                      Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                      Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                      is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                      References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                      Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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                                      Gradually Varied Flow Calculation Backwater profile

                                      Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                      French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                      Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                      Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                      Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                      Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                      copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                      LMNOLMNOengcom httpwwwlmnoengcom

                                      fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                      Hydraulic Jump Calculation

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                                      Hydraulic Jump in Horizontal Rectangular Channel

                                      Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                      jump length and energy loss

                                      To LMNO Engineering home page (all calculations) Related open channel calculations

                                      Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                      Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                      fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                      Hydraulic Jump Calculation

                                      Register to enable Calculate button

                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                      Equations

                                      Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                      V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                      L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                      where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                      Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                      What is a Hydraulic Jump

                                      A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                      According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                      oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                      occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                                      Hydraulic Jump Calculation

                                      MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                      Need F1 gt1 Upstream flow must be supercritical

                                      ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                      copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                      LMNOLMNOengcom httpwwwlmnoengcom

                                      fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                      Manning Equation

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                                      Mannings Equation Calculator Software The open channel flow software website

                                      LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                      Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                      The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                      and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                      The product AP is also known as the hydraulic radius Rh

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                                      Non-Circular Open Channel Geometry

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                                      Geometric Calculations for Non-Circular Partially Filled Channels

                                      The open channel flow calculations software website

                                      Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                      You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                      Equations (note that R=AP)

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                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                      Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                      losses

                                      Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                      pipe Dont have to use all the pipes or nodes

                                      To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                      Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                      Register to fully enable Calculate button

                                      Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                      Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                      IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                      Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                      The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                      Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                      Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                      1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                      Pipe flows are adjusted iteratively using the following equation

                                      until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                      Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                      Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                      Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                      where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                      Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                      Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                      Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                      Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                      For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                      The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                      ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                      1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                      pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                      2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                      Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                      Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                      Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                      A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                      n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                      Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                      Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                      References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                      Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                      LMNOLMNOengcom httpwwwlmnoengcom

                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                                      Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                      Weisbach - Moody friction losses)

                                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                      (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                      Parabolic shaped pump curve is formed from the two points

                                      ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                      curve Hazen-Williams with pump curve

                                      Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                      Register to enable Calculate button

                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                      Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                      IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                      A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                      For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                      (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                      Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                      Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                      calculation will look like

                                      The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                      Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                      Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                      is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                      defined for liquids

                                      Variables Units F=force L=length P=pressure T=time Back to Calculations

                                      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                      is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                      A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                      hf = Major losses for entire pipe [L] Also known as friction losses

                                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                      hm = Minor losses for entire pipe [L]

                                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                      K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                      for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                      P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                      location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                      zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                      V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                      this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                      v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                      Fitting K Fitting K

                                      Valves Elbows

                                      Globe fully open 10 Regular 90deg flanged 03

                                      Angle fully open 2 Regular 90deg threaded 15

                                      Gate fully open 015 Long radius 90deg flanged 02

                                      Gate 14 closed 026 Long radius 90deg threaded 07

                                      Gate 12 closed 21 Long radius 45deg threaded 02

                                      Gate 34 closed 17 Regular 45deg threaded 04

                                      Swing check forward flow 2

                                      Swing check backward flow infinity Tees

                                      Line flow flanged 02

                                      180deg return bends Line flow threaded 09

                                      Flanged 02 Branch flow flanged 10

                                      Threaded 15 Branch flow threaded 20

                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                      Square Connection 05 Square Connection 10

                                      Rounded Connection 02 Rounded Connection 10

                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                      Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                      The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                      Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                      the pipe or K for the suction pipe was entered as greater than K for the entire system

                                      Other messagesK must be gt=1 If Q known Solve for D and V

                                      3=0 then K must be gt 1 in order to solve

                                      Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                      reservoirs are defined to be at zero pressure thus zero pressure difference

                                      Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                      Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                      References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                      Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                      Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                      Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                      Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                      White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                      LMNOLMNOengcom httpwwwlmnoengcom

                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      bull

                                      Circular Pressurized Water Pipes with Pump Curve

                                      (Hazen Williams)

                                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                      (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                      ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                      curve Darcy-Weisbach with pump curve

                                      Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                      Register to enable Calculate button

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                                      Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                      IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                      function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                      manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                      Equations and Methodology Back to Calculations

                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                      calculation will look like

                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                      Variables Units L=length P=pressure T=time Back to Calculations

                                      A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                      g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                      hf = Major losses for entire pipe [L]

                                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                      hm = Minor losses for entire pipe [L]

                                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                      k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                      L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                      program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                      location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                      zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                      this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                      Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                      available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                      and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                      Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                      Material C Material C

                                      Asbestos Cement 140 Copper 130-140

                                      Brass 130-140 Galvanized iron 120

                                      Brick sewer 100 Glass 140

                                      Cast-Iron Lead 130-140

                                      New unlined 130 Plastic 140-150

                                      10 yr old 107-113 Steel

                                      20 yr old 89-100 Coal-tar enamel lined 145-150

                                      30 yr old 75-90 New unlined 140-150

                                      40 yr old 64-83 Riveted 110

                                      ConcreteConcrete-lined

                                      Steel forms 140 Tin 130

                                      Wooden forms 120 Vitrif clay (good condition) 110-140

                                      Centrifugally spun 135 Wood stave (avg condition) 120

                                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                      Fitting K Fitting K

                                      Valves Elbows

                                      Globe fully open 10 Regular 90deg flanged 03

                                      Angle fully open 2 Regular 90deg threaded 15

                                      Gate fully open 015 Long radius 90deg flanged 02

                                      Gate 14 closed 026 Long radius 90deg threaded 07

                                      Gate 12 closed 21 Long radius 45deg threaded 02

                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      Gate 34 closed 17 Regular 45deg threaded 04

                                      Swing check forward flow 2

                                      Swing check backward flow infinity Tees

                                      Line flow flanged 02

                                      180deg return bends Line flow threaded 09

                                      Flanged 02 Branch flow flanged 10

                                      Threaded 15 Branch flow threaded 20

                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                      Square Connection 05 Square Connection 10

                                      Rounded Connection 02 Rounded Connection 10

                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                      Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                      entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                      One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                      entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                      P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                      to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                      the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                      and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                      pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                      result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                      be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                      lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                      LMNOLMNOengcom httpwwwlmnoengcom

                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                      Trapezoidal Open Channel Design Calculation

                                      Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                      Froude number Manning coefficient channel slope

                                      To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                      Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                      Links on this page Introduction Variables Manning n coefficients Error Messages References

                                      IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                      beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                      The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                      In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                      Variables [] indicates dimensions To calculation

                                      A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                      divided by vertical distance

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                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                      Oslash = Angle formed by S

                                      Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                      Material Manning n Material Manning n

                                      Natural Streams Excavated Earth Channels

                                      Clean and Straight 0030 Clean 0022

                                      Major Rivers 0035 Gravelly 0025

                                      Sluggish with Deep Pools 0040 Weedy 0030

                                      Stony Cobbles 0035

                                      Metals Floodplains

                                      Brass 0011 Pasture Farmland 0035

                                      Cast Iron 0013 Light Brush 0050

                                      Smooth Steel 0012 Heavy Brush 0075

                                      Corrugated Metal 0022 Trees 015

                                      Non-Metals

                                      Glass 0010 Finished Concrete 0012

                                      Clay Tile 0014 Unfinished Concrete 0014

                                      Brickwork 0015 Gravel 0029

                                      Asphalt 0016 Earth 0025

                                      Masonry 0025 Planed Wood 0012

                                      Unplaned Wood 0013

                                      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                      Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                      The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                      cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                      simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                      The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                      References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                      a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                      Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                      French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                      Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                      7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                      Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

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                                      AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

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                                      copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                          • Circular Culvert Design Calculations Software Equations
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                                                                          • Gradually Varied Flow Calculation Backwater profile
                                                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                  • Hydraulic Jump Calculation
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                                                                                          • Manning Equation
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                                                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
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                                                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                • Local Disk
                                                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                        • Local Disk
                                                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                        Gradually Varied Flow Calculation Backwater profile

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                                        Gradually Varied Flow in Trapezoidal Channel

                                        Plot Water depth Velocity Froude Top width vs DistanceCompute GVF profile (M1 M2 S2 S3 C1 C3)

                                        Compute normal and critical depths

                                        To LMNO Engineering home page (more calculations) Trapezoidal Channel Design Hydraulic Jump Unit Conversions

                                        LMNOLMNOengcom phone (USA) +1(740) 592-1890 Trouble printing

                                        Cross-Section of Trapezoidal Channel

                                        Gradually Varied Flow Profiles

                                        CalculationRegister to fully enable the Calculate button Demonstration mode for B=3 m

                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                        middot If x-axis says Distance in m divided by 10^2 then multiply the value shown on the axis by 10^2 in order to get the actual value Therefore 50 on the axis is actually 500 meters Likewise for the y-axismiddot Elevation graph shows bottom of channel (ie channel invert) and water surface elevations relative to channel invert elevation of 00 at Xmax

                                        middot Units cm=centimeter cfs=cubic feet per second ft=feet gpm=US gallons per minute gph=US gallons per hour gpd=US gallons per day km=kilometer m=meter MGD=Millions of US gallons per day s=second

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                                        Gradually Varied Flow Calculation Backwater profile

                                        Links on this page Equations Variables Manning n coefficients Error messages References

                                        Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                                        equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                                        calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                                        The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                                        Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                                        using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                                        References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                                        empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                                        Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                                        Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                                        1985) along with the fundamental equations above to solve for Yc

                                        Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                                        the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                                        Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                                        critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                                        For mild slopes (YngtYc)

                                        If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                        water depth gets closer to Yn as the calculation proceeds further and further upstream

                                        If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                                        Gradually Varied Flow Calculation Backwater profile

                                        The water depth gets closer to Yn as the calculation proceeds further and further upstream

                                        If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                                        is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                        For steep slopes (YcgtYn)

                                        If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                                        is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                        If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                        water depth gets closer to Yn as the calculation proceeds further and further downstream

                                        If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                        water depth gets closer to Yn as the calculation proceeds further and further downstream

                                        For critical slopes (Yc=Yn)

                                        If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                        water depth gets closer to Yn as the calculation proceeds further and further upstream

                                        If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                        water depth gets closer to Yn as the calculation proceeds further and further downstream

                                        There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                                        Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                                        At control section i=1 and Yi=Ys

                                        Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                                        Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                                        Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                                        P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                                        differential depth increments (this is the basis of the Improved Euler method)

                                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                                        Gradually Varied Flow Calculation Backwater profile

                                        Then repeat the loop by incrementing i

                                        The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                        Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                        Ap=Area at Xp [m2]

                                        A2=Area for intermediate computation in Improved Euler method [m2]

                                        dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                        (dYdX)2=Second depth increment for Improved Euler method [m]

                                        B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                        Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                        Epy=Elevation of water surface at Xp [m]

                                        F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                        g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                        P2=Second wetted perimeter computed in Improved Euler method [m]

                                        Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                        Sf1=First energy slope for Improved Euler method [dimensionless]

                                        Sf2=Second energy slope for Improved Euler method [dimensionless]

                                        T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                        T2=Second top width computed in Improved Euler method [m]

                                        Tp=Top width at Xp [m]

                                        V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                        X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                        is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                        Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                        automatically set Xp to Xmax

                                        Y=Water depth [m]Yc=Critical depth [m]

                                        Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                        Yn=Normal depth [m]

                                        Yp=Depth at Xp [m]

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                                        Gradually Varied Flow Calculation Backwater profile

                                        Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                        Y2=Second depth computed in Improved Euler method [m]

                                        Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                        Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                        Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                        Material Manning n Material Manning n

                                        Natural Streams Excavated Earth Channels

                                        Clean and Straight 0030 Clean 0022

                                        Major Rivers 0035 Gravelly 0025

                                        Sluggish with Deep Pools 0040 Weedy 0030

                                        Stony Cobbles 0035

                                        Metals Floodplains

                                        Brass 0011 Pasture Farmland 0035

                                        Cast Iron 0013 Light Brush 0050

                                        Smooth Steel 0012 Heavy Brush 0075

                                        Corrugated Metal 0022 Trees 015

                                        Non-Metals

                                        Glass 0010 Finished Concrete 0012

                                        Clay Tile 0014 Unfinished Concrete 0014

                                        Brickwork 0015 Gravel 0029

                                        Asphalt 0016 Earth 0025

                                        Masonry 0025 Planed Wood 0012

                                        Unplaned Wood 0013

                                        Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                        20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                        Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                        Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                        is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                        References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                        Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                                        Gradually Varied Flow Calculation Backwater profile

                                        Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                        French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                        Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                        Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                        Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                        Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                        copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                        LMNOLMNOengcom httpwwwlmnoengcom

                                        fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                        Hydraulic Jump Calculation

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                                        Hydraulic Jump in Horizontal Rectangular Channel

                                        Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                        jump length and energy loss

                                        To LMNO Engineering home page (all calculations) Related open channel calculations

                                        Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                        Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                        Hydraulic Jump Calculation

                                        Register to enable Calculate button

                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                        Equations

                                        Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                        V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                        L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                        where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                        Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                        What is a Hydraulic Jump

                                        A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                        According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                        oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                        occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                                        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                                        Hydraulic Jump Calculation

                                        MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                        Need F1 gt1 Upstream flow must be supercritical

                                        ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                        copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                        LMNOLMNOengcom httpwwwlmnoengcom

                                        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                        Manning Equation

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                                        Mannings Equation Calculator Software The open channel flow software website

                                        LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                        Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                        The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                        and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                        The product AP is also known as the hydraulic radius Rh

                                        fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                        Non-Circular Open Channel Geometry

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                                        Geometric Calculations for Non-Circular Partially Filled Channels

                                        The open channel flow calculations software website

                                        Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                        You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                        Equations (note that R=AP)

                                        fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                        bull

                                        Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                        losses

                                        Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                        pipe Dont have to use all the pipes or nodes

                                        To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                        Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                        Register to fully enable Calculate button

                                        Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                        Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                        IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                        Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                        The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                        Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                        Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                        1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                        Pipe flows are adjusted iteratively using the following equation

                                        until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                        Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                        Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                        Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                        where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                        Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                        Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                        Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                        Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                        For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                        The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                        ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                        1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                        pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                        2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                        Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                        Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                        Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                        A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                        n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                        Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                        Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                        References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                        Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                        LMNOLMNOengcom httpwwwlmnoengcom

                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        bull

                                        Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                        Weisbach - Moody friction losses)

                                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                        (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                        Parabolic shaped pump curve is formed from the two points

                                        ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                        curve Hazen-Williams with pump curve

                                        Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                        Register to enable Calculate button

                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                        Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                        IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                        A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                        For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                        (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                        Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                        calculation will look like

                                        The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                        Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                        Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                        is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                        defined for liquids

                                        Variables Units F=force L=length P=pressure T=time Back to Calculations

                                        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                        A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                        hf = Major losses for entire pipe [L] Also known as friction losses

                                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                        hm = Minor losses for entire pipe [L]

                                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                        K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                        for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                        P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                        location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                        zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                        this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                        v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                        Fitting K Fitting K

                                        Valves Elbows

                                        Globe fully open 10 Regular 90deg flanged 03

                                        Angle fully open 2 Regular 90deg threaded 15

                                        Gate fully open 015 Long radius 90deg flanged 02

                                        Gate 14 closed 026 Long radius 90deg threaded 07

                                        Gate 12 closed 21 Long radius 45deg threaded 02

                                        Gate 34 closed 17 Regular 45deg threaded 04

                                        Swing check forward flow 2

                                        Swing check backward flow infinity Tees

                                        Line flow flanged 02

                                        180deg return bends Line flow threaded 09

                                        Flanged 02 Branch flow flanged 10

                                        Threaded 15 Branch flow threaded 20

                                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        Square Connection 05 Square Connection 10

                                        Rounded Connection 02 Rounded Connection 10

                                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                        Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                        The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                        Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                        the pipe or K for the suction pipe was entered as greater than K for the entire system

                                        Other messagesK must be gt=1 If Q known Solve for D and V

                                        3=0 then K must be gt 1 in order to solve

                                        Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                        reservoirs are defined to be at zero pressure thus zero pressure difference

                                        Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                        Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                        References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                        Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                        Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                        Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                        Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                        White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        bull

                                        Circular Pressurized Water Pipes with Pump Curve

                                        (Hazen Williams)

                                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                        (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                        ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                        curve Darcy-Weisbach with pump curve

                                        Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

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                                        Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                        IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                        function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                        manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                        Equations and Methodology Back to Calculations

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                        calculation will look like

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                        Variables Units L=length P=pressure T=time Back to Calculations

                                        A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                        g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                        hf = Major losses for entire pipe [L]

                                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                        hm = Minor losses for entire pipe [L]

                                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                        k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                        L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                        program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                        location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                        zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                        this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                        Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                        available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                        and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                        Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                        Material C Material C

                                        Asbestos Cement 140 Copper 130-140

                                        Brass 130-140 Galvanized iron 120

                                        Brick sewer 100 Glass 140

                                        Cast-Iron Lead 130-140

                                        New unlined 130 Plastic 140-150

                                        10 yr old 107-113 Steel

                                        20 yr old 89-100 Coal-tar enamel lined 145-150

                                        30 yr old 75-90 New unlined 140-150

                                        40 yr old 64-83 Riveted 110

                                        ConcreteConcrete-lined

                                        Steel forms 140 Tin 130

                                        Wooden forms 120 Vitrif clay (good condition) 110-140

                                        Centrifugally spun 135 Wood stave (avg condition) 120

                                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                        Fitting K Fitting K

                                        Valves Elbows

                                        Globe fully open 10 Regular 90deg flanged 03

                                        Angle fully open 2 Regular 90deg threaded 15

                                        Gate fully open 015 Long radius 90deg flanged 02

                                        Gate 14 closed 026 Long radius 90deg threaded 07

                                        Gate 12 closed 21 Long radius 45deg threaded 02

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        Gate 34 closed 17 Regular 45deg threaded 04

                                        Swing check forward flow 2

                                        Swing check backward flow infinity Tees

                                        Line flow flanged 02

                                        180deg return bends Line flow threaded 09

                                        Flanged 02 Branch flow flanged 10

                                        Threaded 15 Branch flow threaded 20

                                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                        Square Connection 05 Square Connection 10

                                        Rounded Connection 02 Rounded Connection 10

                                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                        Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                        entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                        One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                        entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                        P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                        to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                        the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                        and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                        pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                        result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                        be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                        lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                        bull

                                        Trapezoidal Open Channel Design Calculation

                                        Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                        Froude number Manning coefficient channel slope

                                        To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                        Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                        Links on this page Introduction Variables Manning n coefficients Error Messages References

                                        IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                        beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                        The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                        In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                        Variables [] indicates dimensions To calculation

                                        A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                        divided by vertical distance

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                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                        Oslash = Angle formed by S

                                        Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                        Material Manning n Material Manning n

                                        Natural Streams Excavated Earth Channels

                                        Clean and Straight 0030 Clean 0022

                                        Major Rivers 0035 Gravelly 0025

                                        Sluggish with Deep Pools 0040 Weedy 0030

                                        Stony Cobbles 0035

                                        Metals Floodplains

                                        Brass 0011 Pasture Farmland 0035

                                        Cast Iron 0013 Light Brush 0050

                                        Smooth Steel 0012 Heavy Brush 0075

                                        Corrugated Metal 0022 Trees 015

                                        Non-Metals

                                        Glass 0010 Finished Concrete 0012

                                        Clay Tile 0014 Unfinished Concrete 0014

                                        Brickwork 0015 Gravel 0029

                                        Asphalt 0016 Earth 0025

                                        Masonry 0025 Planed Wood 0012

                                        Unplaned Wood 0013

                                        Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                        Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                        Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                        Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                        The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                        cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                        simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                        The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                        References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                        a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                        Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                        French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                        Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                        7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                        Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

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                                        AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                        components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                        From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

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                                        • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                            • Circular Culvert Design Calculations Software Equations
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                                                    • Culvert Design Inlet and Outlet Control
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                                                            • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                            • Manning Equation
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                                                                                                            • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
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                                                                                                                    • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                            • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                    • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
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                                                                                                                                            • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                          Gradually Varied Flow Calculation Backwater profile

                                          Links on this page Equations Variables Manning n coefficients Error messages References

                                          Introduction In long prismatic (constant cross-sectional geometry) channels flowing water will attempt to reach the normal depth (also known as the uniform flow depth) Normal depth is the water depth determined using Mannings equation (please see our other web page for design of trapezoidal channels using Mannings equation) A gradually varied flow (GVF) profile is a plot of water depth versus distance along the channel as the water depth gradually achieves normal depth A GVF computation in a trapezoidal channel involves starting at a known depth Ys and making successive water depth computations at small distance intervals The method involves the continuity

                                          equation and energy slope equations The LMNO Engineering calculation initially computes normal depth critical depth and GVF profile type Then it computes the water depth profile and plots it The calculation also displays channel properties (depth velocity Froude number etc) at a specific location Xp entered by the user A GVF profile is also known as a water depth profile backwater

                                          calculation and non-uniform flow computation It is for steady state flows (discharge remains constant)

                                          The LMNO Engineering calculation plots GVF profiles for M1 M2 S2 S3 C1 and C3 curves M3 and S1 curves cross over the critical depth in order to achieve normal depth Flows crossing the critical depth are called rapidly varied flows and cannot be computed using GVF methods

                                          Equations and MethodologyFundamental flow equations are first presented followed by equations for computing the critical depth Yc and normal depth Yn Then

                                          using the input value of Ys the GVF profile type is determined and the GVF profile is computed using the Improved Euler method

                                          References for the equations are shown alongside the equations Mannings equation for Yn and the equation for the friction slope Sf are

                                          empirical they are shown in the form that uses meters and seconds for units Units for all other equations can be from any consistent set of units

                                          Fundamental equationsThe following equations are always valid for trapezoidal channels (Chanson 1999 Chow 1959 Simon and Korom 1997)

                                          Critical depth computationTo compute critical depth Yc the Froude number F is set to 10 Then we use the Newton method (Kahaner Moler and Nash 1989 Rao

                                          1985) along with the fundamental equations above to solve for Yc

                                          Normal depth computationTo compute normal depth Yn a cubic solution technique (Rao 1985) is used to solve the fundamental equations above in conjunction with

                                          the Manning Equation (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)

                                          Gradually varied flow profile determination (Chanson 1999 Chaudhry 1993 Chow 1959 Simon and Korom 1997)If YngtYc then the channel is considered to have a mild (M) slope If YnltYc the slope is steep (S) If Yn=Yc then the slope is termed

                                          critical (C) The slopes are further classified by a number (1 2 or 3) as follows

                                          For mild slopes (YngtYc)

                                          If YsgtYn then the slope is an M1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                          water depth gets closer to Yn as the calculation proceeds further and further upstream

                                          If YngtYs gtYc then the slope is an M2 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0

                                          fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (2 of 6)12112007 40539 PM

                                          Gradually Varied Flow Calculation Backwater profile

                                          The water depth gets closer to Yn as the calculation proceeds further and further upstream

                                          If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                                          is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                          For steep slopes (YcgtYn)

                                          If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                                          is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                          If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                          water depth gets closer to Yn as the calculation proceeds further and further downstream

                                          If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                          water depth gets closer to Yn as the calculation proceeds further and further downstream

                                          For critical slopes (Yc=Yn)

                                          If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                          water depth gets closer to Yn as the calculation proceeds further and further upstream

                                          If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                          water depth gets closer to Yn as the calculation proceeds further and further downstream

                                          There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                                          Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                                          At control section i=1 and Yi=Ys

                                          Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                                          Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                                          Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                                          P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                                          differential depth increments (this is the basis of the Improved Euler method)

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                                          Gradually Varied Flow Calculation Backwater profile

                                          Then repeat the loop by incrementing i

                                          The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                          Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                          Ap=Area at Xp [m2]

                                          A2=Area for intermediate computation in Improved Euler method [m2]

                                          dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                          (dYdX)2=Second depth increment for Improved Euler method [m]

                                          B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                          Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                          Epy=Elevation of water surface at Xp [m]

                                          F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                          g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                          P2=Second wetted perimeter computed in Improved Euler method [m]

                                          Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                          Sf1=First energy slope for Improved Euler method [dimensionless]

                                          Sf2=Second energy slope for Improved Euler method [dimensionless]

                                          T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                          T2=Second top width computed in Improved Euler method [m]

                                          Tp=Top width at Xp [m]

                                          V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                          X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                          is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                          Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                          automatically set Xp to Xmax

                                          Y=Water depth [m]Yc=Critical depth [m]

                                          Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                          Yn=Normal depth [m]

                                          Yp=Depth at Xp [m]

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                                          Gradually Varied Flow Calculation Backwater profile

                                          Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                          Y2=Second depth computed in Improved Euler method [m]

                                          Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                          Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                          Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                          Material Manning n Material Manning n

                                          Natural Streams Excavated Earth Channels

                                          Clean and Straight 0030 Clean 0022

                                          Major Rivers 0035 Gravelly 0025

                                          Sluggish with Deep Pools 0040 Weedy 0030

                                          Stony Cobbles 0035

                                          Metals Floodplains

                                          Brass 0011 Pasture Farmland 0035

                                          Cast Iron 0013 Light Brush 0050

                                          Smooth Steel 0012 Heavy Brush 0075

                                          Corrugated Metal 0022 Trees 015

                                          Non-Metals

                                          Glass 0010 Finished Concrete 0012

                                          Clay Tile 0014 Unfinished Concrete 0014

                                          Brickwork 0015 Gravel 0029

                                          Asphalt 0016 Earth 0025

                                          Masonry 0025 Planed Wood 0012

                                          Unplaned Wood 0013

                                          Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                          20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                          Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                          Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                          is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                          References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                          Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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                                          Gradually Varied Flow Calculation Backwater profile

                                          Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                          French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                          Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                          Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                          Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                          Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                          copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                          LMNOLMNOengcom httpwwwlmnoengcom

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                                          Hydraulic Jump Calculation

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                                          Hydraulic Jump in Horizontal Rectangular Channel

                                          Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                          jump length and energy loss

                                          To LMNO Engineering home page (all calculations) Related open channel calculations

                                          Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                          Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                          fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                          Hydraulic Jump Calculation

                                          Register to enable Calculate button

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          Equations

                                          Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                          V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                          L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                          where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                          Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                          What is a Hydraulic Jump

                                          A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                          According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                          oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                          occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                                          Hydraulic Jump Calculation

                                          MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                          Need F1 gt1 Upstream flow must be supercritical

                                          ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                          copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                          LMNOLMNOengcom httpwwwlmnoengcom

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                                          Manning Equation

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                                          Mannings Equation Calculator Software The open channel flow software website

                                          LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                          Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                          and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                          The product AP is also known as the hydraulic radius Rh

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                                          Non-Circular Open Channel Geometry

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                                          Geometric Calculations for Non-Circular Partially Filled Channels

                                          The open channel flow calculations software website

                                          Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                          Equations (note that R=AP)

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                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                          Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                          losses

                                          Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                          pipe Dont have to use all the pipes or nodes

                                          To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                          Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                          Register to fully enable Calculate button

                                          Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                          IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                          Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                          The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                          Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                          Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                          1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                          Pipe flows are adjusted iteratively using the following equation

                                          until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                          Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                          Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                          Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                          where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                          Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                          Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                          Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                          Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                          The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                          ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                          1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                          pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                          2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                          Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                          Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                          Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                          A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                          n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                          Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                          Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                          References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                          Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                          LMNOLMNOengcom httpwwwlmnoengcom

                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          bull

                                          Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                          Weisbach - Moody friction losses)

                                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                          (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                          Parabolic shaped pump curve is formed from the two points

                                          ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                          curve Hazen-Williams with pump curve

                                          Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                          Register to enable Calculate button

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                          IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                          A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                          For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                          (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                          Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                          calculation will look like

                                          The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                          Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                          Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                          is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                          defined for liquids

                                          Variables Units F=force L=length P=pressure T=time Back to Calculations

                                          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                          A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                          hf = Major losses for entire pipe [L] Also known as friction losses

                                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                          hm = Minor losses for entire pipe [L]

                                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                          K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                          for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                          P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                          location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                          zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                          this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                          v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                          Fitting K Fitting K

                                          Valves Elbows

                                          Globe fully open 10 Regular 90deg flanged 03

                                          Angle fully open 2 Regular 90deg threaded 15

                                          Gate fully open 015 Long radius 90deg flanged 02

                                          Gate 14 closed 026 Long radius 90deg threaded 07

                                          Gate 12 closed 21 Long radius 45deg threaded 02

                                          Gate 34 closed 17 Regular 45deg threaded 04

                                          Swing check forward flow 2

                                          Swing check backward flow infinity Tees

                                          Line flow flanged 02

                                          180deg return bends Line flow threaded 09

                                          Flanged 02 Branch flow flanged 10

                                          Threaded 15 Branch flow threaded 20

                                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          Square Connection 05 Square Connection 10

                                          Rounded Connection 02 Rounded Connection 10

                                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                          Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                          The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                          Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                          the pipe or K for the suction pipe was entered as greater than K for the entire system

                                          Other messagesK must be gt=1 If Q known Solve for D and V

                                          3=0 then K must be gt 1 in order to solve

                                          Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                          reservoirs are defined to be at zero pressure thus zero pressure difference

                                          Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                          Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                          References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                          Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                          Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                          Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                          Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                          White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                          LMNOLMNOengcom httpwwwlmnoengcom

                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          bull

                                          Circular Pressurized Water Pipes with Pump Curve

                                          (Hazen Williams)

                                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                          (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                          temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                          ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                          curve Darcy-Weisbach with pump curve

                                          Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                          Register to enable Calculate button

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                          IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                          function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                          manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                          Equations and Methodology Back to Calculations

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                          calculation will look like

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                          Variables Units L=length P=pressure T=time Back to Calculations

                                          A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                          g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                          hf = Major losses for entire pipe [L]

                                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                          hm = Minor losses for entire pipe [L]

                                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                          k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                          L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                          program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                          location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                          zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                          this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                          Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                          available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                          and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                          Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                          Material C Material C

                                          Asbestos Cement 140 Copper 130-140

                                          Brass 130-140 Galvanized iron 120

                                          Brick sewer 100 Glass 140

                                          Cast-Iron Lead 130-140

                                          New unlined 130 Plastic 140-150

                                          10 yr old 107-113 Steel

                                          20 yr old 89-100 Coal-tar enamel lined 145-150

                                          30 yr old 75-90 New unlined 140-150

                                          40 yr old 64-83 Riveted 110

                                          ConcreteConcrete-lined

                                          Steel forms 140 Tin 130

                                          Wooden forms 120 Vitrif clay (good condition) 110-140

                                          Centrifugally spun 135 Wood stave (avg condition) 120

                                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                          Fitting K Fitting K

                                          Valves Elbows

                                          Globe fully open 10 Regular 90deg flanged 03

                                          Angle fully open 2 Regular 90deg threaded 15

                                          Gate fully open 015 Long radius 90deg flanged 02

                                          Gate 14 closed 026 Long radius 90deg threaded 07

                                          Gate 12 closed 21 Long radius 45deg threaded 02

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          Gate 34 closed 17 Regular 45deg threaded 04

                                          Swing check forward flow 2

                                          Swing check backward flow infinity Tees

                                          Line flow flanged 02

                                          180deg return bends Line flow threaded 09

                                          Flanged 02 Branch flow flanged 10

                                          Threaded 15 Branch flow threaded 20

                                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                          Square Connection 05 Square Connection 10

                                          Rounded Connection 02 Rounded Connection 10

                                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                          Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                          entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                          One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                          entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                          P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                          to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                          the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                          and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                          pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                          result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                          be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                          lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                          LMNOLMNOengcom httpwwwlmnoengcom

                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                          bull

                                          Trapezoidal Open Channel Design Calculation

                                          Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                          Froude number Manning coefficient channel slope

                                          To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                          Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                          Register to enable Calculate button

                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                          Links on this page Introduction Variables Manning n coefficients Error Messages References

                                          IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                          beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                          The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                          In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                          Variables [] indicates dimensions To calculation

                                          A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                          divided by vertical distance

                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                          Oslash = Angle formed by S

                                          Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                          Material Manning n Material Manning n

                                          Natural Streams Excavated Earth Channels

                                          Clean and Straight 0030 Clean 0022

                                          Major Rivers 0035 Gravelly 0025

                                          Sluggish with Deep Pools 0040 Weedy 0030

                                          Stony Cobbles 0035

                                          Metals Floodplains

                                          Brass 0011 Pasture Farmland 0035

                                          Cast Iron 0013 Light Brush 0050

                                          Smooth Steel 0012 Heavy Brush 0075

                                          Corrugated Metal 0022 Trees 015

                                          Non-Metals

                                          Glass 0010 Finished Concrete 0012

                                          Clay Tile 0014 Unfinished Concrete 0014

                                          Brickwork 0015 Gravel 0029

                                          Asphalt 0016 Earth 0025

                                          Masonry 0025 Planed Wood 0012

                                          Unplaned Wood 0013

                                          Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                          Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                          Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                          Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                          The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                          cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                          simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                          The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                          References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                          a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                          c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                          e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                          Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                          French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                          d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                          Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                          b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                          7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                          Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                          Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                          View the version 40 New Features List

                                          Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                          AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                          fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                          components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                          From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                          View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                          Learn More About AFT Impulse 40

                                          Details Views Brochure Demo

                                          copy 2001-2007 Applied Flow Technology All Rights Reserved

                                          fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                          • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                            • Local Disk
                                              • Circular Culvert Design Calculations Software Equations
                                                  • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                    • Local Disk
                                                      • Culvert Design Inlet and Outlet Control
                                                          • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                            • Local Disk
                                                              • Design of Circular Water Pipes using Hazen Williams Equation
                                                                  • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                    • Local Disk
                                                                      • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                          • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                            • Local Disk
                                                                              • Gradually Varied Flow Calculation Backwater profile
                                                                                  • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                    • Local Disk
                                                                                      • Hydraulic Jump Calculation
                                                                                          • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                            • Local Disk
                                                                                              • Manning Equation
                                                                                                  • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                    • Local Disk
                                                                                                      • Non-Circular Open Channel Geometry
                                                                                                          • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                            • Local Disk
                                                                                                              • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                      • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                              • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                  • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                      • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                          • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                            • Local Disk
                                                                                                                                              • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                            Gradually Varied Flow Calculation Backwater profile

                                            The water depth gets closer to Yn as the calculation proceeds further and further upstream

                                            If YcgtYs then the slope is an M3 This is an unstable GVF calculation since the water depth begins below both Yn and Yc Since the slope

                                            is mild an hydraulic jump will occur Hydraulic jumps are rapidly varied flow situations that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                            For steep slopes (YcgtYn)

                                            If YsgtYc then the slope is an S1 This is an unstable GVF calculation since the water depth begins above both Yc and Yn Since the slope

                                            is steep the water depth will have to pass through the critical depth in order to reach the normal depth Passing through the critical depth is a rapidly varied flow situation that cannot be modeled by a GVF calculator Therefore the message Cannot plot S1 or M3 will be shown

                                            If YcgtYsgtYn then the slope is an S2 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                            water depth gets closer to Yn as the calculation proceeds further and further downstream

                                            If YngtYs then the slope is an S3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                            water depth gets closer to Yn as the calculation proceeds further and further downstream

                                            For critical slopes (Yc=Yn)

                                            If YsgtYc then the slope is a C1 The GVF calculation starts downstream at Xmax at a depth of Ys and proceeds upstream to X=0 The

                                            water depth gets closer to Yn as the calculation proceeds further and further upstream

                                            If YcgtYs then the slope is a C3 The GVF calculation starts upstream at X=0 at a depth of Ys and proceeds downstream to Xmax The

                                            water depth gets closer to Yn as the calculation proceeds further and further downstream

                                            There is no such thing as a C2 slope - sinceYc=Yn Ys cannot be between Yc and Yn

                                            Gradually varied flow profile (graph) computationTo compute the gradually varied flow profile (graph) the Improved Euler method (Chaudhry 1993) is used

                                            At control section i=1 and Yi=Ys

                                            Repeat for i=2 to n in increments of distance dX where dX is negative for downstream control and dX is positive for upstream controlCompute Ti Ai and Pi using the fundamental equations shown above using Y=Yi

                                            Compute the friction slope depth increment and intermediate depth (note for the friction slope equation shown the friction slope variables must be in meters and seconds)

                                            Compute T2 A2 and P2 using the fundamental equations shown above with Y=Y2 Then compute the friction slope based on T2 A2 and

                                            P2 followed by computation of a second depth increment Finally compute the water depth Yi+1 by using the average of the two

                                            differential depth increments (this is the basis of the Improved Euler method)

                                            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (3 of 6)12112007 40539 PM

                                            Gradually Varied Flow Calculation Backwater profile

                                            Then repeat the loop by incrementing i

                                            The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                            Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                            Ap=Area at Xp [m2]

                                            A2=Area for intermediate computation in Improved Euler method [m2]

                                            dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                            (dYdX)2=Second depth increment for Improved Euler method [m]

                                            B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                            Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                            Epy=Elevation of water surface at Xp [m]

                                            F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                            g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                            P2=Second wetted perimeter computed in Improved Euler method [m]

                                            Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                            Sf1=First energy slope for Improved Euler method [dimensionless]

                                            Sf2=Second energy slope for Improved Euler method [dimensionless]

                                            T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                            T2=Second top width computed in Improved Euler method [m]

                                            Tp=Top width at Xp [m]

                                            V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                            X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                            is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                            Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                            automatically set Xp to Xmax

                                            Y=Water depth [m]Yc=Critical depth [m]

                                            Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                            Yn=Normal depth [m]

                                            Yp=Depth at Xp [m]

                                            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (4 of 6)12112007 40539 PM

                                            Gradually Varied Flow Calculation Backwater profile

                                            Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                            Y2=Second depth computed in Improved Euler method [m]

                                            Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                            Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                            Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                            Material Manning n Material Manning n

                                            Natural Streams Excavated Earth Channels

                                            Clean and Straight 0030 Clean 0022

                                            Major Rivers 0035 Gravelly 0025

                                            Sluggish with Deep Pools 0040 Weedy 0030

                                            Stony Cobbles 0035

                                            Metals Floodplains

                                            Brass 0011 Pasture Farmland 0035

                                            Cast Iron 0013 Light Brush 0050

                                            Smooth Steel 0012 Heavy Brush 0075

                                            Corrugated Metal 0022 Trees 015

                                            Non-Metals

                                            Glass 0010 Finished Concrete 0012

                                            Clay Tile 0014 Unfinished Concrete 0014

                                            Brickwork 0015 Gravel 0029

                                            Asphalt 0016 Earth 0025

                                            Masonry 0025 Planed Wood 0012

                                            Unplaned Wood 0013

                                            Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                            20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                            Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                            Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                            is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                            References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                            Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                                            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                                            Gradually Varied Flow Calculation Backwater profile

                                            Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                            French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                            Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                            Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                            Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                            Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                            copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                            LMNOLMNOengcom httpwwwlmnoengcom

                                            fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                            Hydraulic Jump Calculation

                                            bull

                                            Hydraulic Jump in Horizontal Rectangular Channel

                                            Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                            jump length and energy loss

                                            To LMNO Engineering home page (all calculations) Related open channel calculations

                                            Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                            Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                            Hydraulic Jump Calculation

                                            Register to enable Calculate button

                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                            Equations

                                            Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                            V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                            L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                            where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                            Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                            What is a Hydraulic Jump

                                            A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                            According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                            oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                            occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                                            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                                            Hydraulic Jump Calculation

                                            MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                            Need F1 gt1 Upstream flow must be supercritical

                                            ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                            copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                            LMNOLMNOengcom httpwwwlmnoengcom

                                            fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                            Manning Equation

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                                            Mannings Equation Calculator Software The open channel flow software website

                                            LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                            Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                            The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                            and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                            The product AP is also known as the hydraulic radius Rh

                                            fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                            Non-Circular Open Channel Geometry

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                                            Geometric Calculations for Non-Circular Partially Filled Channels

                                            The open channel flow calculations software website

                                            Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                            You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                            Equations (note that R=AP)

                                            fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                            Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                            losses

                                            Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                            pipe Dont have to use all the pipes or nodes

                                            To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                            Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                            Register to fully enable Calculate button

                                            Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                            Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                            IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                            Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                            The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                            Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                            Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                            1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                            Pipe flows are adjusted iteratively using the following equation

                                            until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                            Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                            Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                            Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                            where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                            Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                            Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                            Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                            Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                            For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                            The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                            ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                            1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                            pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                            2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                            Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                            Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                            Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                            A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                            n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                            Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                            Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                            References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                            Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                            LMNOLMNOengcom httpwwwlmnoengcom

                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                                            Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                            Weisbach - Moody friction losses)

                                            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                            (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                            Parabolic shaped pump curve is formed from the two points

                                            ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                            curve Hazen-Williams with pump curve

                                            Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                            Register to enable Calculate button

                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                            Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                            IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                            A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                            For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                            (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                            Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                            Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                            calculation will look like

                                            The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                            Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                            Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                            is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                            defined for liquids

                                            Variables Units F=force L=length P=pressure T=time Back to Calculations

                                            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                            is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                            A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                            hf = Major losses for entire pipe [L] Also known as friction losses

                                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                            hm = Minor losses for entire pipe [L]

                                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                            K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                            for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                            P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                            location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                            zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                            V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                            this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                            v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                            Fitting K Fitting K

                                            Valves Elbows

                                            Globe fully open 10 Regular 90deg flanged 03

                                            Angle fully open 2 Regular 90deg threaded 15

                                            Gate fully open 015 Long radius 90deg flanged 02

                                            Gate 14 closed 026 Long radius 90deg threaded 07

                                            Gate 12 closed 21 Long radius 45deg threaded 02

                                            Gate 34 closed 17 Regular 45deg threaded 04

                                            Swing check forward flow 2

                                            Swing check backward flow infinity Tees

                                            Line flow flanged 02

                                            180deg return bends Line flow threaded 09

                                            Flanged 02 Branch flow flanged 10

                                            Threaded 15 Branch flow threaded 20

                                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                            Square Connection 05 Square Connection 10

                                            Rounded Connection 02 Rounded Connection 10

                                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                            Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                            The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                            Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                            the pipe or K for the suction pipe was entered as greater than K for the entire system

                                            Other messagesK must be gt=1 If Q known Solve for D and V

                                            3=0 then K must be gt 1 in order to solve

                                            Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                            reservoirs are defined to be at zero pressure thus zero pressure difference

                                            Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                            Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                            References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                            Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                            Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                            Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                            Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                            White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                            LMNOLMNOengcom httpwwwlmnoengcom

                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                            Circular Pressurized Water Pipes with Pump Curve

                                            (Hazen Williams)

                                            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                            (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                            temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                            ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                            curve Darcy-Weisbach with pump curve

                                            Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                            Register to enable Calculate button

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                                            Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                            IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                            function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                            manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                            Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                            Equations and Methodology Back to Calculations

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                            The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                            calculation will look like

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                            Variables Units L=length P=pressure T=time Back to Calculations

                                            A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                            g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                            hf = Major losses for entire pipe [L]

                                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                            hm = Minor losses for entire pipe [L]

                                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                            k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                            L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                            different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                            program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                            location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                            zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                            this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                            Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                            available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                            and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                            curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                            Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                            Material C Material C

                                            Asbestos Cement 140 Copper 130-140

                                            Brass 130-140 Galvanized iron 120

                                            Brick sewer 100 Glass 140

                                            Cast-Iron Lead 130-140

                                            New unlined 130 Plastic 140-150

                                            10 yr old 107-113 Steel

                                            20 yr old 89-100 Coal-tar enamel lined 145-150

                                            30 yr old 75-90 New unlined 140-150

                                            40 yr old 64-83 Riveted 110

                                            ConcreteConcrete-lined

                                            Steel forms 140 Tin 130

                                            Wooden forms 120 Vitrif clay (good condition) 110-140

                                            Centrifugally spun 135 Wood stave (avg condition) 120

                                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                            Fitting K Fitting K

                                            Valves Elbows

                                            Globe fully open 10 Regular 90deg flanged 03

                                            Angle fully open 2 Regular 90deg threaded 15

                                            Gate fully open 015 Long radius 90deg flanged 02

                                            Gate 14 closed 026 Long radius 90deg threaded 07

                                            Gate 12 closed 21 Long radius 45deg threaded 02

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                            Gate 34 closed 17 Regular 45deg threaded 04

                                            Swing check forward flow 2

                                            Swing check backward flow infinity Tees

                                            Line flow flanged 02

                                            180deg return bends Line flow threaded 09

                                            Flanged 02 Branch flow flanged 10

                                            Threaded 15 Branch flow threaded 20

                                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                            Square Connection 05 Square Connection 10

                                            Rounded Connection 02 Rounded Connection 10

                                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                            Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                            entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                            One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                            entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                            P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                            to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                            the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                            and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                            pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                            result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                            be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                            lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                            LMNOLMNOengcom httpwwwlmnoengcom

                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                            bull

                                            Trapezoidal Open Channel Design Calculation

                                            Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                            Froude number Manning coefficient channel slope

                                            To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                            Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                            Register to enable Calculate button

                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                            Links on this page Introduction Variables Manning n coefficients Error Messages References

                                            IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                            beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                            The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                            In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                            Variables [] indicates dimensions To calculation

                                            A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                            divided by vertical distance

                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                            Oslash = Angle formed by S

                                            Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                            Material Manning n Material Manning n

                                            Natural Streams Excavated Earth Channels

                                            Clean and Straight 0030 Clean 0022

                                            Major Rivers 0035 Gravelly 0025

                                            Sluggish with Deep Pools 0040 Weedy 0030

                                            Stony Cobbles 0035

                                            Metals Floodplains

                                            Brass 0011 Pasture Farmland 0035

                                            Cast Iron 0013 Light Brush 0050

                                            Smooth Steel 0012 Heavy Brush 0075

                                            Corrugated Metal 0022 Trees 015

                                            Non-Metals

                                            Glass 0010 Finished Concrete 0012

                                            Clay Tile 0014 Unfinished Concrete 0014

                                            Brickwork 0015 Gravel 0029

                                            Asphalt 0016 Earth 0025

                                            Masonry 0025 Planed Wood 0012

                                            Unplaned Wood 0013

                                            Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                            Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                            Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                            Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                            The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                            cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                            simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                            The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                            References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                            a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                            c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                            e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                            Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                            French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                            d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                            Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                            b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                            7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                            Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                            Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                            View the version 40 New Features List

                                            Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                            AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                            components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                            From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                            View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                            Learn More About AFT Impulse 40

                                            Details Views Brochure Demo

                                            copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                            • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                              • Local Disk
                                                • Circular Culvert Design Calculations Software Equations
                                                    • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                      • Local Disk
                                                        • Culvert Design Inlet and Outlet Control
                                                            • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                              • Local Disk
                                                                • Design of Circular Water Pipes using Hazen Williams Equation
                                                                    • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                      • Local Disk
                                                                        • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                            • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                              • Local Disk
                                                                                • Gradually Varied Flow Calculation Backwater profile
                                                                                    • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                      • Local Disk
                                                                                        • Hydraulic Jump Calculation
                                                                                            • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                              • Local Disk
                                                                                                • Manning Equation
                                                                                                    • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                      • Local Disk
                                                                                                        • Non-Circular Open Channel Geometry
                                                                                                            • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                              • Local Disk
                                                                                                                • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                      • Local Disk
                                                                                                                        • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                              • Local Disk
                                                                                                                                • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                    • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                      • Local Disk
                                                                                                                                        • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                            • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                              • Local Disk
                                                                                                                                                • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                              Gradually Varied Flow Calculation Backwater profile

                                              Then repeat the loop by incrementing i

                                              The LMNO Engineering calculation uses an unequal node spacing so that more nodes are used at the beginning of the calculation to improve accuracy The first node spacing is approximately 10-10 m and there are 4500 distance increments The results have been checked against hand calculations spreadsheets and results shown in Chaudhry (1993) Chow (1959) French (1985) Henderson (1966) and Simon and Korom (1997)

                                              Variables Back to calculationVariables are shown below in SI units (metric) If you work through the above equations by hand use the SI units shown - since many of the equations are empirical and are valid only with the indicated units (The calculation performs internal unit conversions which allow you to select a variety of different units)A=Channel cross-sectional area [m2]Ai=Area computed at successive i intervals in Improved Euler method [m2]

                                              Ap=Area at Xp [m2]

                                              A2=Area for intermediate computation in Improved Euler method [m2]

                                              dX=Distance increment for Improved Euler method [m] Negative for M1 M2 and C1 since computation proceeds upstream Positive for S2 S3 and C3 since computation proceeds downstream(dYdX)1=First depth increment for Improved Euler method [m]

                                              (dYdX)2=Second depth increment for Improved Euler method [m]

                                              B=Channel bottom width [m]E=Elevation [m] The calculation automatically sets the channel invert elevation to 00 at Xmax

                                              Epi=Elevation of channel invert at Xp [m] Invert means bottom of the channel

                                              Epy=Elevation of water surface at Xp [m]

                                              F=Froude number [dimensionless]Fp=Froude number at Xp [dimensionless]

                                              g=Acceleration due to gravity 98066 ms2i=Loop index for computing GVF profilen=Mannings n value [dimensionless] See table below for valuesP=Channel wetted perimeter [m]Pi=Wetted perimeter computed at successive i intervals in Improved Euler method [m]

                                              P2=Second wetted perimeter computed in Improved Euler method [m]

                                              Q=Discharge (flowrate) of water in the channel [m3s]So=Slope of bottom of channel (vertical to horizontal ratio) [mm]

                                              Sf1=First energy slope for Improved Euler method [dimensionless]

                                              Sf2=Second energy slope for Improved Euler method [dimensionless]

                                              T=Top width of water in channel [m]Ti=Top width computed at successive i intervals in Improved Euler method [m]

                                              T2=Second top width computed in Improved Euler method [m]

                                              Tp=Top width at Xp [m]

                                              V=Average velocity of water [ms]Vp=Velocity at Xp [ms]

                                              X=Distance along channel [m]Xmax=Maximum distance for computing GVF profile [m] Profile is always plotted from X=0 to Xmax For M1 M2 and C1 profiles Ys

                                              is at X=Xmax For S2 S3 and C3 profiles Ys is at X=0

                                              Xp=Distance entered by user for showing channel properties [m] Cannot exceed Xmax If user enters XpgtXmax the calculation will

                                              automatically set Xp to Xmax

                                              Y=Water depth [m]Yc=Critical depth [m]

                                              Yi=Water depth computed at successive i intervals in Improved Euler method [m]

                                              Yn=Normal depth [m]

                                              Yp=Depth at Xp [m]

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                                              Gradually Varied Flow Calculation Backwater profile

                                              Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                              Y2=Second depth computed in Improved Euler method [m]

                                              Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                              Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                              Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                              Material Manning n Material Manning n

                                              Natural Streams Excavated Earth Channels

                                              Clean and Straight 0030 Clean 0022

                                              Major Rivers 0035 Gravelly 0025

                                              Sluggish with Deep Pools 0040 Weedy 0030

                                              Stony Cobbles 0035

                                              Metals Floodplains

                                              Brass 0011 Pasture Farmland 0035

                                              Cast Iron 0013 Light Brush 0050

                                              Smooth Steel 0012 Heavy Brush 0075

                                              Corrugated Metal 0022 Trees 015

                                              Non-Metals

                                              Glass 0010 Finished Concrete 0012

                                              Clay Tile 0014 Unfinished Concrete 0014

                                              Brickwork 0015 Gravel 0029

                                              Asphalt 0016 Earth 0025

                                              Masonry 0025 Planed Wood 0012

                                              Unplaned Wood 0013

                                              Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                              20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                              Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                              Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                              is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                              References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                              Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

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                                              Gradually Varied Flow Calculation Backwater profile

                                              Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                              French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                              Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                              Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                              Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                              Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                              copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                              LMNOLMNOengcom httpwwwlmnoengcom

                                              fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                              Hydraulic Jump Calculation

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                                              Hydraulic Jump in Horizontal Rectangular Channel

                                              Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                              jump length and energy loss

                                              To LMNO Engineering home page (all calculations) Related open channel calculations

                                              Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                              Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                              fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                              Hydraulic Jump Calculation

                                              Register to enable Calculate button

                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                              Equations

                                              Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                              V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                              L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                              where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                              Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                              What is a Hydraulic Jump

                                              A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                              According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                              oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                              occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                                              Hydraulic Jump Calculation

                                              MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                              Need F1 gt1 Upstream flow must be supercritical

                                              ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                              copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                              LMNOLMNOengcom httpwwwlmnoengcom

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                                              Manning Equation

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                                              Mannings Equation Calculator Software The open channel flow software website

                                              LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                              Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                              The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                              and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                              The product AP is also known as the hydraulic radius Rh

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                                              Non-Circular Open Channel Geometry

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                                              Geometric Calculations for Non-Circular Partially Filled Channels

                                              The open channel flow calculations software website

                                              Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                              You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                              Equations (note that R=AP)

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                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                              Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                              losses

                                              Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                              pipe Dont have to use all the pipes or nodes

                                              To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                              Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                              Register to fully enable Calculate button

                                              Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                              Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                              IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                              Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                              The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                              Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                              Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                              1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                              Pipe flows are adjusted iteratively using the following equation

                                              until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                              Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                              Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                              Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

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                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                              where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                              Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                              Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                              Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                              Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                              For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                              The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                              ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                              1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                              pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                              2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                              Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                              Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                              Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                              A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                              n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                              Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                              Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                              References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                              Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                              LMNOLMNOengcom httpwwwlmnoengcom

                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                                              Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                              Weisbach - Moody friction losses)

                                              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                              (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                              Parabolic shaped pump curve is formed from the two points

                                              ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                              curve Hazen-Williams with pump curve

                                              Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                              Register to enable Calculate button

                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                              Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                              IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                              A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                              For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                              (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                              Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                              Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                              calculation will look like

                                              The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                              Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                              Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                              is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                              defined for liquids

                                              Variables Units F=force L=length P=pressure T=time Back to Calculations

                                              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                              is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                              A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                              hf = Major losses for entire pipe [L] Also known as friction losses

                                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                              hm = Minor losses for entire pipe [L]

                                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                              K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                              for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                              P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                              location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                              zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                              V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                              this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                              v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                              Fitting K Fitting K

                                              Valves Elbows

                                              Globe fully open 10 Regular 90deg flanged 03

                                              Angle fully open 2 Regular 90deg threaded 15

                                              Gate fully open 015 Long radius 90deg flanged 02

                                              Gate 14 closed 026 Long radius 90deg threaded 07

                                              Gate 12 closed 21 Long radius 45deg threaded 02

                                              Gate 34 closed 17 Regular 45deg threaded 04

                                              Swing check forward flow 2

                                              Swing check backward flow infinity Tees

                                              Line flow flanged 02

                                              180deg return bends Line flow threaded 09

                                              Flanged 02 Branch flow flanged 10

                                              Threaded 15 Branch flow threaded 20

                                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                              Square Connection 05 Square Connection 10

                                              Rounded Connection 02 Rounded Connection 10

                                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                              Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                              The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                              Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                              the pipe or K for the suction pipe was entered as greater than K for the entire system

                                              Other messagesK must be gt=1 If Q known Solve for D and V

                                              3=0 then K must be gt 1 in order to solve

                                              Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                              reservoirs are defined to be at zero pressure thus zero pressure difference

                                              Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                              Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                              References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                              Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                              Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                              Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                              Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                              White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                              LMNOLMNOengcom httpwwwlmnoengcom

                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                              Circular Pressurized Water Pipes with Pump Curve

                                              (Hazen Williams)

                                              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                              (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                              temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                              ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                              curve Darcy-Weisbach with pump curve

                                              Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

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                                              Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                              IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                              function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                              manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                              Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                              Equations and Methodology Back to Calculations

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                              The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                              calculation will look like

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                              All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                              Variables Units L=length P=pressure T=time Back to Calculations

                                              A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                              g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                              hf = Major losses for entire pipe [L]

                                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                              hm = Minor losses for entire pipe [L]

                                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                              k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                              L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                              different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                              program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                              location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                              zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                              this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                              Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                              available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                              and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                              curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                              Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                              Material C Material C

                                              Asbestos Cement 140 Copper 130-140

                                              Brass 130-140 Galvanized iron 120

                                              Brick sewer 100 Glass 140

                                              Cast-Iron Lead 130-140

                                              New unlined 130 Plastic 140-150

                                              10 yr old 107-113 Steel

                                              20 yr old 89-100 Coal-tar enamel lined 145-150

                                              30 yr old 75-90 New unlined 140-150

                                              40 yr old 64-83 Riveted 110

                                              ConcreteConcrete-lined

                                              Steel forms 140 Tin 130

                                              Wooden forms 120 Vitrif clay (good condition) 110-140

                                              Centrifugally spun 135 Wood stave (avg condition) 120

                                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                              Fitting K Fitting K

                                              Valves Elbows

                                              Globe fully open 10 Regular 90deg flanged 03

                                              Angle fully open 2 Regular 90deg threaded 15

                                              Gate fully open 015 Long radius 90deg flanged 02

                                              Gate 14 closed 026 Long radius 90deg threaded 07

                                              Gate 12 closed 21 Long radius 45deg threaded 02

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                              Gate 34 closed 17 Regular 45deg threaded 04

                                              Swing check forward flow 2

                                              Swing check backward flow infinity Tees

                                              Line flow flanged 02

                                              180deg return bends Line flow threaded 09

                                              Flanged 02 Branch flow flanged 10

                                              Threaded 15 Branch flow threaded 20

                                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                              Square Connection 05 Square Connection 10

                                              Rounded Connection 02 Rounded Connection 10

                                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                              Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                              entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                              One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                              entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                              P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                              to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                              the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                              and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                              pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                              result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                              be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                              lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                              LMNOLMNOengcom httpwwwlmnoengcom

                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                              Trapezoidal Open Channel Design Calculation

                                              Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                              Froude number Manning coefficient channel slope

                                              To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                              Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                              Register to enable Calculate button

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                                              Links on this page Introduction Variables Manning n coefficients Error Messages References

                                              IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                              beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                              The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                              In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                              Variables [] indicates dimensions To calculation

                                              A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                              divided by vertical distance

                                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                              Oslash = Angle formed by S

                                              Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                              Material Manning n Material Manning n

                                              Natural Streams Excavated Earth Channels

                                              Clean and Straight 0030 Clean 0022

                                              Major Rivers 0035 Gravelly 0025

                                              Sluggish with Deep Pools 0040 Weedy 0030

                                              Stony Cobbles 0035

                                              Metals Floodplains

                                              Brass 0011 Pasture Farmland 0035

                                              Cast Iron 0013 Light Brush 0050

                                              Smooth Steel 0012 Heavy Brush 0075

                                              Corrugated Metal 0022 Trees 015

                                              Non-Metals

                                              Glass 0010 Finished Concrete 0012

                                              Clay Tile 0014 Unfinished Concrete 0014

                                              Brickwork 0015 Gravel 0029

                                              Asphalt 0016 Earth 0025

                                              Masonry 0025 Planed Wood 0012

                                              Unplaned Wood 0013

                                              Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                              Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                              Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                              Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                              The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                              cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                              simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                              The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                              References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                              a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                              c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                              e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                              Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                              French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                              d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                              Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                              b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                              7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                              Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                              Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                              View the version 40 New Features List

                                              Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                              AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                              components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                              From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                              View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                              Learn More About AFT Impulse 40

                                              Details Views Brochure Demo

                                              copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                              • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                • Local Disk
                                                  • Circular Culvert Design Calculations Software Equations
                                                      • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                                          • Culvert Design Inlet and Outlet Control
                                                              • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                  • Design of Circular Water Pipes using Hazen Williams Equation
                                                                      • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                          • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                              • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                  • Gradually Varied Flow Calculation Backwater profile
                                                                                      • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                          • Hydraulic Jump Calculation
                                                                                              • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                  • Manning Equation
                                                                                                      • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                          • Non-Circular Open Channel Geometry
                                                                                                              • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                  • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                          • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                  • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                      • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                          • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                              • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                • Local Disk
                                                                                                                                                  • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                Gradually Varied Flow Calculation Backwater profile

                                                Ys=Starting depth [m] This is also known as the depth at the control section It is the depth that GVF calculations start at

                                                Y2=Second depth computed in Improved Euler method [m]

                                                Z1=One channel side slope (horizontal to vertical ratio) [mm]

                                                Z2=The other channel side slope (horizontal to vertical ratio) [mm]

                                                Manning n Coefficients Back to calculationThe Mannings n coefficients were compiled from Chaudhry (1993) Chow (1959) French (1985) and Mays (1999)

                                                Material Manning n Material Manning n

                                                Natural Streams Excavated Earth Channels

                                                Clean and Straight 0030 Clean 0022

                                                Major Rivers 0035 Gravelly 0025

                                                Sluggish with Deep Pools 0040 Weedy 0030

                                                Stony Cobbles 0035

                                                Metals Floodplains

                                                Brass 0011 Pasture Farmland 0035

                                                Cast Iron 0013 Light Brush 0050

                                                Smooth Steel 0012 Heavy Brush 0075

                                                Corrugated Metal 0022 Trees 015

                                                Non-Metals

                                                Glass 0010 Finished Concrete 0012

                                                Clay Tile 0014 Unfinished Concrete 0014

                                                Brickwork 0015 Gravel 0029

                                                Asphalt 0016 Earth 0025

                                                Masonry 0025 Planed Wood 0012

                                                Unplaned Wood 0013

                                                Error Messages Back to calculationInitial input checks The following messages are generated from improper input valuesNeed 1e-20ltQlt1e50 m3s Need 1e-20ltBlt1e6 m Need Z1 Z2 gt=0 Z1 Z2 cannot both be 0 Need 1e-9ltnlt20 Need 1e-

                                                20ltSolt1e99 Need 0001ltXmaxlt1e6 m Need 1e-20ltYslt100 m Need Xpgt=0

                                                Run-time messages The following messages may be generated during executionInfeasible input Inputs are unusually large or small causing the program to have trouble computing Yn or Yc

                                                Cannot plot S1 or M3 As discussed above these two GVF profiles encounter rapidly varied flow where the water depth crosses through critical depthNo graph Ys=Yn This is a uniform flow situation not a GVF calculation Water depth will remain at normal depth so the GVF profile

                                                is not computedYn at x=874231 m This is the distance where the water depth is within 001 of the normal depth

                                                References Back to calculationChanson H 1999 The Hydraulics of Open Channel Flow John Wiley and Sons Inc

                                                Chaudhry M H 1993 Open-Channel Flow Prentice-Hall Inc

                                                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (5 of 6)12112007 40539 PM

                                                Gradually Varied Flow Calculation Backwater profile

                                                Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                                Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                                Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                                Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                                copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                                Hydraulic Jump Calculation

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                                                Hydraulic Jump in Horizontal Rectangular Channel

                                                Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                                jump length and energy loss

                                                To LMNO Engineering home page (all calculations) Related open channel calculations

                                                Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                                fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                                Hydraulic Jump Calculation

                                                Register to enable Calculate button

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                Equations

                                                Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                                V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                                L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                                where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                                Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                                What is a Hydraulic Jump

                                                A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                                According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                                oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                                occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                                                fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                                                Hydraulic Jump Calculation

                                                MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                                Need F1 gt1 Upstream flow must be supercritical

                                                ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                                copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                                Manning Equation

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                                                Mannings Equation Calculator Software The open channel flow software website

                                                LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                                Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                                and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                                The product AP is also known as the hydraulic radius Rh

                                                fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                                Non-Circular Open Channel Geometry

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                                                Geometric Calculations for Non-Circular Partially Filled Channels

                                                The open channel flow calculations software website

                                                Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                                Equations (note that R=AP)

                                                fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                bull

                                                Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                losses

                                                Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                pipe Dont have to use all the pipes or nodes

                                                To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                Register to fully enable Calculate button

                                                Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                Pipe flows are adjusted iteratively using the following equation

                                                until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                bull

                                                Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                Weisbach - Moody friction losses)

                                                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                Parabolic shaped pump curve is formed from the two points

                                                ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                curve Hazen-Williams with pump curve

                                                Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                Register to enable Calculate button

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                calculation will look like

                                                The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                defined for liquids

                                                Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                hf = Major losses for entire pipe [L] Also known as friction losses

                                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                hm = Minor losses for entire pipe [L]

                                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                Fitting K Fitting K

                                                Valves Elbows

                                                Globe fully open 10 Regular 90deg flanged 03

                                                Angle fully open 2 Regular 90deg threaded 15

                                                Gate fully open 015 Long radius 90deg flanged 02

                                                Gate 14 closed 026 Long radius 90deg threaded 07

                                                Gate 12 closed 21 Long radius 45deg threaded 02

                                                Gate 34 closed 17 Regular 45deg threaded 04

                                                Swing check forward flow 2

                                                Swing check backward flow infinity Tees

                                                Line flow flanged 02

                                                180deg return bends Line flow threaded 09

                                                Flanged 02 Branch flow flanged 10

                                                Threaded 15 Branch flow threaded 20

                                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                Square Connection 05 Square Connection 10

                                                Rounded Connection 02 Rounded Connection 10

                                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                Other messagesK must be gt=1 If Q known Solve for D and V

                                                3=0 then K must be gt 1 in order to solve

                                                Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                reservoirs are defined to be at zero pressure thus zero pressure difference

                                                Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                bull

                                                Circular Pressurized Water Pipes with Pump Curve

                                                (Hazen Williams)

                                                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                curve Darcy-Weisbach with pump curve

                                                Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                Register to enable Calculate button

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                Equations and Methodology Back to Calculations

                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                calculation will look like

                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                Variables Units L=length P=pressure T=time Back to Calculations

                                                A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                hf = Major losses for entire pipe [L]

                                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                hm = Minor losses for entire pipe [L]

                                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                Material C Material C

                                                Asbestos Cement 140 Copper 130-140

                                                Brass 130-140 Galvanized iron 120

                                                Brick sewer 100 Glass 140

                                                Cast-Iron Lead 130-140

                                                New unlined 130 Plastic 140-150

                                                10 yr old 107-113 Steel

                                                20 yr old 89-100 Coal-tar enamel lined 145-150

                                                30 yr old 75-90 New unlined 140-150

                                                40 yr old 64-83 Riveted 110

                                                ConcreteConcrete-lined

                                                Steel forms 140 Tin 130

                                                Wooden forms 120 Vitrif clay (good condition) 110-140

                                                Centrifugally spun 135 Wood stave (avg condition) 120

                                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                Fitting K Fitting K

                                                Valves Elbows

                                                Globe fully open 10 Regular 90deg flanged 03

                                                Angle fully open 2 Regular 90deg threaded 15

                                                Gate fully open 015 Long radius 90deg flanged 02

                                                Gate 14 closed 026 Long radius 90deg threaded 07

                                                Gate 12 closed 21 Long radius 45deg threaded 02

                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                Gate 34 closed 17 Regular 45deg threaded 04

                                                Swing check forward flow 2

                                                Swing check backward flow infinity Tees

                                                Line flow flanged 02

                                                180deg return bends Line flow threaded 09

                                                Flanged 02 Branch flow flanged 10

                                                Threaded 15 Branch flow threaded 20

                                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                Square Connection 05 Square Connection 10

                                                Rounded Connection 02 Rounded Connection 10

                                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                Trapezoidal Open Channel Design Calculation

                                                Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                Froude number Manning coefficient channel slope

                                                To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                Register to enable Calculate button

                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                Variables [] indicates dimensions To calculation

                                                A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                divided by vertical distance

                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                Oslash = Angle formed by S

                                                Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                Material Manning n Material Manning n

                                                Natural Streams Excavated Earth Channels

                                                Clean and Straight 0030 Clean 0022

                                                Major Rivers 0035 Gravelly 0025

                                                Sluggish with Deep Pools 0040 Weedy 0030

                                                Stony Cobbles 0035

                                                Metals Floodplains

                                                Brass 0011 Pasture Farmland 0035

                                                Cast Iron 0013 Light Brush 0050

                                                Smooth Steel 0012 Heavy Brush 0075

                                                Corrugated Metal 0022 Trees 015

                                                Non-Metals

                                                Glass 0010 Finished Concrete 0012

                                                Clay Tile 0014 Unfinished Concrete 0014

                                                Brickwork 0015 Gravel 0029

                                                Asphalt 0016 Earth 0025

                                                Masonry 0025 Planed Wood 0012

                                                Unplaned Wood 0013

                                                Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                View the version 40 New Features List

                                                Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                Learn More About AFT Impulse 40

                                                Details Views Brochure Demo

                                                copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                  • Local Disk
                                                    • Circular Culvert Design Calculations Software Equations
                                                        • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                          • Local Disk
                                                            • Culvert Design Inlet and Outlet Control
                                                                • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                  • Local Disk
                                                                    • Design of Circular Water Pipes using Hazen Williams Equation
                                                                        • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                          • Local Disk
                                                                            • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                  • Local Disk
                                                                                    • Gradually Varied Flow Calculation Backwater profile
                                                                                        • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                          • Local Disk
                                                                                            • Hydraulic Jump Calculation
                                                                                                • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                  • Local Disk
                                                                                                    • Manning Equation
                                                                                                        • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                          • Local Disk
                                                                                                            • Non-Circular Open Channel Geometry
                                                                                                                • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                  • Local Disk
                                                                                                                    • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                        • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                          • Local Disk
                                                                                                                            • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                  • Local Disk
                                                                                                                                    • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                        • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                          • Local Disk
                                                                                                                                            • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                  • Local Disk
                                                                                                                                                    • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                  Gradually Varied Flow Calculation Backwater profile

                                                  Chow V T 1959 Open-Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                  French R H 1985 Open-Channel Hydraulics McGraw-Hill Book Co

                                                  Henderson F M 1966 Open Channel Flow MacMillan Publishing Co

                                                  Kahaner D C Moler and S Nash 1989 Numerical Methods and Software Prentice-Hall Inc 2ed

                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                  Rao S 1985 Optimization Theory and Applications Wiley Eastern Limited 2ed

                                                  Simon A and S Korom 1997 Hydraulics Prentice-Hall Inc 4ed

                                                  copy 2002 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio 45701 USA (740) 592-1890

                                                  LMNOLMNOengcom httpwwwlmnoengcom

                                                  fileE|engineeringhydraulicsGradually20Varied20Flow20Calculation_20Backwater20profilehtm (6 of 6)12112007 40539 PM

                                                  Hydraulic Jump Calculation

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                                                  Hydraulic Jump in Horizontal Rectangular Channel

                                                  Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                                  jump length and energy loss

                                                  To LMNO Engineering home page (all calculations) Related open channel calculations

                                                  Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                  Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

                                                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (1 of 3)12112007 40633 PM

                                                  Hydraulic Jump Calculation

                                                  Register to enable Calculate button

                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                  Equations

                                                  Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                                  V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                                  L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                                  where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                                  Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                                  What is a Hydraulic Jump

                                                  A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                                  According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                                  oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                                  occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

                                                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (2 of 3)12112007 40633 PM

                                                  Hydraulic Jump Calculation

                                                  MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                                  Need F1 gt1 Upstream flow must be supercritical

                                                  ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                                  copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                  LMNOLMNOengcom httpwwwlmnoengcom

                                                  fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                                  Manning Equation

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                                                  Mannings Equation Calculator Software The open channel flow software website

                                                  LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                                  Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                  The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                                  and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                                  The product AP is also known as the hydraulic radius Rh

                                                  fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                                  Non-Circular Open Channel Geometry

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                                                  Geometric Calculations for Non-Circular Partially Filled Channels

                                                  The open channel flow calculations software website

                                                  Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                  You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                                  Equations (note that R=AP)

                                                  fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                                  Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                  losses

                                                  Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                  pipe Dont have to use all the pipes or nodes

                                                  To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                  Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                  Register to fully enable Calculate button

                                                  Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                  Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                  IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                  Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                  The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                  Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                  Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                  1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                  Pipe flows are adjusted iteratively using the following equation

                                                  until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                  Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                  Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                  Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

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                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                  where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                  Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                  Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                  Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                  Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                  For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                  The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                  ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                  1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                  pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                  2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                  Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                  Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                  Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                  A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                  n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                  Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                  Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                  References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                  Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  bull

                                                  Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                  Weisbach - Moody friction losses)

                                                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                  (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                  Parabolic shaped pump curve is formed from the two points

                                                  ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                  curve Hazen-Williams with pump curve

                                                  Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                  Register to enable Calculate button

                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                  Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                  IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                  A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                  For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                  (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                  Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                  calculation will look like

                                                  The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                  Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                  Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                  is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                  defined for liquids

                                                  Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                  A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                  hf = Major losses for entire pipe [L] Also known as friction losses

                                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                  hm = Minor losses for entire pipe [L]

                                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                  K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                  for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                  P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                  location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                  zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                  this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                  v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                  Fitting K Fitting K

                                                  Valves Elbows

                                                  Globe fully open 10 Regular 90deg flanged 03

                                                  Angle fully open 2 Regular 90deg threaded 15

                                                  Gate fully open 015 Long radius 90deg flanged 02

                                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                                  Gate 12 closed 21 Long radius 45deg threaded 02

                                                  Gate 34 closed 17 Regular 45deg threaded 04

                                                  Swing check forward flow 2

                                                  Swing check backward flow infinity Tees

                                                  Line flow flanged 02

                                                  180deg return bends Line flow threaded 09

                                                  Flanged 02 Branch flow flanged 10

                                                  Threaded 15 Branch flow threaded 20

                                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  Square Connection 05 Square Connection 10

                                                  Rounded Connection 02 Rounded Connection 10

                                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                  Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                  The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                  Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                  the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                  Other messagesK must be gt=1 If Q known Solve for D and V

                                                  3=0 then K must be gt 1 in order to solve

                                                  Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                  reservoirs are defined to be at zero pressure thus zero pressure difference

                                                  Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                  Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                  References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                  Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                  Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                  Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                  Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                  White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  bull

                                                  Circular Pressurized Water Pipes with Pump Curve

                                                  (Hazen Williams)

                                                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                  (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                  temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                  ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                  curve Darcy-Weisbach with pump curve

                                                  Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                  Register to enable Calculate button

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                                                  Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                  IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                  function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                  manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                  Equations and Methodology Back to Calculations

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                  calculation will look like

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                  Variables Units L=length P=pressure T=time Back to Calculations

                                                  A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                  g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                  hf = Major losses for entire pipe [L]

                                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                  hm = Minor losses for entire pipe [L]

                                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                  k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                  L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                  program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                  location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                  zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                  this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                  Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                  available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                  and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                  Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                  Material C Material C

                                                  Asbestos Cement 140 Copper 130-140

                                                  Brass 130-140 Galvanized iron 120

                                                  Brick sewer 100 Glass 140

                                                  Cast-Iron Lead 130-140

                                                  New unlined 130 Plastic 140-150

                                                  10 yr old 107-113 Steel

                                                  20 yr old 89-100 Coal-tar enamel lined 145-150

                                                  30 yr old 75-90 New unlined 140-150

                                                  40 yr old 64-83 Riveted 110

                                                  ConcreteConcrete-lined

                                                  Steel forms 140 Tin 130

                                                  Wooden forms 120 Vitrif clay (good condition) 110-140

                                                  Centrifugally spun 135 Wood stave (avg condition) 120

                                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                  Fitting K Fitting K

                                                  Valves Elbows

                                                  Globe fully open 10 Regular 90deg flanged 03

                                                  Angle fully open 2 Regular 90deg threaded 15

                                                  Gate fully open 015 Long radius 90deg flanged 02

                                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                                  Gate 12 closed 21 Long radius 45deg threaded 02

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  Gate 34 closed 17 Regular 45deg threaded 04

                                                  Swing check forward flow 2

                                                  Swing check backward flow infinity Tees

                                                  Line flow flanged 02

                                                  180deg return bends Line flow threaded 09

                                                  Flanged 02 Branch flow flanged 10

                                                  Threaded 15 Branch flow threaded 20

                                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                  Square Connection 05 Square Connection 10

                                                  Rounded Connection 02 Rounded Connection 10

                                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                  Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                  entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                  One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                  entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                  P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                  to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                  the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                  and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                  pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                  result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                  be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                  lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                  Trapezoidal Open Channel Design Calculation

                                                  Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                  Froude number Manning coefficient channel slope

                                                  To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                  Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                                  Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                  IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                  beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                  The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                  In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                  Variables [] indicates dimensions To calculation

                                                  A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                  divided by vertical distance

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                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                  Oslash = Angle formed by S

                                                  Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                  Material Manning n Material Manning n

                                                  Natural Streams Excavated Earth Channels

                                                  Clean and Straight 0030 Clean 0022

                                                  Major Rivers 0035 Gravelly 0025

                                                  Sluggish with Deep Pools 0040 Weedy 0030

                                                  Stony Cobbles 0035

                                                  Metals Floodplains

                                                  Brass 0011 Pasture Farmland 0035

                                                  Cast Iron 0013 Light Brush 0050

                                                  Smooth Steel 0012 Heavy Brush 0075

                                                  Corrugated Metal 0022 Trees 015

                                                  Non-Metals

                                                  Glass 0010 Finished Concrete 0012

                                                  Clay Tile 0014 Unfinished Concrete 0014

                                                  Brickwork 0015 Gravel 0029

                                                  Asphalt 0016 Earth 0025

                                                  Masonry 0025 Planed Wood 0012

                                                  Unplaned Wood 0013

                                                  Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                  Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                  Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                  Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                  The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                  cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                  simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                  The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                  References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                  a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                  c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                  e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                  Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                  French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                  d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                  Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                  b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                  7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                  Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                  View the version 40 New Features List

                                                  Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                  AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                  components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                  From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                  View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                  Learn More About AFT Impulse 40

                                                  Details Views Brochure Demo

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                                                  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                    • Local Disk
                                                      • Circular Culvert Design Calculations Software Equations
                                                          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                                              • Culvert Design Inlet and Outlet Control
                                                                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                      • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                              • DPlot Graphing Software for Scientists and Engineers - Home Page
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                                                                                      • Gradually Varied Flow Calculation Backwater profile
                                                                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                              • Hydraulic Jump Calculation
                                                                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                      • Manning Equation
                                                                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                              • Non-Circular Open Channel Geometry
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                                                                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                    Hydraulic Jump Calculation

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                                                    Hydraulic Jump in Horizontal Rectangular Channel

                                                    Hydraulic jump for water in rectangular horizontal channel Enter discharge channel width upstream depth Compute downstream depth Froude numbers depth ratio velocities

                                                    jump length and energy loss

                                                    To LMNO Engineering home page (all calculations) Related open channel calculations

                                                    Rectangular Channel Design Trapezoidal Channel DesignGradually varied flow in trapezoidal channel Unit Conversions

                                                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                    Photograph from Ohio Universitys Fluid Mechanics Laboratory Athens Ohio USA

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                                                    Hydraulic Jump Calculation

                                                    Register to enable Calculate button

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                                                    Equations

                                                    Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                                    V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                                    L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                                    where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                                    Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                                    What is a Hydraulic Jump

                                                    A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                                    According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                                    oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                                    occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                                                    Hydraulic Jump Calculation

                                                    MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                                    Need F1 gt1 Upstream flow must be supercritical

                                                    ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                                    copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                    LMNOLMNOengcom httpwwwlmnoengcom

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                                                    Manning Equation

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                                                    Mannings Equation Calculator Software The open channel flow software website

                                                    LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                                    Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                    The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                                    and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                                    The product AP is also known as the hydraulic radius Rh

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                                                    Non-Circular Open Channel Geometry

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                                                    Geometric Calculations for Non-Circular Partially Filled Channels

                                                    The open channel flow calculations software website

                                                    Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                    You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                                    Equations (note that R=AP)

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                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                                    Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                    losses

                                                    Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                    pipe Dont have to use all the pipes or nodes

                                                    To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                    Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                    Register to fully enable Calculate button

                                                    Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                    Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                    IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                    Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                    The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                    Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                    Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                    1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                    Pipe flows are adjusted iteratively using the following equation

                                                    until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                    Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                    Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                    Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                    where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                    Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                    Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                    Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                    Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                    For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                    The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                    ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                    1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                    pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                    2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                    Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                    Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                    Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                    A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                    n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                    Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                    Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                    References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                    Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                    LMNOLMNOengcom httpwwwlmnoengcom

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                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                                                    Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                    Weisbach - Moody friction losses)

                                                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                    (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                    Parabolic shaped pump curve is formed from the two points

                                                    ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                    curve Hazen-Williams with pump curve

                                                    Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                    Register to enable Calculate button

                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                    Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                    IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                    A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                    For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                    (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                    Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                    Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                    calculation will look like

                                                    The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                    Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                    Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                    is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                    defined for liquids

                                                    Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                    is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                    A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                    hf = Major losses for entire pipe [L] Also known as friction losses

                                                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                    hm = Minor losses for entire pipe [L]

                                                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                    K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                    for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                    P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                    location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                    zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                    V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                    this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                    v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                    Fitting K Fitting K

                                                    Valves Elbows

                                                    Globe fully open 10 Regular 90deg flanged 03

                                                    Angle fully open 2 Regular 90deg threaded 15

                                                    Gate fully open 015 Long radius 90deg flanged 02

                                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                                    Gate 34 closed 17 Regular 45deg threaded 04

                                                    Swing check forward flow 2

                                                    Swing check backward flow infinity Tees

                                                    Line flow flanged 02

                                                    180deg return bends Line flow threaded 09

                                                    Flanged 02 Branch flow flanged 10

                                                    Threaded 15 Branch flow threaded 20

                                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                    Square Connection 05 Square Connection 10

                                                    Rounded Connection 02 Rounded Connection 10

                                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                    Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                    The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                    Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                    the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                    Other messagesK must be gt=1 If Q known Solve for D and V

                                                    3=0 then K must be gt 1 in order to solve

                                                    Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                    reservoirs are defined to be at zero pressure thus zero pressure difference

                                                    Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                    Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                    References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                    Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                    Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                    Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                    Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                    White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                    LMNOLMNOengcom httpwwwlmnoengcom

                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    bull

                                                    Circular Pressurized Water Pipes with Pump Curve

                                                    (Hazen Williams)

                                                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                    (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                    ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                    curve Darcy-Weisbach with pump curve

                                                    Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                    Register to enable Calculate button

                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                    Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                    IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                    function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                    manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                    Equations and Methodology Back to Calculations

                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                    calculation will look like

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                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                    Variables Units L=length P=pressure T=time Back to Calculations

                                                    A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                    g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                    hf = Major losses for entire pipe [L]

                                                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                    hm = Minor losses for entire pipe [L]

                                                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                    k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                    L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                    program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                    location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                    zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                    this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                    Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                    available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                    and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                    Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                    Material C Material C

                                                    Asbestos Cement 140 Copper 130-140

                                                    Brass 130-140 Galvanized iron 120

                                                    Brick sewer 100 Glass 140

                                                    Cast-Iron Lead 130-140

                                                    New unlined 130 Plastic 140-150

                                                    10 yr old 107-113 Steel

                                                    20 yr old 89-100 Coal-tar enamel lined 145-150

                                                    30 yr old 75-90 New unlined 140-150

                                                    40 yr old 64-83 Riveted 110

                                                    ConcreteConcrete-lined

                                                    Steel forms 140 Tin 130

                                                    Wooden forms 120 Vitrif clay (good condition) 110-140

                                                    Centrifugally spun 135 Wood stave (avg condition) 120

                                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                    Fitting K Fitting K

                                                    Valves Elbows

                                                    Globe fully open 10 Regular 90deg flanged 03

                                                    Angle fully open 2 Regular 90deg threaded 15

                                                    Gate fully open 015 Long radius 90deg flanged 02

                                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    Gate 34 closed 17 Regular 45deg threaded 04

                                                    Swing check forward flow 2

                                                    Swing check backward flow infinity Tees

                                                    Line flow flanged 02

                                                    180deg return bends Line flow threaded 09

                                                    Flanged 02 Branch flow flanged 10

                                                    Threaded 15 Branch flow threaded 20

                                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                    Square Connection 05 Square Connection 10

                                                    Rounded Connection 02 Rounded Connection 10

                                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                    Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                    entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                    One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                    entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                    P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                    to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                    the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                    and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                    pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                    result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                    be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                    lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                    LMNOLMNOengcom httpwwwlmnoengcom

                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                    bull

                                                    Trapezoidal Open Channel Design Calculation

                                                    Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                    Froude number Manning coefficient channel slope

                                                    To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                    Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                    Register to enable Calculate button

                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                    Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                    IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                    beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                    The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                    Variables [] indicates dimensions To calculation

                                                    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                    divided by vertical distance

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                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                    Oslash = Angle formed by S

                                                    Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                    Material Manning n Material Manning n

                                                    Natural Streams Excavated Earth Channels

                                                    Clean and Straight 0030 Clean 0022

                                                    Major Rivers 0035 Gravelly 0025

                                                    Sluggish with Deep Pools 0040 Weedy 0030

                                                    Stony Cobbles 0035

                                                    Metals Floodplains

                                                    Brass 0011 Pasture Farmland 0035

                                                    Cast Iron 0013 Light Brush 0050

                                                    Smooth Steel 0012 Heavy Brush 0075

                                                    Corrugated Metal 0022 Trees 015

                                                    Non-Metals

                                                    Glass 0010 Finished Concrete 0012

                                                    Clay Tile 0014 Unfinished Concrete 0014

                                                    Brickwork 0015 Gravel 0029

                                                    Asphalt 0016 Earth 0025

                                                    Masonry 0025 Planed Wood 0012

                                                    Unplaned Wood 0013

                                                    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                    Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                    The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                    cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                    simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                    The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                    References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                    a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                    Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                    French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                    Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                    7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                    View the version 40 New Features List

                                                    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                    Learn More About AFT Impulse 40

                                                    Details Views Brochure Demo

                                                    copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                                        • Circular Culvert Design Calculations Software Equations
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                                                                • Culvert Design Inlet and Outlet Control
                                                                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                        • Design of Circular Water Pipes using Hazen Williams Equation
                                                                            • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                    • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                        • Gradually Varied Flow Calculation Backwater profile
                                                                                            • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                                • Hydraulic Jump Calculation
                                                                                                    • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                        • Manning Equation
                                                                                                            • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                • Non-Circular Open Channel Geometry
                                                                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                            • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                      Hydraulic Jump Calculation

                                                      Register to enable Calculate button

                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                      Equations

                                                      Equations for hydraulic jump in horizontal rectangular channel (Chaudhry 1993 Chow 1959)

                                                      V=Q(yB) F=V(gy)05 y2y1 = 05 [(1+8F12 )05 - 1]

                                                      L = 220 y1 tanh[(F1-1)22] h = (y2-y1)3 (4y1y2)

                                                      where (subscript 1 indicates upstream of jump subscript 2 indicates downstream of jump)B=Channel width (m) F=Froude number (dimension-less) g=acceleration due to gravity (98066 ms2) h=Head loss (m) L=Length of jump (m) Q=Discharge (m3s) tanh=Hyperbolic tangent trigonometric function V=Velocity (ms) y=Water depth (m)

                                                      Note Equations require consistent units such as ft and seconds or meters and seconds LMNO Engineering calculation allows a wide variety of other units Most units are self-explanatory MGD is Millions Gallons (US) per Day

                                                      What is a Hydraulic Jump

                                                      A hydraulic jump occurs when the upstream flow is supercritical (Fgt1) To have a jump there must be a flow impediment downstream The downstream impediment could be a weir a bridge abutment a dam or simply channel friction Water depth increases during a hydraulic jump and energy is dissipated as turbulence Often engineers will purposely install impediments in channels in order to force jumps to occur Mixing of coagulant chemicals in water treatment plants is often aided by hydraulic jumps Concrete blocks may be installed in a channel downstream of a spillway in order to force a jump to occur thereby reducing the velocity and energy of the water Flow will go from supercritical (Fgt1) to subcritical (Flt1) over a jump

                                                      According to Chow (1959) a strong jump occurs when F1gt9 a steady jump occurs when 45ltF1lt9 an

                                                      oscillating jump occurs when 25ltF1lt45 a weak jump occurs when 17ltF1lt25 and an undular jump

                                                      occurs when 1ltF1lt17 According to Chaudhry (1993) the best jumps occur when 45ltF1lt9

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                                                      Hydraulic Jump Calculation

                                                      MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                                      Need F1 gt1 Upstream flow must be supercritical

                                                      ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                                      copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                      LMNOLMNOengcom httpwwwlmnoengcom

                                                      fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                                      Manning Equation

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                                                      Mannings Equation Calculator Software The open channel flow software website

                                                      LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                                      Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                      The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                                      and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                                      The product AP is also known as the hydraulic radius Rh

                                                      fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                                      Non-Circular Open Channel Geometry

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                                                      Geometric Calculations for Non-Circular Partially Filled Channels

                                                      The open channel flow calculations software website

                                                      Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                      You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                                      Equations (note that R=AP)

                                                      fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                                      Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                      losses

                                                      Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                      pipe Dont have to use all the pipes or nodes

                                                      To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                      Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                      Register to fully enable Calculate button

                                                      Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                      Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                      IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                      Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                      The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                      Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                      Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                      1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                      Pipe flows are adjusted iteratively using the following equation

                                                      until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                      Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                      Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                      Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                      where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                      Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                      Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                      Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                      Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                      For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                      The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                      ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                      1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                      pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                      2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                      Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                      Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                      Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                      A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                      n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                      Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                      Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                      References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                      Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                      LMNOLMNOengcom httpwwwlmnoengcom

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                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

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                                                      Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                      Weisbach - Moody friction losses)

                                                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                      (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                      Parabolic shaped pump curve is formed from the two points

                                                      ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                      curve Hazen-Williams with pump curve

                                                      Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                      Register to enable Calculate button

                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                      Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                      IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                      A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                      For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                      (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                      Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                      Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                      calculation will look like

                                                      The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                      Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                      Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                      is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                      defined for liquids

                                                      Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                      is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                      A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                      hf = Major losses for entire pipe [L] Also known as friction losses

                                                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                      hm = Minor losses for entire pipe [L]

                                                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                      K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                      for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                      P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                      location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                      zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                      V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                      this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                      v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                      Fitting K Fitting K

                                                      Valves Elbows

                                                      Globe fully open 10 Regular 90deg flanged 03

                                                      Angle fully open 2 Regular 90deg threaded 15

                                                      Gate fully open 015 Long radius 90deg flanged 02

                                                      Gate 14 closed 026 Long radius 90deg threaded 07

                                                      Gate 12 closed 21 Long radius 45deg threaded 02

                                                      Gate 34 closed 17 Regular 45deg threaded 04

                                                      Swing check forward flow 2

                                                      Swing check backward flow infinity Tees

                                                      Line flow flanged 02

                                                      180deg return bends Line flow threaded 09

                                                      Flanged 02 Branch flow flanged 10

                                                      Threaded 15 Branch flow threaded 20

                                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                      Square Connection 05 Square Connection 10

                                                      Rounded Connection 02 Rounded Connection 10

                                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                      Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                      The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                      Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                      the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                      Other messagesK must be gt=1 If Q known Solve for D and V

                                                      3=0 then K must be gt 1 in order to solve

                                                      Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                      reservoirs are defined to be at zero pressure thus zero pressure difference

                                                      Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                      Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                      References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                      Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                      Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                      Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                      Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                      White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                      LMNOLMNOengcom httpwwwlmnoengcom

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                      Circular Pressurized Water Pipes with Pump Curve

                                                      (Hazen Williams)

                                                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                      (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                      ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                      curve Darcy-Weisbach with pump curve

                                                      Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                      Register to enable Calculate button

                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                      Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                      IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                      function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                      manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                      Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                      Equations and Methodology Back to Calculations

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                      The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                      calculation will look like

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                      Variables Units L=length P=pressure T=time Back to Calculations

                                                      A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                      g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                      hf = Major losses for entire pipe [L]

                                                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                      hm = Minor losses for entire pipe [L]

                                                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                      k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                      L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                      different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                      program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                      location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                      zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                      this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                      Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                      available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                      and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                      curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                      Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                      Material C Material C

                                                      Asbestos Cement 140 Copper 130-140

                                                      Brass 130-140 Galvanized iron 120

                                                      Brick sewer 100 Glass 140

                                                      Cast-Iron Lead 130-140

                                                      New unlined 130 Plastic 140-150

                                                      10 yr old 107-113 Steel

                                                      20 yr old 89-100 Coal-tar enamel lined 145-150

                                                      30 yr old 75-90 New unlined 140-150

                                                      40 yr old 64-83 Riveted 110

                                                      ConcreteConcrete-lined

                                                      Steel forms 140 Tin 130

                                                      Wooden forms 120 Vitrif clay (good condition) 110-140

                                                      Centrifugally spun 135 Wood stave (avg condition) 120

                                                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                      Fitting K Fitting K

                                                      Valves Elbows

                                                      Globe fully open 10 Regular 90deg flanged 03

                                                      Angle fully open 2 Regular 90deg threaded 15

                                                      Gate fully open 015 Long radius 90deg flanged 02

                                                      Gate 14 closed 026 Long radius 90deg threaded 07

                                                      Gate 12 closed 21 Long radius 45deg threaded 02

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                      Gate 34 closed 17 Regular 45deg threaded 04

                                                      Swing check forward flow 2

                                                      Swing check backward flow infinity Tees

                                                      Line flow flanged 02

                                                      180deg return bends Line flow threaded 09

                                                      Flanged 02 Branch flow flanged 10

                                                      Threaded 15 Branch flow threaded 20

                                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                      Square Connection 05 Square Connection 10

                                                      Rounded Connection 02 Rounded Connection 10

                                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                      Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                      entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                      One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                      entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                      P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                      to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                      the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                      and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                      pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                      result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                      be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                      lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                      LMNOLMNOengcom httpwwwlmnoengcom

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                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                      Trapezoidal Open Channel Design Calculation

                                                      Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                      Froude number Manning coefficient channel slope

                                                      To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                      Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                                      Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                      IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                      beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                      The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                      In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                      Variables [] indicates dimensions To calculation

                                                      A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                      divided by vertical distance

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                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                      Oslash = Angle formed by S

                                                      Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                      Material Manning n Material Manning n

                                                      Natural Streams Excavated Earth Channels

                                                      Clean and Straight 0030 Clean 0022

                                                      Major Rivers 0035 Gravelly 0025

                                                      Sluggish with Deep Pools 0040 Weedy 0030

                                                      Stony Cobbles 0035

                                                      Metals Floodplains

                                                      Brass 0011 Pasture Farmland 0035

                                                      Cast Iron 0013 Light Brush 0050

                                                      Smooth Steel 0012 Heavy Brush 0075

                                                      Corrugated Metal 0022 Trees 015

                                                      Non-Metals

                                                      Glass 0010 Finished Concrete 0012

                                                      Clay Tile 0014 Unfinished Concrete 0014

                                                      Brickwork 0015 Gravel 0029

                                                      Asphalt 0016 Earth 0025

                                                      Masonry 0025 Planed Wood 0012

                                                      Unplaned Wood 0013

                                                      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                      Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                      The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                      cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                      simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                      The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                      References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                      a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                      Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                      French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                      Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                      7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                      Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                      Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                      View the version 40 New Features List

                                                      Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                      AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                      From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                      View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                      Learn More About AFT Impulse 40

                                                      Details Views Brochure Demo

                                                      copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                        • Local Disk
                                                          • Circular Culvert Design Calculations Software Equations
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                                                                  • Culvert Design Inlet and Outlet Control
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                                                                          • Design of Circular Water Pipes using Hazen Williams Equation
                                                                              • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                  • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                      • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                          • Gradually Varied Flow Calculation Backwater profile
                                                                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                                  • Hydraulic Jump Calculation
                                                                                                      • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                          • Manning Equation
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                                                                                                                  • Non-Circular Open Channel Geometry
                                                                                                                      • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                              • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                        • Local Disk
                                                                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                        Hydraulic Jump Calculation

                                                        MessagesNeed Bgt0 Channel width must be a positive numberNeed Qgt0 Discharge must be positiveNeed y1gt0 Upstream depth must be positive

                                                        Need F1 gt1 Upstream flow must be supercritical

                                                        ReferencesChaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc

                                                        copy 2004 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                        LMNOLMNOengcom httpwwwlmnoengcom

                                                        fileE|engineeringhydraulicsHydraulic20Jump20Calculationhtm (3 of 3)12112007 40633 PM

                                                        Manning Equation

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                                                        Mannings Equation Calculator Software The open channel flow software website

                                                        LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                                        Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                        The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                                        and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                                        The product AP is also known as the hydraulic radius Rh

                                                        fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                                        Non-Circular Open Channel Geometry

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                                                        Geometric Calculations for Non-Circular Partially Filled Channels

                                                        The open channel flow calculations software website

                                                        Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                        You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                                        Equations (note that R=AP)

                                                        fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                                        Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                        losses

                                                        Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                        pipe Dont have to use all the pipes or nodes

                                                        To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                        Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                        Register to fully enable Calculate button

                                                        Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                        Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                        IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                        Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                        The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                        Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                        Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                        1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                        Pipe flows are adjusted iteratively using the following equation

                                                        until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                        Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                        Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                        Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                        where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                        Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                        Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                        Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                        Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                        For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                        The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                        ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                        1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                        pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                        2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                        Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                        Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                        Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                        A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                        n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                        Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                        Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                        References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                        Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                        LMNOLMNOengcom httpwwwlmnoengcom

                                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        bull

                                                        Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                        Weisbach - Moody friction losses)

                                                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                        (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                        Parabolic shaped pump curve is formed from the two points

                                                        ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                        curve Hazen-Williams with pump curve

                                                        Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                        Register to enable Calculate button

                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                        Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                        IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                        A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                        For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                        (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                        Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                        calculation will look like

                                                        The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                        Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                        Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                        is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                        defined for liquids

                                                        Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                        A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                        hf = Major losses for entire pipe [L] Also known as friction losses

                                                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                        hm = Minor losses for entire pipe [L]

                                                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                        K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                        for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                        P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                        location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                        zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                        this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                        v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                        Fitting K Fitting K

                                                        Valves Elbows

                                                        Globe fully open 10 Regular 90deg flanged 03

                                                        Angle fully open 2 Regular 90deg threaded 15

                                                        Gate fully open 015 Long radius 90deg flanged 02

                                                        Gate 14 closed 026 Long radius 90deg threaded 07

                                                        Gate 12 closed 21 Long radius 45deg threaded 02

                                                        Gate 34 closed 17 Regular 45deg threaded 04

                                                        Swing check forward flow 2

                                                        Swing check backward flow infinity Tees

                                                        Line flow flanged 02

                                                        180deg return bends Line flow threaded 09

                                                        Flanged 02 Branch flow flanged 10

                                                        Threaded 15 Branch flow threaded 20

                                                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        Square Connection 05 Square Connection 10

                                                        Rounded Connection 02 Rounded Connection 10

                                                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                        Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                        The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                        Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                        the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                        Other messagesK must be gt=1 If Q known Solve for D and V

                                                        3=0 then K must be gt 1 in order to solve

                                                        Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                        reservoirs are defined to be at zero pressure thus zero pressure difference

                                                        Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                        Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                        References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                        Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                        Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                        Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                        Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                        White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                        Circular Pressurized Water Pipes with Pump Curve

                                                        (Hazen Williams)

                                                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                        (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                        ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                        curve Darcy-Weisbach with pump curve

                                                        Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

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                                                        Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                        IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                        function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                        manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                        Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                        Equations and Methodology Back to Calculations

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                        The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                        calculation will look like

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                        Variables Units L=length P=pressure T=time Back to Calculations

                                                        A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                        g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                        hf = Major losses for entire pipe [L]

                                                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                        hm = Minor losses for entire pipe [L]

                                                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                        k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                        L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                        different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                        program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                        location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                        zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                        this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                        Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                        available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                        and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                        curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                        Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                        Material C Material C

                                                        Asbestos Cement 140 Copper 130-140

                                                        Brass 130-140 Galvanized iron 120

                                                        Brick sewer 100 Glass 140

                                                        Cast-Iron Lead 130-140

                                                        New unlined 130 Plastic 140-150

                                                        10 yr old 107-113 Steel

                                                        20 yr old 89-100 Coal-tar enamel lined 145-150

                                                        30 yr old 75-90 New unlined 140-150

                                                        40 yr old 64-83 Riveted 110

                                                        ConcreteConcrete-lined

                                                        Steel forms 140 Tin 130

                                                        Wooden forms 120 Vitrif clay (good condition) 110-140

                                                        Centrifugally spun 135 Wood stave (avg condition) 120

                                                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                        Fitting K Fitting K

                                                        Valves Elbows

                                                        Globe fully open 10 Regular 90deg flanged 03

                                                        Angle fully open 2 Regular 90deg threaded 15

                                                        Gate fully open 015 Long radius 90deg flanged 02

                                                        Gate 14 closed 026 Long radius 90deg threaded 07

                                                        Gate 12 closed 21 Long radius 45deg threaded 02

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                        Gate 34 closed 17 Regular 45deg threaded 04

                                                        Swing check forward flow 2

                                                        Swing check backward flow infinity Tees

                                                        Line flow flanged 02

                                                        180deg return bends Line flow threaded 09

                                                        Flanged 02 Branch flow flanged 10

                                                        Threaded 15 Branch flow threaded 20

                                                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                        Square Connection 05 Square Connection 10

                                                        Rounded Connection 02 Rounded Connection 10

                                                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                        Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                        entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                        One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                        entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                        P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                        to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                        the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                        and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                        pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                        result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                        be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                        lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                        Trapezoidal Open Channel Design Calculation

                                                        Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                        Froude number Manning coefficient channel slope

                                                        To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                        Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

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                                                        Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                        IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                        beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                        The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                        In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                        Variables [] indicates dimensions To calculation

                                                        A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                        divided by vertical distance

                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                        Oslash = Angle formed by S

                                                        Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                        Material Manning n Material Manning n

                                                        Natural Streams Excavated Earth Channels

                                                        Clean and Straight 0030 Clean 0022

                                                        Major Rivers 0035 Gravelly 0025

                                                        Sluggish with Deep Pools 0040 Weedy 0030

                                                        Stony Cobbles 0035

                                                        Metals Floodplains

                                                        Brass 0011 Pasture Farmland 0035

                                                        Cast Iron 0013 Light Brush 0050

                                                        Smooth Steel 0012 Heavy Brush 0075

                                                        Corrugated Metal 0022 Trees 015

                                                        Non-Metals

                                                        Glass 0010 Finished Concrete 0012

                                                        Clay Tile 0014 Unfinished Concrete 0014

                                                        Brickwork 0015 Gravel 0029

                                                        Asphalt 0016 Earth 0025

                                                        Masonry 0025 Planed Wood 0012

                                                        Unplaned Wood 0013

                                                        Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                        Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                        Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                        Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                        The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                        cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                        simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                        The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                        References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                        a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                        Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                        French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                        Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                        7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                        Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                        Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                        View the version 40 New Features List

                                                        Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                        AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                        components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                        From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                        View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                        Learn More About AFT Impulse 40

                                                        Details Views Brochure Demo

                                                        copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                        • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                                            • Circular Culvert Design Calculations Software Equations
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                                                                    • Culvert Design Inlet and Outlet Control
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                                                                            • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                    • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                        • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                            • Gradually Varied Flow Calculation Backwater profile
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                                                                                                    • Hydraulic Jump Calculation
                                                                                                        • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                            • Manning Equation
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                                                                                                                    • Non-Circular Open Channel Geometry
                                                                                                                        • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                            • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                    • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                            • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                    • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                        • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                            • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                          Manning Equation

                                                          bull

                                                          Mannings Equation Calculator Software The open channel flow software website

                                                          LMNO Engineering Home Page Manning n values Unit Conversions Trouble printing More calculations Design of Rectangular Channels Design of Trapezoidal Channels

                                                          Circular Culverts using Manning Equation Culvert Design using Inlet and Outlet Control Q=VA simple flowrate calculator

                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                          The Manning Equation is the most commonly used equation to analyze open channel flows It is a semi-empirical equation for simulating water flows in channels and culverts where the water is open to the atmosphere ie not flowing under pressure and was first presented in 1889 by Robert Manning The channel can be any shape - circular rectangular triangular etc The units in the Manning equation appear to be inconsistent however the value k has hidden units in it to make the equation consistent The Manning Equation was developed for uniform steady state flow (see Discussion and References for Open Channel Flow) S is the slope of the energy grade line and S=hfL where hf is energy (head) loss

                                                          and L is the length of the channel or reach For uniform steady flows the energy grade line = the slope of the water surface = the slope of the bottom of the channel

                                                          The product AP is also known as the hydraulic radius Rh

                                                          fileE|engineeringhydraulicsManning20Equationhtm12112007 40702 PM

                                                          Non-Circular Open Channel Geometry

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                                                          Geometric Calculations for Non-Circular Partially Filled Channels

                                                          The open channel flow calculations software website

                                                          Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                          You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                                          Equations (note that R=AP)

                                                          fileE|engineeringhydraulicsNon-Circular20Open20Channel20Geometryhtm12112007 40719 PM

                                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                          bull

                                                          Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                          losses

                                                          Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                          pipe Dont have to use all the pipes or nodes

                                                          To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                          Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                          Register to fully enable Calculate button

                                                          Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                          Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                          IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                          Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                          The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                          Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                          Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                          1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                          Pipe flows are adjusted iteratively using the following equation

                                                          until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                          Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                          Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                          Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                          where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                          Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                          Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                          Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                          Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                          For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                          The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                          ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                          1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                          pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                          2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                          Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                          Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                          Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                          A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                          n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                          Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                          Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                          References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                          Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                          Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                          LMNOLMNOengcom httpwwwlmnoengcom

                                                          fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          bull

                                                          Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                          Weisbach - Moody friction losses)

                                                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                          (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                          Parabolic shaped pump curve is formed from the two points

                                                          ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                          curve Hazen-Williams with pump curve

                                                          Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                          Register to enable Calculate button

                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                          Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                          IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                          A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                          For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                          (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                          Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                          calculation will look like

                                                          The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                          Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                          Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                          is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                          defined for liquids

                                                          Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                          A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                          hf = Major losses for entire pipe [L] Also known as friction losses

                                                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                          hm = Minor losses for entire pipe [L]

                                                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                          K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                          for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                          P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                          location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                          zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                          this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                          v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                          Fitting K Fitting K

                                                          Valves Elbows

                                                          Globe fully open 10 Regular 90deg flanged 03

                                                          Angle fully open 2 Regular 90deg threaded 15

                                                          Gate fully open 015 Long radius 90deg flanged 02

                                                          Gate 14 closed 026 Long radius 90deg threaded 07

                                                          Gate 12 closed 21 Long radius 45deg threaded 02

                                                          Gate 34 closed 17 Regular 45deg threaded 04

                                                          Swing check forward flow 2

                                                          Swing check backward flow infinity Tees

                                                          Line flow flanged 02

                                                          180deg return bends Line flow threaded 09

                                                          Flanged 02 Branch flow flanged 10

                                                          Threaded 15 Branch flow threaded 20

                                                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          Square Connection 05 Square Connection 10

                                                          Rounded Connection 02 Rounded Connection 10

                                                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                          Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                          The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                          Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                          the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                          Other messagesK must be gt=1 If Q known Solve for D and V

                                                          3=0 then K must be gt 1 in order to solve

                                                          Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                          reservoirs are defined to be at zero pressure thus zero pressure difference

                                                          Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                          Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                          References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                          Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                          Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                          Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                          Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                          White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                          LMNOLMNOengcom httpwwwlmnoengcom

                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          bull

                                                          Circular Pressurized Water Pipes with Pump Curve

                                                          (Hazen Williams)

                                                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                          (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                          temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                          ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                          curve Darcy-Weisbach with pump curve

                                                          Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                          Register to enable Calculate button

                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                          Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                          IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                          function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                          manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                          Equations and Methodology Back to Calculations

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                          calculation will look like

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                          Variables Units L=length P=pressure T=time Back to Calculations

                                                          A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                          g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                          hf = Major losses for entire pipe [L]

                                                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                          hm = Minor losses for entire pipe [L]

                                                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                          k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                          L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                          program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                          location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                          zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                          this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                          Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                          available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                          and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                          Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                          Material C Material C

                                                          Asbestos Cement 140 Copper 130-140

                                                          Brass 130-140 Galvanized iron 120

                                                          Brick sewer 100 Glass 140

                                                          Cast-Iron Lead 130-140

                                                          New unlined 130 Plastic 140-150

                                                          10 yr old 107-113 Steel

                                                          20 yr old 89-100 Coal-tar enamel lined 145-150

                                                          30 yr old 75-90 New unlined 140-150

                                                          40 yr old 64-83 Riveted 110

                                                          ConcreteConcrete-lined

                                                          Steel forms 140 Tin 130

                                                          Wooden forms 120 Vitrif clay (good condition) 110-140

                                                          Centrifugally spun 135 Wood stave (avg condition) 120

                                                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                          Fitting K Fitting K

                                                          Valves Elbows

                                                          Globe fully open 10 Regular 90deg flanged 03

                                                          Angle fully open 2 Regular 90deg threaded 15

                                                          Gate fully open 015 Long radius 90deg flanged 02

                                                          Gate 14 closed 026 Long radius 90deg threaded 07

                                                          Gate 12 closed 21 Long radius 45deg threaded 02

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          Gate 34 closed 17 Regular 45deg threaded 04

                                                          Swing check forward flow 2

                                                          Swing check backward flow infinity Tees

                                                          Line flow flanged 02

                                                          180deg return bends Line flow threaded 09

                                                          Flanged 02 Branch flow flanged 10

                                                          Threaded 15 Branch flow threaded 20

                                                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                          Square Connection 05 Square Connection 10

                                                          Rounded Connection 02 Rounded Connection 10

                                                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                          Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                          entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                          One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                          entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                          P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                          to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                          the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                          and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                          pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                          result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                          be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                          lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                          LMNOLMNOengcom httpwwwlmnoengcom

                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                          bull

                                                          Trapezoidal Open Channel Design Calculation

                                                          Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                          Froude number Manning coefficient channel slope

                                                          To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                          Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

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                                                          Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                          IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                          beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                          The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                          In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                          Variables [] indicates dimensions To calculation

                                                          A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                          divided by vertical distance

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                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                          Oslash = Angle formed by S

                                                          Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                          Material Manning n Material Manning n

                                                          Natural Streams Excavated Earth Channels

                                                          Clean and Straight 0030 Clean 0022

                                                          Major Rivers 0035 Gravelly 0025

                                                          Sluggish with Deep Pools 0040 Weedy 0030

                                                          Stony Cobbles 0035

                                                          Metals Floodplains

                                                          Brass 0011 Pasture Farmland 0035

                                                          Cast Iron 0013 Light Brush 0050

                                                          Smooth Steel 0012 Heavy Brush 0075

                                                          Corrugated Metal 0022 Trees 015

                                                          Non-Metals

                                                          Glass 0010 Finished Concrete 0012

                                                          Clay Tile 0014 Unfinished Concrete 0014

                                                          Brickwork 0015 Gravel 0029

                                                          Asphalt 0016 Earth 0025

                                                          Masonry 0025 Planed Wood 0012

                                                          Unplaned Wood 0013

                                                          Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                          Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                          Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                          Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                          The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                          cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                          simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                          The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                          References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                          a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                          c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                          e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                          Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                          French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                          d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                          Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                          b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                          7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                          Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

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                                                          Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                          AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                          components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                          From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

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                                                          Details Views Brochure Demo

                                                          copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                          • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                                              • Circular Culvert Design Calculations Software Equations
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                                                                      • Culvert Design Inlet and Outlet Control
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                                                                              • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                                                              • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
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                                                                                                                                      • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                              • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                      • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
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                                                                                                                                                              • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                            Non-Circular Open Channel Geometry

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                                                            Geometric Calculations for Non-Circular Partially Filled Channels

                                                            The open channel flow calculations software website

                                                            Manning Equation Calculator Design of Rectangular Channels Calculation Unit Conversions LMNO Engineering Home Page Trouble printing

                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                            You may enter numbers in any units so long as you are consistent (L) means that the variable has units of length (eg meters) (L2) means that the variable has units of length squared (eg m2)

                                                            Equations (note that R=AP)

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                                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                                            Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                            losses

                                                            Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                            pipe Dont have to use all the pipes or nodes

                                                            To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                            Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                            Register to fully enable Calculate button

                                                            Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                            Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                            IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                            Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                            The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

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                                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                            Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                            Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                            1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                            Pipe flows are adjusted iteratively using the following equation

                                                            until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                            Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                            Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                            Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                            where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                            Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                            Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                            Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                            Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                            For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                            The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                            ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                            1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                            pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                            2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                            Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                            Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                            Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                            A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                            n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                            Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                            Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                            References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                            Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                            Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                            LMNOLMNOengcom httpwwwlmnoengcom

                                                            fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            bull

                                                            Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                            Weisbach - Moody friction losses)

                                                            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                            (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                            Parabolic shaped pump curve is formed from the two points

                                                            ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                            curve Hazen-Williams with pump curve

                                                            Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                            Register to enable Calculate button

                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                            Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                            IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                            A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                            For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                            (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                            Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                            calculation will look like

                                                            The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                            Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                            Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                            is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                            defined for liquids

                                                            Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                            A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                            hf = Major losses for entire pipe [L] Also known as friction losses

                                                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                            hm = Minor losses for entire pipe [L]

                                                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                            K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                            for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                            P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                            location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                            zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                            this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                            v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                            Fitting K Fitting K

                                                            Valves Elbows

                                                            Globe fully open 10 Regular 90deg flanged 03

                                                            Angle fully open 2 Regular 90deg threaded 15

                                                            Gate fully open 015 Long radius 90deg flanged 02

                                                            Gate 14 closed 026 Long radius 90deg threaded 07

                                                            Gate 12 closed 21 Long radius 45deg threaded 02

                                                            Gate 34 closed 17 Regular 45deg threaded 04

                                                            Swing check forward flow 2

                                                            Swing check backward flow infinity Tees

                                                            Line flow flanged 02

                                                            180deg return bends Line flow threaded 09

                                                            Flanged 02 Branch flow flanged 10

                                                            Threaded 15 Branch flow threaded 20

                                                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            Square Connection 05 Square Connection 10

                                                            Rounded Connection 02 Rounded Connection 10

                                                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                            Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                            The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                            Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                            the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                            Other messagesK must be gt=1 If Q known Solve for D and V

                                                            3=0 then K must be gt 1 in order to solve

                                                            Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                            reservoirs are defined to be at zero pressure thus zero pressure difference

                                                            Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                            Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                            References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                            Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                            Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                            fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                            Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                            Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                            White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                            LMNOLMNOengcom httpwwwlmnoengcom

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                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            bull

                                                            Circular Pressurized Water Pipes with Pump Curve

                                                            (Hazen Williams)

                                                            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                            (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                            temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                            ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                            curve Darcy-Weisbach with pump curve

                                                            Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                            Register to enable Calculate button

                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                            Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                            IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                            function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                            manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                            Equations and Methodology Back to Calculations

                                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                            calculation will look like

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                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                            Variables Units L=length P=pressure T=time Back to Calculations

                                                            A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                            g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                            hf = Major losses for entire pipe [L]

                                                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                            hm = Minor losses for entire pipe [L]

                                                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                            k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                            L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                            program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                            location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                            zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                            this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                            Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                            available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                            and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                            Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                            Material C Material C

                                                            Asbestos Cement 140 Copper 130-140

                                                            Brass 130-140 Galvanized iron 120

                                                            Brick sewer 100 Glass 140

                                                            Cast-Iron Lead 130-140

                                                            New unlined 130 Plastic 140-150

                                                            10 yr old 107-113 Steel

                                                            20 yr old 89-100 Coal-tar enamel lined 145-150

                                                            30 yr old 75-90 New unlined 140-150

                                                            40 yr old 64-83 Riveted 110

                                                            ConcreteConcrete-lined

                                                            Steel forms 140 Tin 130

                                                            Wooden forms 120 Vitrif clay (good condition) 110-140

                                                            Centrifugally spun 135 Wood stave (avg condition) 120

                                                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                            Fitting K Fitting K

                                                            Valves Elbows

                                                            Globe fully open 10 Regular 90deg flanged 03

                                                            Angle fully open 2 Regular 90deg threaded 15

                                                            Gate fully open 015 Long radius 90deg flanged 02

                                                            Gate 14 closed 026 Long radius 90deg threaded 07

                                                            Gate 12 closed 21 Long radius 45deg threaded 02

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                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            Gate 34 closed 17 Regular 45deg threaded 04

                                                            Swing check forward flow 2

                                                            Swing check backward flow infinity Tees

                                                            Line flow flanged 02

                                                            180deg return bends Line flow threaded 09

                                                            Flanged 02 Branch flow flanged 10

                                                            Threaded 15 Branch flow threaded 20

                                                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                            Square Connection 05 Square Connection 10

                                                            Rounded Connection 02 Rounded Connection 10

                                                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                            Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                            entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                            One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                            entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                            P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                            to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                            the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                            and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                            pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                            result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                            be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                            lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                            LMNOLMNOengcom httpwwwlmnoengcom

                                                            fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                            Trapezoidal Open Channel Design Calculation

                                                            Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                            Froude number Manning coefficient channel slope

                                                            To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                            Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                            Register to enable Calculate button

                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                            Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                            IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                            beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                            The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                            In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                            Variables [] indicates dimensions To calculation

                                                            A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                            divided by vertical distance

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                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                            Oslash = Angle formed by S

                                                            Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                            Material Manning n Material Manning n

                                                            Natural Streams Excavated Earth Channels

                                                            Clean and Straight 0030 Clean 0022

                                                            Major Rivers 0035 Gravelly 0025

                                                            Sluggish with Deep Pools 0040 Weedy 0030

                                                            Stony Cobbles 0035

                                                            Metals Floodplains

                                                            Brass 0011 Pasture Farmland 0035

                                                            Cast Iron 0013 Light Brush 0050

                                                            Smooth Steel 0012 Heavy Brush 0075

                                                            Corrugated Metal 0022 Trees 015

                                                            Non-Metals

                                                            Glass 0010 Finished Concrete 0012

                                                            Clay Tile 0014 Unfinished Concrete 0014

                                                            Brickwork 0015 Gravel 0029

                                                            Asphalt 0016 Earth 0025

                                                            Masonry 0025 Planed Wood 0012

                                                            Unplaned Wood 0013

                                                            Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                            Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                            Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                            Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                            The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                            cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                            simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                            The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                            References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                            a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                            c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                            e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                            Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                            French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                            d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                            Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                            b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                            7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                            Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                            Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                            View the version 40 New Features List

                                                            Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                            AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                            components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                            From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                            View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                            Learn More About AFT Impulse 40

                                                            Details Views Brochure Demo

                                                            copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                            • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                              • Local Disk
                                                                • Circular Culvert Design Calculations Software Equations
                                                                    • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                      • Local Disk
                                                                        • Culvert Design Inlet and Outlet Control
                                                                            • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                              • Local Disk
                                                                                • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                    • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                      • Local Disk
                                                                                        • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                            • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                • Gradually Varied Flow Calculation Backwater profile
                                                                                                    • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                      • Local Disk
                                                                                                        • Hydraulic Jump Calculation
                                                                                                            • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                              • Local Disk
                                                                                                                • Manning Equation
                                                                                                                    • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                        • Non-Circular Open Channel Geometry
                                                                                                                            • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                      • Local Disk
                                                                                                                                        • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                    • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                      • Local Disk
                                                                                                                                                        • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                            • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                                • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

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                                                              Pipe Network CalculatorDarcy Weisbach or Hazen Williams friction

                                                              losses

                                                              Compute pressure and hydraulic head at each node and flow in each pipe Enter node flows elevations pressure Select Darcy Weisbach (Moody diagram) or Hazen Williams friction losses Include minor losses by equivalent length of

                                                              pipe Dont have to use all the pipes or nodes

                                                              To Darcy-Weisbach single pipe Hazen-Williams single pipe Bypass Loop LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                              Enter positive values for inflows at nodes (negative values for outflows) Enter pipe diameter of 00 to make a pipe non-existent

                                                              Register to fully enable Calculate button

                                                              Demonstration mode for Fluid mercury Pipe material wood Losses Darcy-Weisbach Head loss units m of fluid Flow units m3s Diameter units meters Length units meters Elevation units meters Pressure units m of fluid Z+PS (hydraulic head) units m of fluid To enable other fluids materials units and Hazen-Williams losses please register Click shift-Reload on your browser to reload the default values

                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                              Topics on this page Introduction Equations and Methodology (Hardy Cross method friction losses (Darcy Weisbach and Hazen Williams) pressure computation minor losses and calculator) Applications Built-in fluid and material properties Units Variables Error Messages References

                                                              IntroductionPipe Network simulates steady flow of liquids or gases under pressure It can simulate city water systems car exhaust manifolds long pipelines with different diameter pipes in series parallel pipes groundwater flow into a slotted well screen soil vapor extraction well design and more Enter flows at nodes as positive for inflows and negative for outflows Inflows plus outflows must sum to 0 Enter one pressure in the system and all other pressures are computed All fields must have a number but the number can be 0 You do not need to use all the pipes or nodes Enter a diameter of 00 if a pipe does not exist If a node is surrounded on all sides by non-existent pipes the nodes flow must be entered as 00 The program allows a wide variety of units After clicking Calculate the arrows lt-- --gt v ^ indicate the direction of flow through each pipe (to the left right down or up)

                                                              Losses can be computed by either the Darcy-Weisbach or Hazen-Williams (HW) method selectable by clicking on the Roughness e drop-down menu If HW is used then the fluid must be selected as Water 20C (68F)

                                                              The HVRe output field is scrollable using the left and right arrow keys on your keyboard Velocity is in ms if metric units are selected for flowrate Q and fts if English units are selected for Q

                                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (1 of 6)12112007 40747 PM

                                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                              Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                              Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                              1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                              Pipe flows are adjusted iteratively using the following equation

                                                              until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                              Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                              Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                              Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                              where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                              Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                              Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                              Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                              Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                              For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                              The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                              ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                              1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

                                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (3 of 6)12112007 40747 PM

                                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                              pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                              2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                              Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                              Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                              Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                              A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                              n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

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                                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                              Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                              Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                              References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                              Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                              Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                              LMNOLMNOengcom httpwwwlmnoengcom

                                                              fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              bull

                                                              Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                              Weisbach - Moody friction losses)

                                                              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                              (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                              Parabolic shaped pump curve is formed from the two points

                                                              ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                              curve Hazen-Williams with pump curve

                                                              Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                              Register to enable Calculate button

                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                              Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                              IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                              A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                              For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                              (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                              Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                              calculation will look like

                                                              The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                              Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                              Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                              is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                              defined for liquids

                                                              Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                              A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                              hf = Major losses for entire pipe [L] Also known as friction losses

                                                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                              hm = Minor losses for entire pipe [L]

                                                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                              K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                              for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                              P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                              location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                              zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                              this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                              v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                              Fitting K Fitting K

                                                              Valves Elbows

                                                              Globe fully open 10 Regular 90deg flanged 03

                                                              Angle fully open 2 Regular 90deg threaded 15

                                                              Gate fully open 015 Long radius 90deg flanged 02

                                                              Gate 14 closed 026 Long radius 90deg threaded 07

                                                              Gate 12 closed 21 Long radius 45deg threaded 02

                                                              Gate 34 closed 17 Regular 45deg threaded 04

                                                              Swing check forward flow 2

                                                              Swing check backward flow infinity Tees

                                                              Line flow flanged 02

                                                              180deg return bends Line flow threaded 09

                                                              Flanged 02 Branch flow flanged 10

                                                              Threaded 15 Branch flow threaded 20

                                                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              Square Connection 05 Square Connection 10

                                                              Rounded Connection 02 Rounded Connection 10

                                                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                              Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                              The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                              Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                              the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                              Other messagesK must be gt=1 If Q known Solve for D and V

                                                              3=0 then K must be gt 1 in order to solve

                                                              Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                              reservoirs are defined to be at zero pressure thus zero pressure difference

                                                              Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                              Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                              References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                              Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                              Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                              Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                              Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                              White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                              LMNOLMNOengcom httpwwwlmnoengcom

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                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              bull

                                                              Circular Pressurized Water Pipes with Pump Curve

                                                              (Hazen Williams)

                                                              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                              (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                              temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                              ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                              curve Darcy-Weisbach with pump curve

                                                              Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                              Register to enable Calculate button

                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                              Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                              IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                              function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                              manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                              Equations and Methodology Back to Calculations

                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                              calculation will look like

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                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                              Variables Units L=length P=pressure T=time Back to Calculations

                                                              A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                              g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                              hf = Major losses for entire pipe [L]

                                                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                              hm = Minor losses for entire pipe [L]

                                                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                              k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                              L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                              program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                              location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                              zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                              this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                              Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                              available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                              and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                              Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                              Material C Material C

                                                              Asbestos Cement 140 Copper 130-140

                                                              Brass 130-140 Galvanized iron 120

                                                              Brick sewer 100 Glass 140

                                                              Cast-Iron Lead 130-140

                                                              New unlined 130 Plastic 140-150

                                                              10 yr old 107-113 Steel

                                                              20 yr old 89-100 Coal-tar enamel lined 145-150

                                                              30 yr old 75-90 New unlined 140-150

                                                              40 yr old 64-83 Riveted 110

                                                              ConcreteConcrete-lined

                                                              Steel forms 140 Tin 130

                                                              Wooden forms 120 Vitrif clay (good condition) 110-140

                                                              Centrifugally spun 135 Wood stave (avg condition) 120

                                                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                              Fitting K Fitting K

                                                              Valves Elbows

                                                              Globe fully open 10 Regular 90deg flanged 03

                                                              Angle fully open 2 Regular 90deg threaded 15

                                                              Gate fully open 015 Long radius 90deg flanged 02

                                                              Gate 14 closed 026 Long radius 90deg threaded 07

                                                              Gate 12 closed 21 Long radius 45deg threaded 02

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                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              Gate 34 closed 17 Regular 45deg threaded 04

                                                              Swing check forward flow 2

                                                              Swing check backward flow infinity Tees

                                                              Line flow flanged 02

                                                              180deg return bends Line flow threaded 09

                                                              Flanged 02 Branch flow flanged 10

                                                              Threaded 15 Branch flow threaded 20

                                                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                              Square Connection 05 Square Connection 10

                                                              Rounded Connection 02 Rounded Connection 10

                                                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                              Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                              entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                              One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                              entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                              P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                              to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                              the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                              and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                              pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                              result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                              be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                              lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                              LMNOLMNOengcom httpwwwlmnoengcom

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                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                              bull

                                                              Trapezoidal Open Channel Design Calculation

                                                              Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                              Froude number Manning coefficient channel slope

                                                              To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                              Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                              Register to enable Calculate button

                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                              Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                              IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                              beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                              The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                              In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                              Variables [] indicates dimensions To calculation

                                                              A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                              divided by vertical distance

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                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                              Oslash = Angle formed by S

                                                              Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                              Material Manning n Material Manning n

                                                              Natural Streams Excavated Earth Channels

                                                              Clean and Straight 0030 Clean 0022

                                                              Major Rivers 0035 Gravelly 0025

                                                              Sluggish with Deep Pools 0040 Weedy 0030

                                                              Stony Cobbles 0035

                                                              Metals Floodplains

                                                              Brass 0011 Pasture Farmland 0035

                                                              Cast Iron 0013 Light Brush 0050

                                                              Smooth Steel 0012 Heavy Brush 0075

                                                              Corrugated Metal 0022 Trees 015

                                                              Non-Metals

                                                              Glass 0010 Finished Concrete 0012

                                                              Clay Tile 0014 Unfinished Concrete 0014

                                                              Brickwork 0015 Gravel 0029

                                                              Asphalt 0016 Earth 0025

                                                              Masonry 0025 Planed Wood 0012

                                                              Unplaned Wood 0013

                                                              Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                              Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                              Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                              Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                              The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                              cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                              simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                              The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                              References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                              a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                              c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                              e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                              Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                              French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                              d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                              Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                              b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                              7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                              Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                              Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                              View the version 40 New Features List

                                                              Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                              AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                              components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                              From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                              View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                              Learn More About AFT Impulse 40

                                                              Details Views Brochure Demo

                                                              copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                              • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                • Local Disk
                                                                  • Circular Culvert Design Calculations Software Equations
                                                                      • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                                                          • Culvert Design Inlet and Outlet Control
                                                                              • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                • Local Disk
                                                                                  • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                        • Local Disk
                                                                                          • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                              • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                  • Gradually Varied Flow Calculation Backwater profile
                                                                                                      • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                        • Local Disk
                                                                                                          • Hydraulic Jump Calculation
                                                                                                              • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                • Local Disk
                                                                                                                  • Manning Equation
                                                                                                                      • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                          • Non-Circular Open Channel Geometry
                                                                                                                              • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                  • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                          • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                  • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                      • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                                          • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                              • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                                  • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                Equations and Methodology Back to CalculationThe pipe network calculation uses the steady state energy equation Darcy Weisbach or Hazen Williams friction losses and the Hardy Cross method to determine the flowrate in each pipe loss in each pipe and node pressures Minor losses (due to valves pipe bends etc) can be accounted for by using the equivalent length of pipe method

                                                                Hardy Cross Method (Cross 1936 Viessman and Hammer 1993)The Hardy Cross method is also known as the single path adjustment method and is a relaxation method The flowrate in each pipe is adjusted iteratively until all equations are satisfied The method is based on two primary physical laws

                                                                1 The sum of pipe flows into and out of a node equals the flow entering or leaving the system through the node2 Hydraulic head (ie elevation head + pressure head Z+PS) is single-valued This means that the hydraulic head at a node is the same whether it is computed from upstream or downstream directions

                                                                Pipe flows are adjusted iteratively using the following equation

                                                                until the change in flow in each pipe is less than the convergence criterian=20 for Darcy Weisbach losses or 185 for Hazen Williams losses

                                                                Friction Losses HOur calculation gives you a choice of computing friction losses H using the Darcy-Weisbach (DW) or the Hazen-Williams (HW) method The DW method can be used for any liquid or gas while the HW method can only be used for water at temperatures typical of municipal water supply systems HW losses can be selected with the menu that says Roughness e (m) The following equations are used

                                                                Hazen Williams equation (Mays 1999 Streeter et al 1998 Viessman and Hammer 1993) where k=085 for meter and seconds units or 1318 for feet and seconds units

                                                                Darcy Weisbach equation (Mays 1999 Munson et al 1998 Streeter et al 1998)

                                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (2 of 6)12112007 40747 PM

                                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                                Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                                Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                                Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                                Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                                The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                                ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                                1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                                2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                                Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                                Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                                Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                                A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                                n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                                References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                                Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                                fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                bull

                                                                Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                                Weisbach - Moody friction losses)

                                                                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                                Parabolic shaped pump curve is formed from the two points

                                                                ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                                curve Hazen-Williams with pump curve

                                                                Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                                Register to enable Calculate button

                                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                                IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                                A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                                For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                                (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                calculation will look like

                                                                The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                defined for liquids

                                                                Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                hf = Major losses for entire pipe [L] Also known as friction losses

                                                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                hm = Minor losses for entire pipe [L]

                                                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                Fitting K Fitting K

                                                                Valves Elbows

                                                                Globe fully open 10 Regular 90deg flanged 03

                                                                Angle fully open 2 Regular 90deg threaded 15

                                                                Gate fully open 015 Long radius 90deg flanged 02

                                                                Gate 14 closed 026 Long radius 90deg threaded 07

                                                                Gate 12 closed 21 Long radius 45deg threaded 02

                                                                Gate 34 closed 17 Regular 45deg threaded 04

                                                                Swing check forward flow 2

                                                                Swing check backward flow infinity Tees

                                                                Line flow flanged 02

                                                                180deg return bends Line flow threaded 09

                                                                Flanged 02 Branch flow flanged 10

                                                                Threaded 15 Branch flow threaded 20

                                                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                Square Connection 05 Square Connection 10

                                                                Rounded Connection 02 Rounded Connection 10

                                                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                Other messagesK must be gt=1 If Q known Solve for D and V

                                                                3=0 then K must be gt 1 in order to solve

                                                                Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                bull

                                                                Circular Pressurized Water Pipes with Pump Curve

                                                                (Hazen Williams)

                                                                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                curve Darcy-Weisbach with pump curve

                                                                Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                Register to enable Calculate button

                                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                Equations and Methodology Back to Calculations

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                calculation will look like

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                Variables Units L=length P=pressure T=time Back to Calculations

                                                                A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                hf = Major losses for entire pipe [L]

                                                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                hm = Minor losses for entire pipe [L]

                                                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (4 of 8)12112007 40851 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                Material C Material C

                                                                Asbestos Cement 140 Copper 130-140

                                                                Brass 130-140 Galvanized iron 120

                                                                Brick sewer 100 Glass 140

                                                                Cast-Iron Lead 130-140

                                                                New unlined 130 Plastic 140-150

                                                                10 yr old 107-113 Steel

                                                                20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                30 yr old 75-90 New unlined 140-150

                                                                40 yr old 64-83 Riveted 110

                                                                ConcreteConcrete-lined

                                                                Steel forms 140 Tin 130

                                                                Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                Centrifugally spun 135 Wood stave (avg condition) 120

                                                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                Fitting K Fitting K

                                                                Valves Elbows

                                                                Globe fully open 10 Regular 90deg flanged 03

                                                                Angle fully open 2 Regular 90deg threaded 15

                                                                Gate fully open 015 Long radius 90deg flanged 02

                                                                Gate 14 closed 026 Long radius 90deg threaded 07

                                                                Gate 12 closed 21 Long radius 45deg threaded 02

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                Gate 34 closed 17 Regular 45deg threaded 04

                                                                Swing check forward flow 2

                                                                Swing check backward flow infinity Tees

                                                                Line flow flanged 02

                                                                180deg return bends Line flow threaded 09

                                                                Flanged 02 Branch flow flanged 10

                                                                Threaded 15 Branch flow threaded 20

                                                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                Square Connection 05 Square Connection 10

                                                                Rounded Connection 02 Rounded Connection 10

                                                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                bull

                                                                Trapezoidal Open Channel Design Calculation

                                                                Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                Froude number Manning coefficient channel slope

                                                                To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

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                                                                Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                Variables [] indicates dimensions To calculation

                                                                A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                divided by vertical distance

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                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                Oslash = Angle formed by S

                                                                Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                Material Manning n Material Manning n

                                                                Natural Streams Excavated Earth Channels

                                                                Clean and Straight 0030 Clean 0022

                                                                Major Rivers 0035 Gravelly 0025

                                                                Sluggish with Deep Pools 0040 Weedy 0030

                                                                Stony Cobbles 0035

                                                                Metals Floodplains

                                                                Brass 0011 Pasture Farmland 0035

                                                                Cast Iron 0013 Light Brush 0050

                                                                Smooth Steel 0012 Heavy Brush 0075

                                                                Corrugated Metal 0022 Trees 015

                                                                Non-Metals

                                                                Glass 0010 Finished Concrete 0012

                                                                Clay Tile 0014 Unfinished Concrete 0014

                                                                Brickwork 0015 Gravel 0029

                                                                Asphalt 0016 Earth 0025

                                                                Masonry 0025 Planed Wood 0012

                                                                Unplaned Wood 0013

                                                                Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                                Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                View the version 40 New Features List

                                                                Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                Learn More About AFT Impulse 40

                                                                Details Views Brochure Demo

                                                                copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                                                    • Circular Culvert Design Calculations Software Equations
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                                                                            • Culvert Design Inlet and Outlet Control
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                                                                                    • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                                            • Hydraulic Jump Calculation
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                                                                                                                    • Manning Equation
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                                                                                                                            • Non-Circular Open Channel Geometry
                                                                                                                                • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                    • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                        • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                            • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                                    • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                            • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
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                                                                                                                                                                    • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                  where log is base 10 logarithm and ln is natural logarithm Variable definitions

                                                                  Pressure computationAfter computing flowrate Q in each pipe and loss H in each pipe and using the input node elevations Z and known pressure at one node pressure P at each node is computed around the network

                                                                  Pj = S(Zi - Zj - Hpipe) + Pi where node j is down-gradient from node i S = fluid weight density [FL3]

                                                                  Minor LossesMinor losses such as pipe elbows bends and valves may be included by using the equivalent length of pipe method (Mays 1999) Equivalent length (Leq) may be computed using the following calculator which uses the formula Leq=KDf f is the

                                                                  Darcy-Weisbach friction factor for the pipe containing the fitting and cannot be known with certainty until after the pipe network program is run However since you need to know f ahead of time a reasonable value to use is f=002 which is the default value We also recommend using f=002 even if you select Hazen-Williams losses in the pipe network calculation K values are from Mays (1999)

                                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                  For example there is a 100-m long 10-cm diameter (inside diameter) pipe with one fully open gate valve and three regular 90o elbows Using the minor loss calculator Leq is 10 m and 125 m for the fully open gate valve and each elbow respectively

                                                                  The pipe length you should enter into the pipe network calculator is 100 + 10 + 3(125) = 10475 m The calculator allows a variety of units such as m cm inch and ft for diameter and m km ft and miles for equivalent length If a fitting is not listed select User enters K and enter the K value for the fitting

                                                                  ApplicationsThe pipe network calculation has many applications Two examples will be provided

                                                                  1 Municipal water supply system A water tower is located at node D The other nodes could represent industries or homes Enter the water withdrawals at all the nodes as negative numbers then enter the inflow to the network from the water tower at node D as a positive number equal to the sum of the withdrawals from the other nodes Usually cities require a certain minimum pressure everywhere in the system often 40 psi Use the drop-down menu to select the node that you expect will have the lowest pressure - possibly the node furthest from D or the one at the highest elevation well use node I Enter the pressure at node I as 40 psi Enter all the pipe lengths diameters and node elevations Then click Calculate You can use your right and left arrow keys to scroll to the left and right to see the velocity in each pipe Typically you want pipe velocities to be around 2 fts If you are designing a system (as opposed to analyzing a system that is already in place) vary the pipe diameters until the pipe velocities are reasonable and pressure at node D is as low as possible to minimize the height of the water tower There will be a trade-off between pressure at D and pipe diameters Smaller diameter pipes will save money on

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                                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                  pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                                  2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                                  Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                                  Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                                  Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                                  A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                                  n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                                                  fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                  Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                  Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                                  References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

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                                                                  Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                  Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  bull

                                                                  Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                                  Weisbach - Moody friction losses)

                                                                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                  (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                                  Parabolic shaped pump curve is formed from the two points

                                                                  ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                                  curve Hazen-Williams with pump curve

                                                                  Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                                  Register to enable Calculate button

                                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                  Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                                  IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                                  A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                                  For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                                  (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

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                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                  Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                  fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                  calculation will look like

                                                                  The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                  Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                  Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                  is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                  defined for liquids

                                                                  Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                  Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                  A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                  hf = Major losses for entire pipe [L] Also known as friction losses

                                                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                  hm = Minor losses for entire pipe [L]

                                                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                  K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                  for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                  P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                  location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                  zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                  this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                  v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                  Fitting K Fitting K

                                                                  Valves Elbows

                                                                  Globe fully open 10 Regular 90deg flanged 03

                                                                  Angle fully open 2 Regular 90deg threaded 15

                                                                  Gate fully open 015 Long radius 90deg flanged 02

                                                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                                                  Gate 12 closed 21 Long radius 45deg threaded 02

                                                                  Gate 34 closed 17 Regular 45deg threaded 04

                                                                  Swing check forward flow 2

                                                                  Swing check backward flow infinity Tees

                                                                  Line flow flanged 02

                                                                  180deg return bends Line flow threaded 09

                                                                  Flanged 02 Branch flow flanged 10

                                                                  Threaded 15 Branch flow threaded 20

                                                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  Square Connection 05 Square Connection 10

                                                                  Rounded Connection 02 Rounded Connection 10

                                                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                  Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                  The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                  Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                  the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                  Other messagesK must be gt=1 If Q known Solve for D and V

                                                                  3=0 then K must be gt 1 in order to solve

                                                                  Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                  reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                  Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                  Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                  References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                  Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                  Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                  Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                  Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                  White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                                  Circular Pressurized Water Pipes with Pump Curve

                                                                  (Hazen Williams)

                                                                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                  (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                  temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                  ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                  curve Darcy-Weisbach with pump curve

                                                                  Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

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                                                                  Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                  IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                  function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                  manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                  Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                  Equations and Methodology Back to Calculations

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                  The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                  calculation will look like

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                  All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                  Variables Units L=length P=pressure T=time Back to Calculations

                                                                  A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                  g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                  hf = Major losses for entire pipe [L]

                                                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                  hm = Minor losses for entire pipe [L]

                                                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                  k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                  L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                  different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                  program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                  location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                  zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                  this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                  Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                  available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                  and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                  curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                  Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                  Material C Material C

                                                                  Asbestos Cement 140 Copper 130-140

                                                                  Brass 130-140 Galvanized iron 120

                                                                  Brick sewer 100 Glass 140

                                                                  Cast-Iron Lead 130-140

                                                                  New unlined 130 Plastic 140-150

                                                                  10 yr old 107-113 Steel

                                                                  20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                  30 yr old 75-90 New unlined 140-150

                                                                  40 yr old 64-83 Riveted 110

                                                                  ConcreteConcrete-lined

                                                                  Steel forms 140 Tin 130

                                                                  Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                  Centrifugally spun 135 Wood stave (avg condition) 120

                                                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                  Fitting K Fitting K

                                                                  Valves Elbows

                                                                  Globe fully open 10 Regular 90deg flanged 03

                                                                  Angle fully open 2 Regular 90deg threaded 15

                                                                  Gate fully open 015 Long radius 90deg flanged 02

                                                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                                                  Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                  Gate 34 closed 17 Regular 45deg threaded 04

                                                                  Swing check forward flow 2

                                                                  Swing check backward flow infinity Tees

                                                                  Line flow flanged 02

                                                                  180deg return bends Line flow threaded 09

                                                                  Flanged 02 Branch flow flanged 10

                                                                  Threaded 15 Branch flow threaded 20

                                                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                  Square Connection 05 Square Connection 10

                                                                  Rounded Connection 02 Rounded Connection 10

                                                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                  Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                  entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                  One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                  entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                  P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                  to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                  the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                  and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                  pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                  result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                  be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                  lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                                  Trapezoidal Open Channel Design Calculation

                                                                  Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                  Froude number Manning coefficient channel slope

                                                                  To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                  Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                                                  Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                  IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                  beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                  The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                  In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                  Variables [] indicates dimensions To calculation

                                                                  A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                  divided by vertical distance

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                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                  Oslash = Angle formed by S

                                                                  Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                  Material Manning n Material Manning n

                                                                  Natural Streams Excavated Earth Channels

                                                                  Clean and Straight 0030 Clean 0022

                                                                  Major Rivers 0035 Gravelly 0025

                                                                  Sluggish with Deep Pools 0040 Weedy 0030

                                                                  Stony Cobbles 0035

                                                                  Metals Floodplains

                                                                  Brass 0011 Pasture Farmland 0035

                                                                  Cast Iron 0013 Light Brush 0050

                                                                  Smooth Steel 0012 Heavy Brush 0075

                                                                  Corrugated Metal 0022 Trees 015

                                                                  Non-Metals

                                                                  Glass 0010 Finished Concrete 0012

                                                                  Clay Tile 0014 Unfinished Concrete 0014

                                                                  Brickwork 0015 Gravel 0029

                                                                  Asphalt 0016 Earth 0025

                                                                  Masonry 0025 Planed Wood 0012

                                                                  Unplaned Wood 0013

                                                                  Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                  Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                  Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                  Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                  The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                  cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                  simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                  The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                  References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                  a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                  c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                  e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                  Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                  French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                  d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                  Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                  b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                  7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                  Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                  Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                  View the version 40 New Features List

                                                                  Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                  AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                  fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                  components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                  From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                  View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                  Learn More About AFT Impulse 40

                                                                  Details Views Brochure Demo

                                                                  copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                  fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                    • Local Disk
                                                                      • Circular Culvert Design Calculations Software Equations
                                                                          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                            • Local Disk
                                                                              • Culvert Design Inlet and Outlet Control
                                                                                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                    • Local Disk
                                                                                      • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                          • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                              • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                  • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                      • Gradually Varied Flow Calculation Backwater profile
                                                                                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                            • Local Disk
                                                                                                              • Hydraulic Jump Calculation
                                                                                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                    • Local Disk
                                                                                                                      • Manning Equation
                                                                                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                            • Local Disk
                                                                                                                              • Non-Circular Open Channel Geometry
                                                                                                                                  • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                    • Local Disk
                                                                                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                            • Local Disk
                                                                                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                            • Local Disk
                                                                                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                    • Local Disk
                                                                                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                    pipes but will require a taller water tower The water tower height is proportional to the pressure at D according to h=PS where P is the pressure at D S is the weight density of the water and h is the water tower height required A more detailed example

                                                                    2 Manifold A manifold has multiple inflows at various positions along the same pipeline and one outflow Let node I be the outflow and use all other nodes A-H as inflow locations so flow is from node A through pipes 1 2 5 7 6 8 11 and 12 and out node I Enter the diameters and lengths of these pipes and the desired inflows at nodes A-H Enter the outflow at node I as a positive number equal to the sum of the inflows at nodes A-H Enter the diameters of pipes 3 4 9 and 10 as 00 since they are non-existent pipes Enter the elevations of all nodes For a horizontal pipe set all the elevations to the same value or just to 00 to keep it simple From the drop-down menu select the node where you know the pressure and enter its pressure Clicking Calculate will give the flowrate in all pipes and the pressure at all the nodes

                                                                    Built-in fluid and material propertiesThe user may manually enter fluid density and viscosity or select one of the common liquids or gases from the drop-down menu Density and viscosity for the built-in fluids were obtained from Munson et al (1998) Likewise the user may manually enter material roughness or Hazen-Williams C or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from Munson et al (1998) Streeter et al (1998) and Mays (1999)

                                                                    Unitsbblsday=barrelsday cfm=ft3min cfs=ft3s cm=centimeter cP=centipoise cSt=centistoke in=inch in H2O=inch water at 60F in Hg=inch mercury at 60F ft=foot g=gram gpd=gallon (US)day gph=gallon (US)hr gpm=gallon (US)min hr=hour kg=kilogram km=kilometer lb=pound lb(f)=pound (force) m=meter mbar=millibar mm=millimeter mm H2O=mm water at 4C min=minute N=Newton psi=lb(f)in2 s=second

                                                                    Variables [] indicates units F=force L=length P=pressure T=time Back to Calculation

                                                                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used internally

                                                                    A = Pipe area [L2]C = Hazen Williams coefficient Selectable as last item in drop-down menu saying Roughness eD = Pipe diameter [L]e = Pipe roughness [L] All pipes must have the same roughnessf = Moody friction factor used in Darcy Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2H = Head losses in pipe [L] Can also be expressed in pressure units [P]k = Constant in Hazen Williams equation for computing HK = Minor loss coefficientL = Pipe length [L]Leq = Equivalent length of pipe for minor losses [L]

                                                                    n = Constant used in Hardy Cross equationP = Node pressure [P] Can also be expressed in length units [L]Q = Flowrate through pipe or into or out of node [L3T] Also known as discharge or capacityRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3

                                                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (4 of 6)12112007 40747 PM

                                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                    Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                    Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                                    References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                                    Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                    Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                    LMNOLMNOengcom httpwwwlmnoengcom

                                                                    fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    bull

                                                                    Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                                    Weisbach - Moody friction losses)

                                                                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                    (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                                    Parabolic shaped pump curve is formed from the two points

                                                                    ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                                    curve Hazen-Williams with pump curve

                                                                    Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                                    Register to enable Calculate button

                                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                    Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                                    IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                                    A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                                    For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                                    (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                    Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                    calculation will look like

                                                                    The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                    Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                    Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                    is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                    defined for liquids

                                                                    Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                    Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                    A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                    hf = Major losses for entire pipe [L] Also known as friction losses

                                                                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                    hm = Minor losses for entire pipe [L]

                                                                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                    K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                    for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                    P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                    location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                    zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                    this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                    v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                    Fitting K Fitting K

                                                                    Valves Elbows

                                                                    Globe fully open 10 Regular 90deg flanged 03

                                                                    Angle fully open 2 Regular 90deg threaded 15

                                                                    Gate fully open 015 Long radius 90deg flanged 02

                                                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                                                    Gate 34 closed 17 Regular 45deg threaded 04

                                                                    Swing check forward flow 2

                                                                    Swing check backward flow infinity Tees

                                                                    Line flow flanged 02

                                                                    180deg return bends Line flow threaded 09

                                                                    Flanged 02 Branch flow flanged 10

                                                                    Threaded 15 Branch flow threaded 20

                                                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    Square Connection 05 Square Connection 10

                                                                    Rounded Connection 02 Rounded Connection 10

                                                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                    Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                    The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                    Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                    the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                    Other messagesK must be gt=1 If Q known Solve for D and V

                                                                    3=0 then K must be gt 1 in order to solve

                                                                    Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                    reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                    Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                    Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                    References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                    Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                    Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                    Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                    Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                    White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                    LMNOLMNOengcom httpwwwlmnoengcom

                                                                    fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                                    Circular Pressurized Water Pipes with Pump Curve

                                                                    (Hazen Williams)

                                                                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                    (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                    ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                    curve Darcy-Weisbach with pump curve

                                                                    Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                    Register to enable Calculate button

                                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                    Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                    IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                    function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                    manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                    Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                    Equations and Methodology Back to Calculations

                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                    The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                    calculation will look like

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                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                    Variables Units L=length P=pressure T=time Back to Calculations

                                                                    A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                    g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                    hf = Major losses for entire pipe [L]

                                                                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                    hm = Minor losses for entire pipe [L]

                                                                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                    k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                    L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                    different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                    program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                    location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                    zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                    this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                    Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                    available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                    and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                    curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                    Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                    Material C Material C

                                                                    Asbestos Cement 140 Copper 130-140

                                                                    Brass 130-140 Galvanized iron 120

                                                                    Brick sewer 100 Glass 140

                                                                    Cast-Iron Lead 130-140

                                                                    New unlined 130 Plastic 140-150

                                                                    10 yr old 107-113 Steel

                                                                    20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                    30 yr old 75-90 New unlined 140-150

                                                                    40 yr old 64-83 Riveted 110

                                                                    ConcreteConcrete-lined

                                                                    Steel forms 140 Tin 130

                                                                    Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                    Centrifugally spun 135 Wood stave (avg condition) 120

                                                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                    Fitting K Fitting K

                                                                    Valves Elbows

                                                                    Globe fully open 10 Regular 90deg flanged 03

                                                                    Angle fully open 2 Regular 90deg threaded 15

                                                                    Gate fully open 015 Long radius 90deg flanged 02

                                                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                    Gate 34 closed 17 Regular 45deg threaded 04

                                                                    Swing check forward flow 2

                                                                    Swing check backward flow infinity Tees

                                                                    Line flow flanged 02

                                                                    180deg return bends Line flow threaded 09

                                                                    Flanged 02 Branch flow flanged 10

                                                                    Threaded 15 Branch flow threaded 20

                                                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                    Square Connection 05 Square Connection 10

                                                                    Rounded Connection 02 Rounded Connection 10

                                                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                    Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                    entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                    One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                    entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                    P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                    to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                    the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                    and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                    pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                    result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                    be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                    lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                    LMNOLMNOengcom httpwwwlmnoengcom

                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                                    Trapezoidal Open Channel Design Calculation

                                                                    Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                    Froude number Manning coefficient channel slope

                                                                    To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                    Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                    Register to enable Calculate button

                                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                    Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                    IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                    beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                    The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                    Variables [] indicates dimensions To calculation

                                                                    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                    divided by vertical distance

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                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                    Oslash = Angle formed by S

                                                                    Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                    Material Manning n Material Manning n

                                                                    Natural Streams Excavated Earth Channels

                                                                    Clean and Straight 0030 Clean 0022

                                                                    Major Rivers 0035 Gravelly 0025

                                                                    Sluggish with Deep Pools 0040 Weedy 0030

                                                                    Stony Cobbles 0035

                                                                    Metals Floodplains

                                                                    Brass 0011 Pasture Farmland 0035

                                                                    Cast Iron 0013 Light Brush 0050

                                                                    Smooth Steel 0012 Heavy Brush 0075

                                                                    Corrugated Metal 0022 Trees 015

                                                                    Non-Metals

                                                                    Glass 0010 Finished Concrete 0012

                                                                    Clay Tile 0014 Unfinished Concrete 0014

                                                                    Brickwork 0015 Gravel 0029

                                                                    Asphalt 0016 Earth 0025

                                                                    Masonry 0025 Planed Wood 0012

                                                                    Unplaned Wood 0013

                                                                    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                    Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                    The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                    cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                    simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                    The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                    References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                    a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                    Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                    French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                    Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                    7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                                    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                    View the version 40 New Features List

                                                                    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                    Learn More About AFT Impulse 40

                                                                    Details Views Brochure Demo

                                                                    copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                                                        • Circular Culvert Design Calculations Software Equations
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                                                                                • Culvert Design Inlet and Outlet Control
                                                                                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                                        • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                            • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                                • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                    • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                        • Gradually Varied Flow Calculation Backwater profile
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                                                                                                                • Hydraulic Jump Calculation
                                                                                                                    • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                                        • Manning Equation
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                                                                                                                                • Non-Circular Open Channel Geometry
                                                                                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                      Note that S=(mass density)(g)V = Velocity in pipe [LT]Z = Elevation of node [L]Z+PS = Hydraulic head [L] Also known as piezometric head Can also be expressed in pressure units [P]v = Kinematic viscosity of fluid [L2T] Greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                      Error Messages in Pipe Network calculation Back to CalculationNode Qs must sum to 0 Check the node flowrates that you entered Total flow into pipe network must equal total flow out of pipe networkTotal inflow must be gt0 Check that you have positive flow into the system You have entered all node flows as 00 or negativeNode i must have Q=0 Node i is completely surrounded by pipes having diameters less than 0001 m which is the criteria the program uses for treating pipes as being non-existent You cannot have flow in or out of a node that is surrounded by non-existent pipes|Q| must be lt 1e9 m3s Node flows cannot exceed 109 m3s | | is absolute valueP at isolated node Be sure that the P known at node x drop-down menu indicates a node that is surrounded by at least one existing pipe (ie a pipe having a diameter greater than 0001 m) If you dont know the pressure anywhere in your system just enter 00 for the pressure All the other node pressures will be computed relative to the pressure you enterDensity must be gt 0 Density too high Viscosity must be gt 0 Viscosity too high These messages can only occur if Another fluid is selected from the fluid drop-down menu Be sure the density and viscosity you enter are greater than zero but less than 1010 kgm3 and 1010 m2s respectivelyD must be lt 1e6 m Individual pipe diameters cannot exceed 106 mL must be lt 1e7 m Individual pipe lengths cannot exceed 107 m|Z| must be lt 1e20 |P| must be lt 1e20 m The absolute value of each node elevation and pressure that are input cannot exceed 1020 mNeed Water (20C) if H-W If Hazen-Williams C is selected from the Roughness drop-down menu you must also select Water 20C (68F) from the fluid drop-down menu The Hazen-Williams method for head losses is only valid for water at typical city water supply temperatures such as 20CC out of range e out of range These messages can only occur if you selected Another material from the pipe material drop-down menu Valid ranges are 0ltClt1000 and 0 lt= e lt 100 m Normally C will not exceed 150 and e will not exceed 0001 m but we allow high ranges for those who like to experimentPipe i eD out of range See the equations above for Friction loss computation using Darcy-Weisbach eD cannot exceed 005 unless Reynolds number is less than 4000 Also eD cannot be 00 (ie e cannot be 00) if Reynolds number is greater than 108Unusual input If you experiment with the calculation long enough you may enter some very unusual input combinations Some situations are physically not possible but the calculation will continue iterating to compute the pipe flows and losses After 5000 iterations (a few seconds of real time) the program will stop running and give you this error message so you can check your input and enter more realistic numbers The program has been designed so that it will not lock upOther things If the calculation doesnt seem to run when you click Calculate check your inputs If you accidentally entered two decimal points or a letter in an input field then it wont run and wont give an error message

                                                                      References Back to CalculationCross Hardy Analysis of flow in networks of conduits or conductors University of Illinois Bulletin No 286 November 1936

                                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (5 of 6)12112007 40747 PM

                                                                      Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                      Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                      LMNOLMNOengcom httpwwwlmnoengcom

                                                                      fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      bull

                                                                      Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                                      Weisbach - Moody friction losses)

                                                                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                      (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                                      Parabolic shaped pump curve is formed from the two points

                                                                      ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                                      curve Hazen-Williams with pump curve

                                                                      Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                                      Register to enable Calculate button

                                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                      Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                                      IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                                      A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                                      For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                                      (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                      Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                      calculation will look like

                                                                      The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                      Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                      Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                      is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                      defined for liquids

                                                                      Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                      Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                      A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                      hf = Major losses for entire pipe [L] Also known as friction losses

                                                                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                      hm = Minor losses for entire pipe [L]

                                                                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                      K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                      for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                      P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                      location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                      zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                      this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                      v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                      Fitting K Fitting K

                                                                      Valves Elbows

                                                                      Globe fully open 10 Regular 90deg flanged 03

                                                                      Angle fully open 2 Regular 90deg threaded 15

                                                                      Gate fully open 015 Long radius 90deg flanged 02

                                                                      Gate 14 closed 026 Long radius 90deg threaded 07

                                                                      Gate 12 closed 21 Long radius 45deg threaded 02

                                                                      Gate 34 closed 17 Regular 45deg threaded 04

                                                                      Swing check forward flow 2

                                                                      Swing check backward flow infinity Tees

                                                                      Line flow flanged 02

                                                                      180deg return bends Line flow threaded 09

                                                                      Flanged 02 Branch flow flanged 10

                                                                      Threaded 15 Branch flow threaded 20

                                                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      Square Connection 05 Square Connection 10

                                                                      Rounded Connection 02 Rounded Connection 10

                                                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                      Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                      The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                      Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                      the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                      Other messagesK must be gt=1 If Q known Solve for D and V

                                                                      3=0 then K must be gt 1 in order to solve

                                                                      Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                      reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                      Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                      Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                      References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                      Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                      Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                      Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                      Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                      White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                      LMNOLMNOengcom httpwwwlmnoengcom

                                                                      fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      bull

                                                                      Circular Pressurized Water Pipes with Pump Curve

                                                                      (Hazen Williams)

                                                                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                      (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                      ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                      curve Darcy-Weisbach with pump curve

                                                                      Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                      Register to enable Calculate button

                                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                      Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                      IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                      function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                      manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                      Equations and Methodology Back to Calculations

                                                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                      calculation will look like

                                                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                      Variables Units L=length P=pressure T=time Back to Calculations

                                                                      A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                      g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                      hf = Major losses for entire pipe [L]

                                                                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                      hm = Minor losses for entire pipe [L]

                                                                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                      k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                      L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                      program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                      location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                      zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                      this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                      Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                      available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                      and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                      Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                      Material C Material C

                                                                      Asbestos Cement 140 Copper 130-140

                                                                      Brass 130-140 Galvanized iron 120

                                                                      Brick sewer 100 Glass 140

                                                                      Cast-Iron Lead 130-140

                                                                      New unlined 130 Plastic 140-150

                                                                      10 yr old 107-113 Steel

                                                                      20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                      30 yr old 75-90 New unlined 140-150

                                                                      40 yr old 64-83 Riveted 110

                                                                      ConcreteConcrete-lined

                                                                      Steel forms 140 Tin 130

                                                                      Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                      Centrifugally spun 135 Wood stave (avg condition) 120

                                                                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                      Fitting K Fitting K

                                                                      Valves Elbows

                                                                      Globe fully open 10 Regular 90deg flanged 03

                                                                      Angle fully open 2 Regular 90deg threaded 15

                                                                      Gate fully open 015 Long radius 90deg flanged 02

                                                                      Gate 14 closed 026 Long radius 90deg threaded 07

                                                                      Gate 12 closed 21 Long radius 45deg threaded 02

                                                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      Gate 34 closed 17 Regular 45deg threaded 04

                                                                      Swing check forward flow 2

                                                                      Swing check backward flow infinity Tees

                                                                      Line flow flanged 02

                                                                      180deg return bends Line flow threaded 09

                                                                      Flanged 02 Branch flow flanged 10

                                                                      Threaded 15 Branch flow threaded 20

                                                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                      Square Connection 05 Square Connection 10

                                                                      Rounded Connection 02 Rounded Connection 10

                                                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                      Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                      entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                      One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                      entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                      P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                      to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                      the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                      and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                      pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                      result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                      be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                      lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                      LMNOLMNOengcom httpwwwlmnoengcom

                                                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                      bull

                                                                      Trapezoidal Open Channel Design Calculation

                                                                      Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                      Froude number Manning coefficient channel slope

                                                                      To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                      Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                      Register to enable Calculate button

                                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                      Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                      IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                      beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                      The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                      In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                      Variables [] indicates dimensions To calculation

                                                                      A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                      divided by vertical distance

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                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                      Oslash = Angle formed by S

                                                                      Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                      Material Manning n Material Manning n

                                                                      Natural Streams Excavated Earth Channels

                                                                      Clean and Straight 0030 Clean 0022

                                                                      Major Rivers 0035 Gravelly 0025

                                                                      Sluggish with Deep Pools 0040 Weedy 0030

                                                                      Stony Cobbles 0035

                                                                      Metals Floodplains

                                                                      Brass 0011 Pasture Farmland 0035

                                                                      Cast Iron 0013 Light Brush 0050

                                                                      Smooth Steel 0012 Heavy Brush 0075

                                                                      Corrugated Metal 0022 Trees 015

                                                                      Non-Metals

                                                                      Glass 0010 Finished Concrete 0012

                                                                      Clay Tile 0014 Unfinished Concrete 0014

                                                                      Brickwork 0015 Gravel 0029

                                                                      Asphalt 0016 Earth 0025

                                                                      Masonry 0025 Planed Wood 0012

                                                                      Unplaned Wood 0013

                                                                      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                      Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                      The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                      cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                      simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                      The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                      References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                      a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                      Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                      French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                      Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                      7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                      Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                      Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                      View the version 40 New Features List

                                                                      Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                      AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                      From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                      View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                      Learn More About AFT Impulse 40

                                                                      Details Views Brochure Demo

                                                                      copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                        • Local Disk
                                                                          • Circular Culvert Design Calculations Software Equations
                                                                              • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                • Local Disk
                                                                                  • Culvert Design Inlet and Outlet Control
                                                                                      • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                        • Local Disk
                                                                                          • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                              • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                • Local Disk
                                                                                                  • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                      • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                        • Local Disk
                                                                                                          • Gradually Varied Flow Calculation Backwater profile
                                                                                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                • Local Disk
                                                                                                                  • Hydraulic Jump Calculation
                                                                                                                      • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                        • Local Disk
                                                                                                                          • Manning Equation
                                                                                                                              • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                • Local Disk
                                                                                                                                  • Non-Circular Open Channel Geometry
                                                                                                                                      • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                        • Local Disk
                                                                                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                • Local Disk
                                                                                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                        • Local Disk
                                                                                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                              • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                • Local Disk
                                                                                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                        • Local Disk
                                                                                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                        Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses

                                                                        Viessman W and M J Hammer 1993 Water Supply and Pollution Control HarperCollins College Publishers 5ed

                                                                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                        LMNOLMNOengcom httpwwwlmnoengcom

                                                                        fileE|engineeringhydraulicsPipe20Network20Carcy20Weisbach20or20Hazen20Williams20losseshtm (6 of 6)12112007 40747 PM

                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        bull

                                                                        Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                                        Weisbach - Moody friction losses)

                                                                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                        (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                                        Parabolic shaped pump curve is formed from the two points

                                                                        ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                                        curve Hazen-Williams with pump curve

                                                                        Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                                        Register to enable Calculate button

                                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                        Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                                        IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                                        A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                                        For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                                        (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                        Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                        calculation will look like

                                                                        The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                        Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                        Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                        is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                        defined for liquids

                                                                        Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                        Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                                        fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                        A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                        hf = Major losses for entire pipe [L] Also known as friction losses

                                                                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                        hm = Minor losses for entire pipe [L]

                                                                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                        K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                        for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                        P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                        location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                        zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                        this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                        v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                        Fitting K Fitting K

                                                                        Valves Elbows

                                                                        Globe fully open 10 Regular 90deg flanged 03

                                                                        Angle fully open 2 Regular 90deg threaded 15

                                                                        Gate fully open 015 Long radius 90deg flanged 02

                                                                        Gate 14 closed 026 Long radius 90deg threaded 07

                                                                        Gate 12 closed 21 Long radius 45deg threaded 02

                                                                        Gate 34 closed 17 Regular 45deg threaded 04

                                                                        Swing check forward flow 2

                                                                        Swing check backward flow infinity Tees

                                                                        Line flow flanged 02

                                                                        180deg return bends Line flow threaded 09

                                                                        Flanged 02 Branch flow flanged 10

                                                                        Threaded 15 Branch flow threaded 20

                                                                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        Square Connection 05 Square Connection 10

                                                                        Rounded Connection 02 Rounded Connection 10

                                                                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                        Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                        The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                        Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                        the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                        Other messagesK must be gt=1 If Q known Solve for D and V

                                                                        3=0 then K must be gt 1 in order to solve

                                                                        Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                        reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                        Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                        Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                        References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                        Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                        Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                        Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                        Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                        White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                                        Circular Pressurized Water Pipes with Pump Curve

                                                                        (Hazen Williams)

                                                                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                        (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                        ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                        curve Darcy-Weisbach with pump curve

                                                                        Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                        Register to enable Calculate button

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                                                                        Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                        IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                        function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                        manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                        Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                        Equations and Methodology Back to Calculations

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                        The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                        calculation will look like

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                        Variables Units L=length P=pressure T=time Back to Calculations

                                                                        A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                        g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                        hf = Major losses for entire pipe [L]

                                                                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                        hm = Minor losses for entire pipe [L]

                                                                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                        k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                        L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                        different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                        program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                        location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                        zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                        this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                        Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                        available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                        and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                        curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                        Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                        Material C Material C

                                                                        Asbestos Cement 140 Copper 130-140

                                                                        Brass 130-140 Galvanized iron 120

                                                                        Brick sewer 100 Glass 140

                                                                        Cast-Iron Lead 130-140

                                                                        New unlined 130 Plastic 140-150

                                                                        10 yr old 107-113 Steel

                                                                        20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                        30 yr old 75-90 New unlined 140-150

                                                                        40 yr old 64-83 Riveted 110

                                                                        ConcreteConcrete-lined

                                                                        Steel forms 140 Tin 130

                                                                        Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                        Centrifugally spun 135 Wood stave (avg condition) 120

                                                                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                        Fitting K Fitting K

                                                                        Valves Elbows

                                                                        Globe fully open 10 Regular 90deg flanged 03

                                                                        Angle fully open 2 Regular 90deg threaded 15

                                                                        Gate fully open 015 Long radius 90deg flanged 02

                                                                        Gate 14 closed 026 Long radius 90deg threaded 07

                                                                        Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                        Gate 34 closed 17 Regular 45deg threaded 04

                                                                        Swing check forward flow 2

                                                                        Swing check backward flow infinity Tees

                                                                        Line flow flanged 02

                                                                        180deg return bends Line flow threaded 09

                                                                        Flanged 02 Branch flow flanged 10

                                                                        Threaded 15 Branch flow threaded 20

                                                                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                        Square Connection 05 Square Connection 10

                                                                        Rounded Connection 02 Rounded Connection 10

                                                                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                        Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                        entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                        One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                        entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                        P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                        to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                        the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                        and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                        pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                        result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                        be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                        lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                                        Trapezoidal Open Channel Design Calculation

                                                                        Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                        Froude number Manning coefficient channel slope

                                                                        To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                        Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                                                        Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                        IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                        beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                        The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                        In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                        Variables [] indicates dimensions To calculation

                                                                        A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                        divided by vertical distance

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                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                        Oslash = Angle formed by S

                                                                        Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                        Material Manning n Material Manning n

                                                                        Natural Streams Excavated Earth Channels

                                                                        Clean and Straight 0030 Clean 0022

                                                                        Major Rivers 0035 Gravelly 0025

                                                                        Sluggish with Deep Pools 0040 Weedy 0030

                                                                        Stony Cobbles 0035

                                                                        Metals Floodplains

                                                                        Brass 0011 Pasture Farmland 0035

                                                                        Cast Iron 0013 Light Brush 0050

                                                                        Smooth Steel 0012 Heavy Brush 0075

                                                                        Corrugated Metal 0022 Trees 015

                                                                        Non-Metals

                                                                        Glass 0010 Finished Concrete 0012

                                                                        Clay Tile 0014 Unfinished Concrete 0014

                                                                        Brickwork 0015 Gravel 0029

                                                                        Asphalt 0016 Earth 0025

                                                                        Masonry 0025 Planed Wood 0012

                                                                        Unplaned Wood 0013

                                                                        Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                        Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                        Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                        Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                        The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                        cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                        simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                        The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                        References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                        a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                        Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                        French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                        Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                        7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                        Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                        Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

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                                                                        Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                        AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                        components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                        From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                        View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

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                                                                        Details Views Brochure Demo

                                                                        copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                        • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                          • Local Disk
                                                                            • Circular Culvert Design Calculations Software Equations
                                                                                • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                                                                    • Culvert Design Inlet and Outlet Control
                                                                                        • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                          • Local Disk
                                                                                            • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                  • Local Disk
                                                                                                    • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                        • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                            • Gradually Varied Flow Calculation Backwater profile
                                                                                                                • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                  • Local Disk
                                                                                                                    • Hydraulic Jump Calculation
                                                                                                                        • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                          • Local Disk
                                                                                                                            • Manning Equation
                                                                                                                                • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                                    • Non-Circular Open Channel Geometry
                                                                                                                                        • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                          • Local Disk
                                                                                                                                            • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                  • Local Disk
                                                                                                                                                    • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                        • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                            • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                  • Local Disk
                                                                                                                                                                    • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                        • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                          • Local Disk
                                                                                                                                                                            • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          bull

                                                                          Circular Pressurized Liquid or Gas Pipe with Pump Curve (Darcy

                                                                          Weisbach - Moody friction losses)

                                                                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                          (using Darcy-Weisbach friction loss ie Moody Diagram) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head

                                                                          Parabolic shaped pump curve is formed from the two points

                                                                          ToOther single pipe calculators Darcy-Weisbach without pump curve Hazen-Williams without pump

                                                                          curve Hazen-Williams with pump curve

                                                                          Multiple pipes Bypass Loop Pipe Network LMNO Engineering home page (more calculations) Unit Conversions Page Trouble printing

                                                                          Register to enable Calculate button

                                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                          Topics Piping Scenarios Equations and Methodology Variables Minor Loss Coefficients Error Messages References

                                                                          IntroductionThis program automatically intersects a system curve with a pump curve to tell you the operating point If you have a pump already installed or want to investigate system performance of a certain pump before purchasing it you can enter two points on its pump curve along with piping system information to determine the actual flowrate through the system Or if you know the flowrate or velocity you can solve for diameter pipe length pressure difference elevation difference or the sum of the minor loss coefficients

                                                                          A pump curve (blower curve for gases) is incorporated into the calculation to simulate systems containing a centrifugal pump or other pump that has a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) for liquids

                                                                          For a pump to properly function the NPSHA must be greater than the NPSH required by the pump

                                                                          (obtained from the pump manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Darcy Weisbach design calculation may be more helpful

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (1 of 8)12112007 40817 PM

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (2 of 8)12112007 40817 PM

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                          Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                          calculation will look like

                                                                          The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                          Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                          Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                          is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                          defined for liquids

                                                                          Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                          Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                          A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                          hf = Major losses for entire pipe [L] Also known as friction losses

                                                                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                          hm = Minor losses for entire pipe [L]

                                                                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                          K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                          for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                          P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                          location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                          zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (5 of 8)12112007 40817 PM

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                          this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                          v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                          Fitting K Fitting K

                                                                          Valves Elbows

                                                                          Globe fully open 10 Regular 90deg flanged 03

                                                                          Angle fully open 2 Regular 90deg threaded 15

                                                                          Gate fully open 015 Long radius 90deg flanged 02

                                                                          Gate 14 closed 026 Long radius 90deg threaded 07

                                                                          Gate 12 closed 21 Long radius 45deg threaded 02

                                                                          Gate 34 closed 17 Regular 45deg threaded 04

                                                                          Swing check forward flow 2

                                                                          Swing check backward flow infinity Tees

                                                                          Line flow flanged 02

                                                                          180deg return bends Line flow threaded 09

                                                                          Flanged 02 Branch flow flanged 10

                                                                          Threaded 15 Branch flow threaded 20

                                                                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (6 of 8)12112007 40817 PM

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          Square Connection 05 Square Connection 10

                                                                          Rounded Connection 02 Rounded Connection 10

                                                                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                          Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                          The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                          Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                          the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                          Other messagesK must be gt=1 If Q known Solve for D and V

                                                                          3=0 then K must be gt 1 in order to solve

                                                                          Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                          reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                          Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                          Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                          References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                          Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                          Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (7 of 8)12112007 40817 PM

                                                                          Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                          Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                          Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                          Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                          White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                          copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                          LMNOLMNOengcom httpwwwlmnoengcom

                                                                          fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (8 of 8)12112007 40817 PM

                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          bull

                                                                          Circular Pressurized Water Pipes with Pump Curve

                                                                          (Hazen Williams)

                                                                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                          (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                          temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                          ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                          curve Darcy-Weisbach with pump curve

                                                                          Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                          Register to enable Calculate button

                                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                          Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                          IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                          function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                          manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

                                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (1 of 8)12112007 40851 PM

                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                          Equations and Methodology Back to Calculations

                                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                          calculation will look like

                                                                          fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                          Variables Units L=length P=pressure T=time Back to Calculations

                                                                          A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                          g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                          hf = Major losses for entire pipe [L]

                                                                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                          hm = Minor losses for entire pipe [L]

                                                                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                          k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                          L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                          program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                          location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                          zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                          this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                          Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                          available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                          and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                          Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                          Material C Material C

                                                                          Asbestos Cement 140 Copper 130-140

                                                                          Brass 130-140 Galvanized iron 120

                                                                          Brick sewer 100 Glass 140

                                                                          Cast-Iron Lead 130-140

                                                                          New unlined 130 Plastic 140-150

                                                                          10 yr old 107-113 Steel

                                                                          20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                          30 yr old 75-90 New unlined 140-150

                                                                          40 yr old 64-83 Riveted 110

                                                                          ConcreteConcrete-lined

                                                                          Steel forms 140 Tin 130

                                                                          Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                          Centrifugally spun 135 Wood stave (avg condition) 120

                                                                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                          Fitting K Fitting K

                                                                          Valves Elbows

                                                                          Globe fully open 10 Regular 90deg flanged 03

                                                                          Angle fully open 2 Regular 90deg threaded 15

                                                                          Gate fully open 015 Long radius 90deg flanged 02

                                                                          Gate 14 closed 026 Long radius 90deg threaded 07

                                                                          Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          Gate 34 closed 17 Regular 45deg threaded 04

                                                                          Swing check forward flow 2

                                                                          Swing check backward flow infinity Tees

                                                                          Line flow flanged 02

                                                                          180deg return bends Line flow threaded 09

                                                                          Flanged 02 Branch flow flanged 10

                                                                          Threaded 15 Branch flow threaded 20

                                                                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                          Square Connection 05 Square Connection 10

                                                                          Rounded Connection 02 Rounded Connection 10

                                                                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                          Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                          entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                          One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                          entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                          P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                          to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                          the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                          and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                          pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                          result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                          be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                          lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                          LMNOLMNOengcom httpwwwlmnoengcom

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                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                          bull

                                                                          Trapezoidal Open Channel Design Calculation

                                                                          Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                          Froude number Manning coefficient channel slope

                                                                          To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                          Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                          Register to enable Calculate button

                                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                          Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                          IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                          beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                          The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                          In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                          Variables [] indicates dimensions To calculation

                                                                          A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                          divided by vertical distance

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                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                          Oslash = Angle formed by S

                                                                          Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                          Material Manning n Material Manning n

                                                                          Natural Streams Excavated Earth Channels

                                                                          Clean and Straight 0030 Clean 0022

                                                                          Major Rivers 0035 Gravelly 0025

                                                                          Sluggish with Deep Pools 0040 Weedy 0030

                                                                          Stony Cobbles 0035

                                                                          Metals Floodplains

                                                                          Brass 0011 Pasture Farmland 0035

                                                                          Cast Iron 0013 Light Brush 0050

                                                                          Smooth Steel 0012 Heavy Brush 0075

                                                                          Corrugated Metal 0022 Trees 015

                                                                          Non-Metals

                                                                          Glass 0010 Finished Concrete 0012

                                                                          Clay Tile 0014 Unfinished Concrete 0014

                                                                          Brickwork 0015 Gravel 0029

                                                                          Asphalt 0016 Earth 0025

                                                                          Masonry 0025 Planed Wood 0012

                                                                          Unplaned Wood 0013

                                                                          Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                          Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                          Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                          Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                          The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                          cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                          simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                          The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                          References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                          a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                          c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                          e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                          Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                          French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                          d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                          Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                          b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                          7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                          Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                          Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                          View the version 40 New Features List

                                                                          Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                          AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                          components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                          From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                          View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                          Learn More About AFT Impulse 40

                                                                          Details Views Brochure Demo

                                                                          copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                          • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                            • Local Disk
                                                                              • Circular Culvert Design Calculations Software Equations
                                                                                  • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                    • Local Disk
                                                                                      • Culvert Design Inlet and Outlet Control
                                                                                          • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                            • Local Disk
                                                                                              • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                  • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                                      • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                          • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                              • Gradually Varied Flow Calculation Backwater profile
                                                                                                                  • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                    • Local Disk
                                                                                                                      • Hydraulic Jump Calculation
                                                                                                                          • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                            • Local Disk
                                                                                                                              • Manning Equation
                                                                                                                                  • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                                      • Non-Circular Open Channel Geometry
                                                                                                                                          • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                            • Local Disk
                                                                                                                                              • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                      • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                              • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                  • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                                                      • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                          • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                            • Local Disk
                                                                                                                                                                              • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

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                                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                            Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                            Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

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                                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                            calculation will look like

                                                                            The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                            Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                            Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                            is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                            defined for liquids

                                                                            Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                            Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                            is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                            A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                            hf = Major losses for entire pipe [L] Also known as friction losses

                                                                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                            hm = Minor losses for entire pipe [L]

                                                                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                            K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                            for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                            P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                            location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                            zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                            V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                            this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                            v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                            Fitting K Fitting K

                                                                            Valves Elbows

                                                                            Globe fully open 10 Regular 90deg flanged 03

                                                                            Angle fully open 2 Regular 90deg threaded 15

                                                                            Gate fully open 015 Long radius 90deg flanged 02

                                                                            Gate 14 closed 026 Long radius 90deg threaded 07

                                                                            Gate 12 closed 21 Long radius 45deg threaded 02

                                                                            Gate 34 closed 17 Regular 45deg threaded 04

                                                                            Swing check forward flow 2

                                                                            Swing check backward flow infinity Tees

                                                                            Line flow flanged 02

                                                                            180deg return bends Line flow threaded 09

                                                                            Flanged 02 Branch flow flanged 10

                                                                            Threaded 15 Branch flow threaded 20

                                                                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                            Square Connection 05 Square Connection 10

                                                                            Rounded Connection 02 Rounded Connection 10

                                                                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                            Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                            The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                            Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                            the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                            Other messagesK must be gt=1 If Q known Solve for D and V

                                                                            3=0 then K must be gt 1 in order to solve

                                                                            Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                            reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                            Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                            Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                            References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                            Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                            Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                            Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                            Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                            Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                            Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                            White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                            copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                            LMNOLMNOengcom httpwwwlmnoengcom

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                                            Circular Pressurized Water Pipes with Pump Curve

                                                                            (Hazen Williams)

                                                                            Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                            (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                            temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                            ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                            curve Darcy-Weisbach with pump curve

                                                                            Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                            Register to enable Calculate button

                                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                            Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                            IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                            function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                            manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                            Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                            Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                            Equations and Methodology Back to Calculations

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                            The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                            calculation will look like

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                            Variables Units L=length P=pressure T=time Back to Calculations

                                                                            A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                            g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                            hf = Major losses for entire pipe [L]

                                                                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                            hm = Minor losses for entire pipe [L]

                                                                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                            k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                            L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                            different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                            program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                            location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                            zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                            this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                            Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                            available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                            and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                            curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                            Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                            Material C Material C

                                                                            Asbestos Cement 140 Copper 130-140

                                                                            Brass 130-140 Galvanized iron 120

                                                                            Brick sewer 100 Glass 140

                                                                            Cast-Iron Lead 130-140

                                                                            New unlined 130 Plastic 140-150

                                                                            10 yr old 107-113 Steel

                                                                            20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                            30 yr old 75-90 New unlined 140-150

                                                                            40 yr old 64-83 Riveted 110

                                                                            ConcreteConcrete-lined

                                                                            Steel forms 140 Tin 130

                                                                            Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                            Centrifugally spun 135 Wood stave (avg condition) 120

                                                                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                            Fitting K Fitting K

                                                                            Valves Elbows

                                                                            Globe fully open 10 Regular 90deg flanged 03

                                                                            Angle fully open 2 Regular 90deg threaded 15

                                                                            Gate fully open 015 Long radius 90deg flanged 02

                                                                            Gate 14 closed 026 Long radius 90deg threaded 07

                                                                            Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                            Gate 34 closed 17 Regular 45deg threaded 04

                                                                            Swing check forward flow 2

                                                                            Swing check backward flow infinity Tees

                                                                            Line flow flanged 02

                                                                            180deg return bends Line flow threaded 09

                                                                            Flanged 02 Branch flow flanged 10

                                                                            Threaded 15 Branch flow threaded 20

                                                                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                            Square Connection 05 Square Connection 10

                                                                            Rounded Connection 02 Rounded Connection 10

                                                                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                            Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                            entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                            One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                            entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                            P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                            to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                            the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                            and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                            pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                            result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                            be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                            lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                            LMNOLMNOengcom httpwwwlmnoengcom

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                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                                            Trapezoidal Open Channel Design Calculation

                                                                            Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                            Froude number Manning coefficient channel slope

                                                                            To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                            Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                                                            Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                            IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                            beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                            The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                            In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                            Variables [] indicates dimensions To calculation

                                                                            A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                            divided by vertical distance

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                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                            Oslash = Angle formed by S

                                                                            Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                            Material Manning n Material Manning n

                                                                            Natural Streams Excavated Earth Channels

                                                                            Clean and Straight 0030 Clean 0022

                                                                            Major Rivers 0035 Gravelly 0025

                                                                            Sluggish with Deep Pools 0040 Weedy 0030

                                                                            Stony Cobbles 0035

                                                                            Metals Floodplains

                                                                            Brass 0011 Pasture Farmland 0035

                                                                            Cast Iron 0013 Light Brush 0050

                                                                            Smooth Steel 0012 Heavy Brush 0075

                                                                            Corrugated Metal 0022 Trees 015

                                                                            Non-Metals

                                                                            Glass 0010 Finished Concrete 0012

                                                                            Clay Tile 0014 Unfinished Concrete 0014

                                                                            Brickwork 0015 Gravel 0029

                                                                            Asphalt 0016 Earth 0025

                                                                            Masonry 0025 Planed Wood 0012

                                                                            Unplaned Wood 0013

                                                                            Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                            Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                            Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                            Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                            The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                            cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                            simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                            The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                            References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                            a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                            c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                            e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                            Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                            French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                            d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                            Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                            b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                            7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                                            Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                            View the version 40 New Features List

                                                                            Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                            AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                            components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                            From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                            View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                            Learn More About AFT Impulse 40

                                                                            Details Views Brochure Demo

                                                                            copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                            • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                              • Local Disk
                                                                                • Circular Culvert Design Calculations Software Equations
                                                                                    • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                                                                        • Culvert Design Inlet and Outlet Control
                                                                                            • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                              • Local Disk
                                                                                                • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                    • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                                        • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                            • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                                • Gradually Varied Flow Calculation Backwater profile
                                                                                                                    • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                                                        • Hydraulic Jump Calculation
                                                                                                                            • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                                                • Manning Equation
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                                                                                                                                        • Non-Circular Open Channel Geometry
                                                                                                                                            • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                                • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                        • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                                • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                    • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                      • Local Disk
                                                                                                                                                                        • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                            • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                              • Local Disk
                                                                                                                                                                                • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                              Equations and Methodology Back to CalculationsThe calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Darcy Weisbach equation for friction losses is used and the calculation includes both laminar and turbulent flow The equations are standard equations which can be found in most fluid mechanics textbooks (see references below) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                              Energy equation with Darcy-Weisbach friction lossesAll equations were compiled from references except for parabolic pump curve equation which is our development The Colebrook equation is an equation representation of the Moody diagram

                                                                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                              fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (3 of 8)12112007 40817 PM

                                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                              calculation will look like

                                                                              The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                              Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                              Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                              is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                              defined for liquids

                                                                              Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                              Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

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                                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                              is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                              A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                              hf = Major losses for entire pipe [L] Also known as friction losses

                                                                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                              hm = Minor losses for entire pipe [L]

                                                                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                              K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                              for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                              P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                              location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                              zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                              V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                              this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                              v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                              Fitting K Fitting K

                                                                              Valves Elbows

                                                                              Globe fully open 10 Regular 90deg flanged 03

                                                                              Angle fully open 2 Regular 90deg threaded 15

                                                                              Gate fully open 015 Long radius 90deg flanged 02

                                                                              Gate 14 closed 026 Long radius 90deg threaded 07

                                                                              Gate 12 closed 21 Long radius 45deg threaded 02

                                                                              Gate 34 closed 17 Regular 45deg threaded 04

                                                                              Swing check forward flow 2

                                                                              Swing check backward flow infinity Tees

                                                                              Line flow flanged 02

                                                                              180deg return bends Line flow threaded 09

                                                                              Flanged 02 Branch flow flanged 10

                                                                              Threaded 15 Branch flow threaded 20

                                                                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                              Square Connection 05 Square Connection 10

                                                                              Rounded Connection 02 Rounded Connection 10

                                                                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                              Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                              The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                              Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                              the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                              Other messagesK must be gt=1 If Q known Solve for D and V

                                                                              3=0 then K must be gt 1 in order to solve

                                                                              Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                              reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                              Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                              Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                              References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                              Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                              Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                              Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                              Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                              Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                              Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                              White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                              copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                              LMNOLMNOengcom httpwwwlmnoengcom

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                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              bull

                                                                              Circular Pressurized Water Pipes with Pump Curve

                                                                              (Hazen Williams)

                                                                              Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                              (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                              temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                              ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                              curve Darcy-Weisbach with pump curve

                                                                              Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                              Register to enable Calculate button

                                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                              Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                              IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                              function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                              manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                              Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                              positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                              Equations and Methodology Back to Calculations

                                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                              calculation will look like

                                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (3 of 8)12112007 40851 PM

                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                              Variables Units L=length P=pressure T=time Back to Calculations

                                                                              A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                              g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                              hf = Major losses for entire pipe [L]

                                                                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                              hm = Minor losses for entire pipe [L]

                                                                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                              k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                              L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                              program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                              location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                              zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                              this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                              Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                              available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                              and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                              Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                              Material C Material C

                                                                              Asbestos Cement 140 Copper 130-140

                                                                              Brass 130-140 Galvanized iron 120

                                                                              Brick sewer 100 Glass 140

                                                                              Cast-Iron Lead 130-140

                                                                              New unlined 130 Plastic 140-150

                                                                              10 yr old 107-113 Steel

                                                                              20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                              30 yr old 75-90 New unlined 140-150

                                                                              40 yr old 64-83 Riveted 110

                                                                              ConcreteConcrete-lined

                                                                              Steel forms 140 Tin 130

                                                                              Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                              Centrifugally spun 135 Wood stave (avg condition) 120

                                                                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                              Fitting K Fitting K

                                                                              Valves Elbows

                                                                              Globe fully open 10 Regular 90deg flanged 03

                                                                              Angle fully open 2 Regular 90deg threaded 15

                                                                              Gate fully open 015 Long radius 90deg flanged 02

                                                                              Gate 14 closed 026 Long radius 90deg threaded 07

                                                                              Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              Gate 34 closed 17 Regular 45deg threaded 04

                                                                              Swing check forward flow 2

                                                                              Swing check backward flow infinity Tees

                                                                              Line flow flanged 02

                                                                              180deg return bends Line flow threaded 09

                                                                              Flanged 02 Branch flow flanged 10

                                                                              Threaded 15 Branch flow threaded 20

                                                                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                              Square Connection 05 Square Connection 10

                                                                              Rounded Connection 02 Rounded Connection 10

                                                                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                              Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                              entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                              One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                              entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                              P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                              to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                              the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                              and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                              pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                              result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                              be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                              lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                              LMNOLMNOengcom httpwwwlmnoengcom

                                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                              bull

                                                                              Trapezoidal Open Channel Design Calculation

                                                                              Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                              Froude number Manning coefficient channel slope

                                                                              To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                              Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                              Register to enable Calculate button

                                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                              Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                              IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                              beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                              The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                              In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                              Variables [] indicates dimensions To calculation

                                                                              A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                              divided by vertical distance

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                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                              Oslash = Angle formed by S

                                                                              Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                              Material Manning n Material Manning n

                                                                              Natural Streams Excavated Earth Channels

                                                                              Clean and Straight 0030 Clean 0022

                                                                              Major Rivers 0035 Gravelly 0025

                                                                              Sluggish with Deep Pools 0040 Weedy 0030

                                                                              Stony Cobbles 0035

                                                                              Metals Floodplains

                                                                              Brass 0011 Pasture Farmland 0035

                                                                              Cast Iron 0013 Light Brush 0050

                                                                              Smooth Steel 0012 Heavy Brush 0075

                                                                              Corrugated Metal 0022 Trees 015

                                                                              Non-Metals

                                                                              Glass 0010 Finished Concrete 0012

                                                                              Clay Tile 0014 Unfinished Concrete 0014

                                                                              Brickwork 0015 Gravel 0029

                                                                              Asphalt 0016 Earth 0025

                                                                              Masonry 0025 Planed Wood 0012

                                                                              Unplaned Wood 0013

                                                                              Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                              Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                              Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                              Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                              The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                              cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                              simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                              The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                              References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                              a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                              c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                              e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                              Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                              French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                              d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                              Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                              b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                              7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                              Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                              Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                              View the version 40 New Features List

                                                                              Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                              AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                              components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                              From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                              View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                              Learn More About AFT Impulse 40

                                                                              Details Views Brochure Demo

                                                                              copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                              • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                • Local Disk
                                                                                  • Circular Culvert Design Calculations Software Equations
                                                                                      • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                        • Local Disk
                                                                                          • Culvert Design Inlet and Outlet Control
                                                                                              • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                • Local Disk
                                                                                                  • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                      • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                        • Local Disk
                                                                                                          • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                              • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                • Local Disk
                                                                                                                  • Gradually Varied Flow Calculation Backwater profile
                                                                                                                      • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                        • Local Disk
                                                                                                                          • Hydraulic Jump Calculation
                                                                                                                              • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                • Local Disk
                                                                                                                                  • Manning Equation
                                                                                                                                      • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                        • Local Disk
                                                                                                                                          • Non-Circular Open Channel Geometry
                                                                                                                                              • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                • Local Disk
                                                                                                                                                  • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                        • Local Disk
                                                                                                                                                          • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                                  • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                      • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                        • Local Disk
                                                                                                                                                                          • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                              • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                • Local Disk
                                                                                                                                                                                  • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                calculation will look like

                                                                                The Colebrook equation is solved for f using Newtons method (Kahaner et al 1989) The remaining calculations are analytic (ie closed form) except Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a cubic solver (Rao 1985) with the result accurate to 8 significant digits Multiple solutions are possible for the three numerical solutions All solutions for both laminar and turbulent flow are automatically determined and shown if they exist All of the calculations utilize double precision

                                                                                Built-in fluid and material propertiesThe user may enter his own fluid properties or select one of the common liquids or gases from the drop-down menu Weight density kinematic viscosity and vapor pressure (if a liquid) for the built-in fluids were obtained from references Likewise the user may enter his own material roughness or select one of the common pipe materials listed in the other drop-down menu Surface roughnesses for the built-in materials were compiled from references

                                                                                Net Positive Suction HeadNPSH is the sum of the heads that push fluid into a pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH available by the piping system (NPSHA)

                                                                                is lower than NPSHR then the pump will not function properly and may overheat NPSH is only

                                                                                defined for liquids

                                                                                Variables Units F=force L=length P=pressure T=time Back to Calculations

                                                                                Fluid density and viscosity may be entered in a wide choice of units Some of the density units are mass density (gcm3 kgm3 slugft3 lb(mass)ft3) and some are weight density (Nm3 lb(force)ft3) There

                                                                                fileE|engineeringhydraulicsPressurized20Liquid20Weisbach20(Moody20diagram)20friction20losseshtm (4 of 8)12112007 40817 PM

                                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                                A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                hf = Major losses for entire pipe [L] Also known as friction losses

                                                                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                hm = Minor losses for entire pipe [L]

                                                                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                                for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                                P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                                Fitting K Fitting K

                                                                                Valves Elbows

                                                                                Globe fully open 10 Regular 90deg flanged 03

                                                                                Angle fully open 2 Regular 90deg threaded 15

                                                                                Gate fully open 015 Long radius 90deg flanged 02

                                                                                Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                Gate 12 closed 21 Long radius 45deg threaded 02

                                                                                Gate 34 closed 17 Regular 45deg threaded 04

                                                                                Swing check forward flow 2

                                                                                Swing check backward flow infinity Tees

                                                                                Line flow flanged 02

                                                                                180deg return bends Line flow threaded 09

                                                                                Flanged 02 Branch flow flanged 10

                                                                                Threaded 15 Branch flow threaded 20

                                                                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                Square Connection 05 Square Connection 10

                                                                                Rounded Connection 02 Rounded Connection 10

                                                                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                                The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                                Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                                the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                                Other messagesK must be gt=1 If Q known Solve for D and V

                                                                                3=0 then K must be gt 1 in order to solve

                                                                                Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                                reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                                Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                                Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                                References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                                Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                                Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                                Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                                Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                                White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                                copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                                                Circular Pressurized Water Pipes with Pump Curve

                                                                                (Hazen Williams)

                                                                                Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                                (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                                temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                                ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                                curve Darcy-Weisbach with pump curve

                                                                                Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

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                                                                                Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                                IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                                function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                                manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                                Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                                positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                                Equations and Methodology Back to Calculations

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                calculation will look like

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                Variables Units L=length P=pressure T=time Back to Calculations

                                                                                A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                hf = Major losses for entire pipe [L]

                                                                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                hm = Minor losses for entire pipe [L]

                                                                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                Material C Material C

                                                                                Asbestos Cement 140 Copper 130-140

                                                                                Brass 130-140 Galvanized iron 120

                                                                                Brick sewer 100 Glass 140

                                                                                Cast-Iron Lead 130-140

                                                                                New unlined 130 Plastic 140-150

                                                                                10 yr old 107-113 Steel

                                                                                20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                30 yr old 75-90 New unlined 140-150

                                                                                40 yr old 64-83 Riveted 110

                                                                                ConcreteConcrete-lined

                                                                                Steel forms 140 Tin 130

                                                                                Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                Fitting K Fitting K

                                                                                Valves Elbows

                                                                                Globe fully open 10 Regular 90deg flanged 03

                                                                                Angle fully open 2 Regular 90deg threaded 15

                                                                                Gate fully open 015 Long radius 90deg flanged 02

                                                                                Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                Gate 34 closed 17 Regular 45deg threaded 04

                                                                                Swing check forward flow 2

                                                                                Swing check backward flow infinity Tees

                                                                                Line flow flanged 02

                                                                                180deg return bends Line flow threaded 09

                                                                                Flanged 02 Branch flow flanged 10

                                                                                Threaded 15 Branch flow threaded 20

                                                                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                Square Connection 05 Square Connection 10

                                                                                Rounded Connection 02 Rounded Connection 10

                                                                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                                                Trapezoidal Open Channel Design Calculation

                                                                                Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                Froude number Manning coefficient channel slope

                                                                                To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

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                                                                                Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                Variables [] indicates dimensions To calculation

                                                                                A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                divided by vertical distance

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                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                Oslash = Angle formed by S

                                                                                Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                Material Manning n Material Manning n

                                                                                Natural Streams Excavated Earth Channels

                                                                                Clean and Straight 0030 Clean 0022

                                                                                Major Rivers 0035 Gravelly 0025

                                                                                Sluggish with Deep Pools 0040 Weedy 0030

                                                                                Stony Cobbles 0035

                                                                                Metals Floodplains

                                                                                Brass 0011 Pasture Farmland 0035

                                                                                Cast Iron 0013 Light Brush 0050

                                                                                Smooth Steel 0012 Heavy Brush 0075

                                                                                Corrugated Metal 0022 Trees 015

                                                                                Non-Metals

                                                                                Glass 0010 Finished Concrete 0012

                                                                                Clay Tile 0014 Unfinished Concrete 0014

                                                                                Brickwork 0015 Gravel 0029

                                                                                Asphalt 0016 Earth 0025

                                                                                Masonry 0025 Planed Wood 0012

                                                                                Unplaned Wood 0013

                                                                                Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                                                Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                View the version 40 New Features List

                                                                                Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                Learn More About AFT Impulse 40

                                                                                Details Views Brochure Demo

                                                                                copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                  • Local Disk
                                                                                    • Circular Culvert Design Calculations Software Equations
                                                                                        • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                          • Local Disk
                                                                                            • Culvert Design Inlet and Outlet Control
                                                                                                • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                                                    • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                                                                                            • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                                                    • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                  is no distinction between lb(mass)ft3 and lb(force)ft3 in the density since they have numerically equivalent values and all densities are internally converted to Nm3 Likewise fluid viscosity may be entered in a wide variety of units Some of the units are dynamic viscosity (cP poise N-sm2 (same as kgm-s) lb(force)-sft2 (same as slugft-s) and some are kinematic viscosity (cSt stoke (same as cm2s) ft2s m2s) All viscosities are internally converted to kinematic viscosity in SI units (m2s) If necessary the equation Kinematic viscosity = Dynamic viscosityMass density is used

                                                                                  A = Pipe area [L2]D = Pipe diameter [L]e = Pipe roughness [L]f = Moody friction factor used in Darcy-Weisbach friction loss equationg = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                  hf = Major losses for entire pipe [L] Also known as friction losses

                                                                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                  hm = Minor losses for entire pipe [L]

                                                                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                  K = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka Only required

                                                                                  for liquidsL = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La Only required for liquids

                                                                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is different from standard atmospheric pressure Be careful - if you change the units of Patm and Pv be sure to enter Patm in the selected units Only required for liquidsPv = Vapor pressure of fluid [P] Expressed as an absolute pressure Only required for liquids

                                                                                  P1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                  location 1 could simply be a location in a pipe upstream of the pump Only required for liquidsP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                  zeroRe = Reynolds numberS = Specific Weight of Fluid (ie weight density weight per unit volume) [FL3] Typical units are Nm3 or lb(force)ft3 Note that S=(mass density)(g)

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                                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                  V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                  this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                  v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                                  Fitting K Fitting K

                                                                                  Valves Elbows

                                                                                  Globe fully open 10 Regular 90deg flanged 03

                                                                                  Angle fully open 2 Regular 90deg threaded 15

                                                                                  Gate fully open 015 Long radius 90deg flanged 02

                                                                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                  Gate 12 closed 21 Long radius 45deg threaded 02

                                                                                  Gate 34 closed 17 Regular 45deg threaded 04

                                                                                  Swing check forward flow 2

                                                                                  Swing check backward flow infinity Tees

                                                                                  Line flow flanged 02

                                                                                  180deg return bends Line flow threaded 09

                                                                                  Flanged 02 Branch flow flanged 10

                                                                                  Threaded 15 Branch flow threaded 20

                                                                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                  Square Connection 05 Square Connection 10

                                                                                  Rounded Connection 02 Rounded Connection 10

                                                                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                  Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                                  The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                                  Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                                  the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                                  Other messagesK must be gt=1 If Q known Solve for D and V

                                                                                  3=0 then K must be gt 1 in order to solve

                                                                                  Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                                  reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                                  Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                                  Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                                  References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                                  Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                                  Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                  Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                  Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                                  Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                                  Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                                  White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                                  copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  bull

                                                                                  Circular Pressurized Water Pipes with Pump Curve

                                                                                  (Hazen Williams)

                                                                                  Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                                  (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                                  temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                                  ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                                  curve Darcy-Weisbach with pump curve

                                                                                  Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

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                                                                                  Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                                  IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                                  function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                                  manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                                  Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                                  positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                                  Equations and Methodology Back to Calculations

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                  Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                  Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                  calculation will look like

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                  Variables Units L=length P=pressure T=time Back to Calculations

                                                                                  A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                  g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                  hf = Major losses for entire pipe [L]

                                                                                  hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                  hm = Minor losses for entire pipe [L]

                                                                                  hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                  H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                  k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                  L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                  NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                  Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                  Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                  program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                  location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                  zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                  this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                  Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                  available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                  and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                  Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                  Material C Material C

                                                                                  Asbestos Cement 140 Copper 130-140

                                                                                  Brass 130-140 Galvanized iron 120

                                                                                  Brick sewer 100 Glass 140

                                                                                  Cast-Iron Lead 130-140

                                                                                  New unlined 130 Plastic 140-150

                                                                                  10 yr old 107-113 Steel

                                                                                  20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                  30 yr old 75-90 New unlined 140-150

                                                                                  40 yr old 64-83 Riveted 110

                                                                                  ConcreteConcrete-lined

                                                                                  Steel forms 140 Tin 130

                                                                                  Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                  Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                  Fitting K Fitting K

                                                                                  Valves Elbows

                                                                                  Globe fully open 10 Regular 90deg flanged 03

                                                                                  Angle fully open 2 Regular 90deg threaded 15

                                                                                  Gate fully open 015 Long radius 90deg flanged 02

                                                                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                  Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  Gate 34 closed 17 Regular 45deg threaded 04

                                                                                  Swing check forward flow 2

                                                                                  Swing check backward flow infinity Tees

                                                                                  Line flow flanged 02

                                                                                  180deg return bends Line flow threaded 09

                                                                                  Flanged 02 Branch flow flanged 10

                                                                                  Threaded 15 Branch flow threaded 20

                                                                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                  Square Connection 05 Square Connection 10

                                                                                  Rounded Connection 02 Rounded Connection 10

                                                                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                  Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                  entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                  One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                  entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                  P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                  to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                  the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                  and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                  pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                  result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                  be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                  lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                  LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                  bull

                                                                                  Trapezoidal Open Channel Design Calculation

                                                                                  Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                  Froude number Manning coefficient channel slope

                                                                                  To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                  Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

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                                                                                  Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                  IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                  beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                  The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                  In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                  Variables [] indicates dimensions To calculation

                                                                                  A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                  divided by vertical distance

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                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                  Oslash = Angle formed by S

                                                                                  Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                  Material Manning n Material Manning n

                                                                                  Natural Streams Excavated Earth Channels

                                                                                  Clean and Straight 0030 Clean 0022

                                                                                  Major Rivers 0035 Gravelly 0025

                                                                                  Sluggish with Deep Pools 0040 Weedy 0030

                                                                                  Stony Cobbles 0035

                                                                                  Metals Floodplains

                                                                                  Brass 0011 Pasture Farmland 0035

                                                                                  Cast Iron 0013 Light Brush 0050

                                                                                  Smooth Steel 0012 Heavy Brush 0075

                                                                                  Corrugated Metal 0022 Trees 015

                                                                                  Non-Metals

                                                                                  Glass 0010 Finished Concrete 0012

                                                                                  Clay Tile 0014 Unfinished Concrete 0014

                                                                                  Brickwork 0015 Gravel 0029

                                                                                  Asphalt 0016 Earth 0025

                                                                                  Masonry 0025 Planed Wood 0012

                                                                                  Unplaned Wood 0013

                                                                                  Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                  Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                  Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                  Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                  The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                  cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                  simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                  The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                  References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                  a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                  c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                  e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                  Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                  French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                  d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                  Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                  b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                  7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                                                  Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

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                                                                                  Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                  AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                  components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                  From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

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                                                                                  Details Views Brochure Demo

                                                                                  copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                                                                      • Circular Culvert Design Calculations Software Equations
                                                                                          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                                                                              • Culvert Design Inlet and Outlet Control
                                                                                                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                                                      • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                          • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                                              • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                  • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                                      • Gradually Varied Flow Calculation Backwater profile
                                                                                                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                                                              • Hydraulic Jump Calculation
                                                                                                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                                                      • Manning Equation
                                                                                                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                                              • Non-Circular Open Channel Geometry
                                                                                                                                                  • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                    V1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                    this value as negative Only required for liquidsZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                    v = Kinematic viscosity of fluid [L2T] greek letter nu Note that kinematic viscosity is equivalent to dynamic (or absolute) viscosity divided by mass density Mass density=Sg

                                                                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from references

                                                                                    Fitting K Fitting K

                                                                                    Valves Elbows

                                                                                    Globe fully open 10 Regular 90deg flanged 03

                                                                                    Angle fully open 2 Regular 90deg threaded 15

                                                                                    Gate fully open 015 Long radius 90deg flanged 02

                                                                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                                                                    Gate 34 closed 17 Regular 45deg threaded 04

                                                                                    Swing check forward flow 2

                                                                                    Swing check backward flow infinity Tees

                                                                                    Line flow flanged 02

                                                                                    180deg return bends Line flow threaded 09

                                                                                    Flanged 02 Branch flow flanged 10

                                                                                    Threaded 15 Branch flow threaded 20

                                                                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

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                                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                    Square Connection 05 Square Connection 10

                                                                                    Rounded Connection 02 Rounded Connection 10

                                                                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                    Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                                    The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                                    Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                                    the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                                    Other messagesK must be gt=1 If Q known Solve for D and V

                                                                                    3=0 then K must be gt 1 in order to solve

                                                                                    Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                                    reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                                    Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                                    Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                                    References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                                    Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                                    Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                    Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                    Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                                    Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                                    Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                                    White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                                    copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                    LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    bull

                                                                                    Circular Pressurized Water Pipes with Pump Curve

                                                                                    (Hazen Williams)

                                                                                    Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                                    (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                                    temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                                    ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                                    curve Darcy-Weisbach with pump curve

                                                                                    Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                                    Register to enable Calculate button

                                                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                    Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                                    IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                                    function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                                    manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                                    Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                                    positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                                    Equations and Methodology Back to Calculations

                                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (2 of 8)12112007 40851 PM

                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                    Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                    Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                    calculation will look like

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                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                    Variables Units L=length P=pressure T=time Back to Calculations

                                                                                    A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                    g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                    hf = Major losses for entire pipe [L]

                                                                                    hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                    hm = Minor losses for entire pipe [L]

                                                                                    hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                    H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                    k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                    L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                    NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                    Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                    Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                    program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                    to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                    location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                    Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                    zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                    reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                    V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                    reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                    of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                    Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                    this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                    Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                    available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                    and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                    Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                    Material C Material C

                                                                                    Asbestos Cement 140 Copper 130-140

                                                                                    Brass 130-140 Galvanized iron 120

                                                                                    Brick sewer 100 Glass 140

                                                                                    Cast-Iron Lead 130-140

                                                                                    New unlined 130 Plastic 140-150

                                                                                    10 yr old 107-113 Steel

                                                                                    20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                    30 yr old 75-90 New unlined 140-150

                                                                                    40 yr old 64-83 Riveted 110

                                                                                    ConcreteConcrete-lined

                                                                                    Steel forms 140 Tin 130

                                                                                    Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                    Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                    Fitting K Fitting K

                                                                                    Valves Elbows

                                                                                    Globe fully open 10 Regular 90deg flanged 03

                                                                                    Angle fully open 2 Regular 90deg threaded 15

                                                                                    Gate fully open 015 Long radius 90deg flanged 02

                                                                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                    Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    Gate 34 closed 17 Regular 45deg threaded 04

                                                                                    Swing check forward flow 2

                                                                                    Swing check backward flow infinity Tees

                                                                                    Line flow flanged 02

                                                                                    180deg return bends Line flow threaded 09

                                                                                    Flanged 02 Branch flow flanged 10

                                                                                    Threaded 15 Branch flow threaded 20

                                                                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                    Square Connection 05 Square Connection 10

                                                                                    Rounded Connection 02 Rounded Connection 10

                                                                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                    Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                    entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                    One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                    entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                    P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                    to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                    the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                    and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                    pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                    result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                    be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                    lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                    LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                    bull

                                                                                    Trapezoidal Open Channel Design Calculation

                                                                                    Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                    Froude number Manning coefficient channel slope

                                                                                    To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                    Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                    Register to enable Calculate button

                                                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                    Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                    IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                    beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                    The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                    Variables [] indicates dimensions To calculation

                                                                                    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                    divided by vertical distance

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                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                    Oslash = Angle formed by S

                                                                                    Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                    Material Manning n Material Manning n

                                                                                    Natural Streams Excavated Earth Channels

                                                                                    Clean and Straight 0030 Clean 0022

                                                                                    Major Rivers 0035 Gravelly 0025

                                                                                    Sluggish with Deep Pools 0040 Weedy 0030

                                                                                    Stony Cobbles 0035

                                                                                    Metals Floodplains

                                                                                    Brass 0011 Pasture Farmland 0035

                                                                                    Cast Iron 0013 Light Brush 0050

                                                                                    Smooth Steel 0012 Heavy Brush 0075

                                                                                    Corrugated Metal 0022 Trees 015

                                                                                    Non-Metals

                                                                                    Glass 0010 Finished Concrete 0012

                                                                                    Clay Tile 0014 Unfinished Concrete 0014

                                                                                    Brickwork 0015 Gravel 0029

                                                                                    Asphalt 0016 Earth 0025

                                                                                    Masonry 0025 Planed Wood 0012

                                                                                    Unplaned Wood 0013

                                                                                    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                    Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                    The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                    cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                    simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                    The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                    References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                    a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                    Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                    French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                    Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                    7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

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                                                                                    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                    View the version 40 New Features List

                                                                                    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                    Learn More About AFT Impulse 40

                                                                                    Details Views Brochure Demo

                                                                                    copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                      • Local Disk
                                                                                        • Circular Culvert Design Calculations Software Equations
                                                                                            • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                              • Local Disk
                                                                                                • Culvert Design Inlet and Outlet Control
                                                                                                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                      • Local Disk
                                                                                                        • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                            • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                              • Local Disk
                                                                                                                • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                    • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                                        • Gradually Varied Flow Calculation Backwater profile
                                                                                                                            • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                              • Local Disk
                                                                                                                                • Hydraulic Jump Calculation
                                                                                                                                    • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                      • Local Disk
                                                                                                                                        • Manning Equation
                                                                                                                                            • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                                                • Non-Circular Open Channel Geometry
                                                                                                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                      Square Connection 05 Square Connection 10

                                                                                      Rounded Connection 02 Rounded Connection 10

                                                                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                      Error Messages Back to CalculationsThe following are input checks and will appear if an input is physically impossible such as a negative lengthQ V D L must be gt 0 Density Viscosity must be gt 0 K must be gt= 0 e must be gt= 0 Qmax Hmax must be gt 0 Q must be lt= Qmax

                                                                                      The following are input checks for liquids onlyLa Ka must be gt= 0 Vapor and Atm P must be gt 0

                                                                                      Need Lalt=L and Kalt=K Length of the suction pipe (Pipe A) was entered as being longer than all of

                                                                                      the pipe or K for the suction pipe was entered as greater than K for the entire system

                                                                                      Other messagesK must be gt=1 If Q known Solve for D and V

                                                                                      3=0 then K must be gt 1 in order to solve

                                                                                      Tanks open so P1-P3=0 for B Cannot solve for pressure difference if using Scenario B since

                                                                                      reservoirs are defined to be at zero pressure thus zero pressure difference

                                                                                      Infeasible input Hlt0 Infeasible input hmlt0 Infeasible input hf lt=0 Re or eD out of range

                                                                                      Infeasible Losses will be lt=0 f wont be 0008 to 01 f will be too small f will be too large Re will be gt 1e8 Infeasible input One of these messages will appear if each of your inputs is okay but they combine to give no possible solution For instance if you are solving for pipe diameter and your input data will result in negative losses regardless of pipe diameter then your data are infeasible

                                                                                      References Back to CalculationsNumerical methods citationsKahaner D C Moler S Nash 1989 Numerical methods and software Prentice-Hall Inc

                                                                                      Rao S S 1985 Optimization theory and applications Wiley Eastern Limited 2ed

                                                                                      Fluid mechanics referencesGerhart P M R J Gross and J I Hochstein 1992 Fundamentals of Fluid Mechanics Addison-Wesley Pubishing Co 2ed

                                                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                      Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                      Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                                      Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                                      Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                                      White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                                      copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                      LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

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                                                                                      Circular Pressurized Water Pipes with Pump Curve

                                                                                      (Hazen Williams)

                                                                                      Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                                      (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                                      temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                                      ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                                      curve Darcy-Weisbach with pump curve

                                                                                      Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                                      Register to enable Calculate button

                                                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                      Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                                      IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                                      function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                                      manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                                      Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                      Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                                      positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                                      Equations and Methodology Back to Calculations

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                      The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                      Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                      Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                      calculation will look like

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                      All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                      Variables Units L=length P=pressure T=time Back to Calculations

                                                                                      A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                      g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                      hf = Major losses for entire pipe [L]

                                                                                      hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                      hm = Minor losses for entire pipe [L]

                                                                                      hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                      H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                      k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                      L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                      NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                      Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                      Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                      different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                      program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                      to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                      location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                      Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                      zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                      reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                      V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                      reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                      of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                      Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                      this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                      Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                      available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                      and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                      curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                      Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                      Material C Material C

                                                                                      Asbestos Cement 140 Copper 130-140

                                                                                      Brass 130-140 Galvanized iron 120

                                                                                      Brick sewer 100 Glass 140

                                                                                      Cast-Iron Lead 130-140

                                                                                      New unlined 130 Plastic 140-150

                                                                                      10 yr old 107-113 Steel

                                                                                      20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                      30 yr old 75-90 New unlined 140-150

                                                                                      40 yr old 64-83 Riveted 110

                                                                                      ConcreteConcrete-lined

                                                                                      Steel forms 140 Tin 130

                                                                                      Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                      Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                      Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                      Fitting K Fitting K

                                                                                      Valves Elbows

                                                                                      Globe fully open 10 Regular 90deg flanged 03

                                                                                      Angle fully open 2 Regular 90deg threaded 15

                                                                                      Gate fully open 015 Long radius 90deg flanged 02

                                                                                      Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                      Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                      Gate 34 closed 17 Regular 45deg threaded 04

                                                                                      Swing check forward flow 2

                                                                                      Swing check backward flow infinity Tees

                                                                                      Line flow flanged 02

                                                                                      180deg return bends Line flow threaded 09

                                                                                      Flanged 02 Branch flow flanged 10

                                                                                      Threaded 15 Branch flow threaded 20

                                                                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                      Square Connection 05 Square Connection 10

                                                                                      Rounded Connection 02 Rounded Connection 10

                                                                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                      Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                      entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                      One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                      entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                      P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                      to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                      the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                      and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                      pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                      result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                      be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                      lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                      LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                      bull

                                                                                      Trapezoidal Open Channel Design Calculation

                                                                                      Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                      Froude number Manning coefficient channel slope

                                                                                      To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                      Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                      Register to enable Calculate button

                                                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                      Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                      IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                      beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                      The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                      In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                      Variables [] indicates dimensions To calculation

                                                                                      A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                      divided by vertical distance

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                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                      Oslash = Angle formed by S

                                                                                      Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                      Material Manning n Material Manning n

                                                                                      Natural Streams Excavated Earth Channels

                                                                                      Clean and Straight 0030 Clean 0022

                                                                                      Major Rivers 0035 Gravelly 0025

                                                                                      Sluggish with Deep Pools 0040 Weedy 0030

                                                                                      Stony Cobbles 0035

                                                                                      Metals Floodplains

                                                                                      Brass 0011 Pasture Farmland 0035

                                                                                      Cast Iron 0013 Light Brush 0050

                                                                                      Smooth Steel 0012 Heavy Brush 0075

                                                                                      Corrugated Metal 0022 Trees 015

                                                                                      Non-Metals

                                                                                      Glass 0010 Finished Concrete 0012

                                                                                      Clay Tile 0014 Unfinished Concrete 0014

                                                                                      Brickwork 0015 Gravel 0029

                                                                                      Asphalt 0016 Earth 0025

                                                                                      Masonry 0025 Planed Wood 0012

                                                                                      Unplaned Wood 0013

                                                                                      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                      Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                      The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                      cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                      simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                      The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                      References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                      a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                      Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                      French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                      Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                      7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                      Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                                      Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                      View the version 40 New Features List

                                                                                      Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                      AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                      From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                      View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                      Learn More About AFT Impulse 40

                                                                                      Details Views Brochure Demo

                                                                                      copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                        • Local Disk
                                                                                          • Circular Culvert Design Calculations Software Equations
                                                                                              • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                • Local Disk
                                                                                                  • Culvert Design Inlet and Outlet Control
                                                                                                      • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                        • Local Disk
                                                                                                          • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                              • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                • Local Disk
                                                                                                                  • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                      • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                                          • Gradually Varied Flow Calculation Backwater profile
                                                                                                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                                                                  • Hydraulic Jump Calculation
                                                                                                                                      • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                                                          • Manning Equation
                                                                                                                                              • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
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                                                                                                                                                  • Non-Circular Open Channel Geometry
                                                                                                                                                      • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                              • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
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                                                                                                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                        Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses

                                                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                        Potter M C and D C Wiggert 1991 Mechanics of Fluids Prentice-Hall Inc

                                                                                        Roberson J A and C T Crowe 1990 Engineering Fluid Mechanics Houghton Mifflin Co

                                                                                        Streeter V L E B Wylie and K W Bedford 1998 Fluid Mechanics WCBMcGraw-Hill 9ed

                                                                                        White F M 1979 Fluid Mechanics McGraw-Hill Inc

                                                                                        copy 2001 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        bull

                                                                                        Circular Pressurized Water Pipes with Pump Curve

                                                                                        (Hazen Williams)

                                                                                        Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                                        (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                                        temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                                        ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                                        curve Darcy-Weisbach with pump curve

                                                                                        Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                                        Register to enable Calculate button

                                                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                        Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                                        IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                                        function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                                        manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                                        Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                                        positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                                        Equations and Methodology Back to Calculations

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                        Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                        Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                        calculation will look like

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                        Variables Units L=length P=pressure T=time Back to Calculations

                                                                                        A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                        g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                        hf = Major losses for entire pipe [L]

                                                                                        hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                        hm = Minor losses for entire pipe [L]

                                                                                        hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                        H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                        k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                        L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                        NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                        Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                        Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                        program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                        to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                        location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                        Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                        zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                        reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                        V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                        reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                        of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                        Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                        this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                        Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                        available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                        and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                        Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                        Material C Material C

                                                                                        Asbestos Cement 140 Copper 130-140

                                                                                        Brass 130-140 Galvanized iron 120

                                                                                        Brick sewer 100 Glass 140

                                                                                        Cast-Iron Lead 130-140

                                                                                        New unlined 130 Plastic 140-150

                                                                                        10 yr old 107-113 Steel

                                                                                        20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                        30 yr old 75-90 New unlined 140-150

                                                                                        40 yr old 64-83 Riveted 110

                                                                                        ConcreteConcrete-lined

                                                                                        Steel forms 140 Tin 130

                                                                                        Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                        Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                        Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                        Fitting K Fitting K

                                                                                        Valves Elbows

                                                                                        Globe fully open 10 Regular 90deg flanged 03

                                                                                        Angle fully open 2 Regular 90deg threaded 15

                                                                                        Gate fully open 015 Long radius 90deg flanged 02

                                                                                        Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                        Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        Gate 34 closed 17 Regular 45deg threaded 04

                                                                                        Swing check forward flow 2

                                                                                        Swing check backward flow infinity Tees

                                                                                        Line flow flanged 02

                                                                                        180deg return bends Line flow threaded 09

                                                                                        Flanged 02 Branch flow flanged 10

                                                                                        Threaded 15 Branch flow threaded 20

                                                                                        Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                        Square Connection 05 Square Connection 10

                                                                                        Rounded Connection 02 Rounded Connection 10

                                                                                        Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                        Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                        entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                        One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                        entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                        P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                        to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                        the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                        and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                        pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                        result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                        be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                        lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                        LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

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                                                                                        Trapezoidal Open Channel Design Calculation

                                                                                        Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                        Froude number Manning coefficient channel slope

                                                                                        To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                        Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                        Register to enable Calculate button

                                                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                        Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                        IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                        beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                        The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                        In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                        Variables [] indicates dimensions To calculation

                                                                                        A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                        divided by vertical distance

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                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                        Oslash = Angle formed by S

                                                                                        Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                        Material Manning n Material Manning n

                                                                                        Natural Streams Excavated Earth Channels

                                                                                        Clean and Straight 0030 Clean 0022

                                                                                        Major Rivers 0035 Gravelly 0025

                                                                                        Sluggish with Deep Pools 0040 Weedy 0030

                                                                                        Stony Cobbles 0035

                                                                                        Metals Floodplains

                                                                                        Brass 0011 Pasture Farmland 0035

                                                                                        Cast Iron 0013 Light Brush 0050

                                                                                        Smooth Steel 0012 Heavy Brush 0075

                                                                                        Corrugated Metal 0022 Trees 015

                                                                                        Non-Metals

                                                                                        Glass 0010 Finished Concrete 0012

                                                                                        Clay Tile 0014 Unfinished Concrete 0014

                                                                                        Brickwork 0015 Gravel 0029

                                                                                        Asphalt 0016 Earth 0025

                                                                                        Masonry 0025 Planed Wood 0012

                                                                                        Unplaned Wood 0013

                                                                                        Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                        Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                        Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                        Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                        The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                        cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                        simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                        The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                        References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                        a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                        Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                        French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                        Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                        7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                        Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                                        Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                        View the version 40 New Features List

                                                                                        Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                        AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                        components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                        From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                        View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                        Learn More About AFT Impulse 40

                                                                                        Details Views Brochure Demo

                                                                                        copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                        • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
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                                                                                            • Circular Culvert Design Calculations Software Equations
                                                                                                • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
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                                                                                                    • Culvert Design Inlet and Outlet Control
                                                                                                        • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                                                            • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                                                    • DPlot Graphing Software for Scientists and Engineers - Home Page
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                                                                                                                                    • Hydraulic Jump Calculation
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                                                                                                                                            • Manning Equation
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                                                                                                                                                    • Non-Circular Open Channel Geometry
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                                                                                                                                                            • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                                    • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                                                            • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                                                    • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
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                                                                                                                                                                                            • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          bull

                                                                                          Circular Pressurized Water Pipes with Pump Curve

                                                                                          (Hazen Williams)

                                                                                          Compute flow (ie discharge capacity) velocity pipe diameter length elevation difference pressure difference major losses

                                                                                          (using Hazen Williams coefficient) minor losses total dynamic head net positive suction head User enters two points on pump curve - Head at no flow and Flow at no head Parabolic shaped pump curve is formed from the two points Valid for water at

                                                                                          temperatures typical of city water supply systems (40 to 75 oF 4 to 25 oC)

                                                                                          ToOther single pipe calculators Hazen-Williams without pump curve Darcy-Weisbach without pump

                                                                                          curve Darcy-Weisbach with pump curve

                                                                                          Multiple pipes Bypass Loop Pipe NetworkLMNO Engineering home page Unit Conversions Page Trouble printing

                                                                                          Register to enable Calculate button

                                                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                          Topics Scenarios Common Questions Equations Variables Hazen Williams Coefficients Minor Loss Coefficients Error Messages

                                                                                          IntroductionThe Hazen Williams equation for major (friction) losses is commonly used by engineers for designing and analyzing piping systems carrying water at typical temperatures of municipal water supplies (40 to 75 oF 4 to 25 oC) A pump curve is incorporated into the calculation to simulate flows containing centrifugal pumps or other pumps that have a pump curve To keep the calculations input relatively simple we only require you to enter two points on the pump curve - flow at zero head and head at zero flow A parabolic curve is then formed between the two points as shown in Equations below The calculation also asks for information specifically about the pipe on the suction side of the pump This information is used to compute the net positive suction head available (NPSHA) For a pump to properly

                                                                                          function the NPSHA must be greater than the NPSH required by the pump (obtained from the pump

                                                                                          manufacturer) If your system does not require a pump or uses a pump that does not have a parabolically shaped pump curve then our other Hazen Williams design calculation may be more helpful

                                                                                          Piping ScenariosPipe A is the pipe upstream from the pump (ie the suction side pipe)

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                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                                          positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                                          Equations and Methodology Back to Calculations

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                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                          Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                          Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                          calculation will look like

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                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                          Variables Units L=length P=pressure T=time Back to Calculations

                                                                                          A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                          g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                          hf = Major losses for entire pipe [L]

                                                                                          hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                          hm = Minor losses for entire pipe [L]

                                                                                          hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                          H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                          k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                          L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                          NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                          Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                          Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                          program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                          to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                          location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                          Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                          zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                          reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                          V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                          reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                          of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                          Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                          this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                          Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                          available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                          and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                          Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                          Material C Material C

                                                                                          Asbestos Cement 140 Copper 130-140

                                                                                          Brass 130-140 Galvanized iron 120

                                                                                          Brick sewer 100 Glass 140

                                                                                          Cast-Iron Lead 130-140

                                                                                          New unlined 130 Plastic 140-150

                                                                                          10 yr old 107-113 Steel

                                                                                          20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                          30 yr old 75-90 New unlined 140-150

                                                                                          40 yr old 64-83 Riveted 110

                                                                                          ConcreteConcrete-lined

                                                                                          Steel forms 140 Tin 130

                                                                                          Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                          Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                          Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                          Fitting K Fitting K

                                                                                          Valves Elbows

                                                                                          Globe fully open 10 Regular 90deg flanged 03

                                                                                          Angle fully open 2 Regular 90deg threaded 15

                                                                                          Gate fully open 015 Long radius 90deg flanged 02

                                                                                          Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                          Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          Gate 34 closed 17 Regular 45deg threaded 04

                                                                                          Swing check forward flow 2

                                                                                          Swing check backward flow infinity Tees

                                                                                          Line flow flanged 02

                                                                                          180deg return bends Line flow threaded 09

                                                                                          Flanged 02 Branch flow flanged 10

                                                                                          Threaded 15 Branch flow threaded 20

                                                                                          Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                          Square Connection 05 Square Connection 10

                                                                                          Rounded Connection 02 Rounded Connection 10

                                                                                          Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                          Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                          entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                          One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                          entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                          P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                          to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                          the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                          and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                          pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                          Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                          result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                          be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                          lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                          LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                          LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                          bull

                                                                                          Trapezoidal Open Channel Design Calculation

                                                                                          Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                          Froude number Manning coefficient channel slope

                                                                                          To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                          Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                          Register to enable Calculate button

                                                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                          Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                          IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                          beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                          The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                          In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                          Variables [] indicates dimensions To calculation

                                                                                          A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                          divided by vertical distance

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                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                          Oslash = Angle formed by S

                                                                                          Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                          Material Manning n Material Manning n

                                                                                          Natural Streams Excavated Earth Channels

                                                                                          Clean and Straight 0030 Clean 0022

                                                                                          Major Rivers 0035 Gravelly 0025

                                                                                          Sluggish with Deep Pools 0040 Weedy 0030

                                                                                          Stony Cobbles 0035

                                                                                          Metals Floodplains

                                                                                          Brass 0011 Pasture Farmland 0035

                                                                                          Cast Iron 0013 Light Brush 0050

                                                                                          Smooth Steel 0012 Heavy Brush 0075

                                                                                          Corrugated Metal 0022 Trees 015

                                                                                          Non-Metals

                                                                                          Glass 0010 Finished Concrete 0012

                                                                                          Clay Tile 0014 Unfinished Concrete 0014

                                                                                          Brickwork 0015 Gravel 0029

                                                                                          Asphalt 0016 Earth 0025

                                                                                          Masonry 0025 Planed Wood 0012

                                                                                          Unplaned Wood 0013

                                                                                          Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                          Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                          Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                          Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                          The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                          cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                          simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                          The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                          References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                          a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                          c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                          e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                          Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                          French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                          d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                          Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                          b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                          7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                          Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                                          Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                          View the version 40 New Features List

                                                                                          Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                          AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                          components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                          From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                          View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                          Learn More About AFT Impulse 40

                                                                                          Details Views Brochure Demo

                                                                                          copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                          • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                            • Local Disk
                                                                                              • Circular Culvert Design Calculations Software Equations
                                                                                                  • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                    • Local Disk
                                                                                                      • Culvert Design Inlet and Outlet Control
                                                                                                          • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                            • Local Disk
                                                                                                              • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                  • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
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                                                                                                                      • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                          • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                                              • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                  • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
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                                                                                                                                      • Hydraulic Jump Calculation
                                                                                                                                          • file____E__engineering_hydraulics_Manning20Equationpdf
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                                                                                                                                              • Manning Equation
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                                                                                                                                                      • Non-Circular Open Channel Geometry
                                                                                                                                                          • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
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                                                                                                                                                              • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                                      • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                                              • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                                                      • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                          • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                            • Local Disk
                                                                                                                                                                                              • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                            Convention for Z1-Z2 and Z1-Z3 If location 1 is above location 2 then Z1-Z2 should be entered as

                                                                                            positive If location 2 is above location 1 then Z1-Z2 should be entered as negative Likewise for Z1-Z3

                                                                                            Equations and Methodology Back to Calculations

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                                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                            The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                            Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                            Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                            calculation will look like

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                                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                            All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                            Variables Units L=length P=pressure T=time Back to Calculations

                                                                                            A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                            g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                            hf = Major losses for entire pipe [L]

                                                                                            hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                            hm = Minor losses for entire pipe [L]

                                                                                            hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                            H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                            k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                            L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                            NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                            Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                            Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                            different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                            program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                            to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                            location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                            Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                            zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                            reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                            V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                            reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                            of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                            Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                            this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                            Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                            available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                            and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                            curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                            Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                            Material C Material C

                                                                                            Asbestos Cement 140 Copper 130-140

                                                                                            Brass 130-140 Galvanized iron 120

                                                                                            Brick sewer 100 Glass 140

                                                                                            Cast-Iron Lead 130-140

                                                                                            New unlined 130 Plastic 140-150

                                                                                            10 yr old 107-113 Steel

                                                                                            20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                            30 yr old 75-90 New unlined 140-150

                                                                                            40 yr old 64-83 Riveted 110

                                                                                            ConcreteConcrete-lined

                                                                                            Steel forms 140 Tin 130

                                                                                            Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                            Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                            Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                            Fitting K Fitting K

                                                                                            Valves Elbows

                                                                                            Globe fully open 10 Regular 90deg flanged 03

                                                                                            Angle fully open 2 Regular 90deg threaded 15

                                                                                            Gate fully open 015 Long radius 90deg flanged 02

                                                                                            Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                            Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                            Gate 34 closed 17 Regular 45deg threaded 04

                                                                                            Swing check forward flow 2

                                                                                            Swing check backward flow infinity Tees

                                                                                            Line flow flanged 02

                                                                                            180deg return bends Line flow threaded 09

                                                                                            Flanged 02 Branch flow flanged 10

                                                                                            Threaded 15 Branch flow threaded 20

                                                                                            Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                            Square Connection 05 Square Connection 10

                                                                                            Rounded Connection 02 Rounded Connection 10

                                                                                            Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                            Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                            entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                            One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                            entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                            P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                            to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                            the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                            and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                            pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                            Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                            result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                            be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                            lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                            LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                            LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                            bull

                                                                                            Trapezoidal Open Channel Design Calculation

                                                                                            Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                            Froude number Manning coefficient channel slope

                                                                                            To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                            Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                            LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                            Register to enable Calculate button

                                                                                            Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                            Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                            IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                            beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                            The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                            In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                            Variables [] indicates dimensions To calculation

                                                                                            A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                            divided by vertical distance

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                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                            Oslash = Angle formed by S

                                                                                            Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                            Material Manning n Material Manning n

                                                                                            Natural Streams Excavated Earth Channels

                                                                                            Clean and Straight 0030 Clean 0022

                                                                                            Major Rivers 0035 Gravelly 0025

                                                                                            Sluggish with Deep Pools 0040 Weedy 0030

                                                                                            Stony Cobbles 0035

                                                                                            Metals Floodplains

                                                                                            Brass 0011 Pasture Farmland 0035

                                                                                            Cast Iron 0013 Light Brush 0050

                                                                                            Smooth Steel 0012 Heavy Brush 0075

                                                                                            Corrugated Metal 0022 Trees 015

                                                                                            Non-Metals

                                                                                            Glass 0010 Finished Concrete 0012

                                                                                            Clay Tile 0014 Unfinished Concrete 0014

                                                                                            Brickwork 0015 Gravel 0029

                                                                                            Asphalt 0016 Earth 0025

                                                                                            Masonry 0025 Planed Wood 0012

                                                                                            Unplaned Wood 0013

                                                                                            Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                            Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                            Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                            Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                            The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                            cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                            simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                            The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                            References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                            a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                            c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                            e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                            Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                            French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                            d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                            Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                            b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                            7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                            Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                                            Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                            View the version 40 New Features List

                                                                                            Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                            AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                            components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                            From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                            View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                            Learn More About AFT Impulse 40

                                                                                            Details Views Brochure Demo

                                                                                            copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                            • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                              • Local Disk
                                                                                                • Circular Culvert Design Calculations Software Equations
                                                                                                    • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                      • Local Disk
                                                                                                        • Culvert Design Inlet and Outlet Control
                                                                                                            • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
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                                                                                                                • Design of Circular Water Pipes using Hazen Williams Equation
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                                                                                                                        • DPlot Graphing Software for Scientists and Engineers - Home Page
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                                                                                                                                • Gradually Varied Flow Calculation Backwater profile
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                                                                                                                                        • Hydraulic Jump Calculation
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                                                                                                                                                • Manning Equation
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                                                                                                                                                        • Non-Circular Open Channel Geometry
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                                                                                                                                                                • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
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                                                                                                                                                                        • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
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                                                                                                                                                                                • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
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                                                                                                                                                                                        • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                            • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
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                                                                                                                                                                                                • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                              The calculation on this page uses the steady state energy equation Minor losses (due to valves pipe bends etc) and major losses (due to pipe friction) are included The Hazen Williams equation for friction losses is used The equations are standard equations which can be found in most fluid mechanics textbooks (see References) A pump curve is included in the calculation Determination of the pump curve requires that the user enter the two extreme points on the curve - head when capacity is zero and capacity when head is zero Then a parabola with a negative curvature is fit through the two points This parabola is used since it is a good approximation of a typical pump curve and does not require users to enter a multitude of data points And oftentimes pump catalogs only give the two extreme points on the curve rather than a graph showing the complete curve

                                                                                              Pump CurveTo provide an example of a pump curve developed using the equation H=Hmax[1-(QQmax)2] let

                                                                                              Qmax=1500 gpm (when head is zero) and Hmax=900 ft (when Q is zero) The pump curve used in the

                                                                                              calculation will look like

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                                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                              All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                              Variables Units L=length P=pressure T=time Back to Calculations

                                                                                              A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                              g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                              hf = Major losses for entire pipe [L]

                                                                                              hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                              hm = Minor losses for entire pipe [L]

                                                                                              hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                              H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                              k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                              L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                              NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                              Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                              Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                              different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                              program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                              to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                              location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                              Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                              zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                              reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                              V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                              reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                              of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                              Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                              this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                              Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                              available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                              and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                              curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                              Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                              Material C Material C

                                                                                              Asbestos Cement 140 Copper 130-140

                                                                                              Brass 130-140 Galvanized iron 120

                                                                                              Brick sewer 100 Glass 140

                                                                                              Cast-Iron Lead 130-140

                                                                                              New unlined 130 Plastic 140-150

                                                                                              10 yr old 107-113 Steel

                                                                                              20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                              30 yr old 75-90 New unlined 140-150

                                                                                              40 yr old 64-83 Riveted 110

                                                                                              ConcreteConcrete-lined

                                                                                              Steel forms 140 Tin 130

                                                                                              Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                              Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                              Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                              Fitting K Fitting K

                                                                                              Valves Elbows

                                                                                              Globe fully open 10 Regular 90deg flanged 03

                                                                                              Angle fully open 2 Regular 90deg threaded 15

                                                                                              Gate fully open 015 Long radius 90deg flanged 02

                                                                                              Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                              Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                              Gate 34 closed 17 Regular 45deg threaded 04

                                                                                              Swing check forward flow 2

                                                                                              Swing check backward flow infinity Tees

                                                                                              Line flow flanged 02

                                                                                              180deg return bends Line flow threaded 09

                                                                                              Flanged 02 Branch flow flanged 10

                                                                                              Threaded 15 Branch flow threaded 20

                                                                                              Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                              Square Connection 05 Square Connection 10

                                                                                              Rounded Connection 02 Rounded Connection 10

                                                                                              Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                              Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                              entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                              One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                              entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                              P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                              to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                              the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                              and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                              pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

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                                                                                              Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                              result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                              be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                              lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                              LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                              LMNOLMNOengcom httpwwwlmnoengcom

                                                                                              fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                              bull

                                                                                              Trapezoidal Open Channel Design Calculation

                                                                                              Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                              Froude number Manning coefficient channel slope

                                                                                              To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                              Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                              LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                              Register to enable Calculate button

                                                                                              Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                              Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                              IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

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                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                              beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                              The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                              In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                              Variables [] indicates dimensions To calculation

                                                                                              A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                              divided by vertical distance

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                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                              Oslash = Angle formed by S

                                                                                              Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                              Material Manning n Material Manning n

                                                                                              Natural Streams Excavated Earth Channels

                                                                                              Clean and Straight 0030 Clean 0022

                                                                                              Major Rivers 0035 Gravelly 0025

                                                                                              Sluggish with Deep Pools 0040 Weedy 0030

                                                                                              Stony Cobbles 0035

                                                                                              Metals Floodplains

                                                                                              Brass 0011 Pasture Farmland 0035

                                                                                              Cast Iron 0013 Light Brush 0050

                                                                                              Smooth Steel 0012 Heavy Brush 0075

                                                                                              Corrugated Metal 0022 Trees 015

                                                                                              Non-Metals

                                                                                              Glass 0010 Finished Concrete 0012

                                                                                              Clay Tile 0014 Unfinished Concrete 0014

                                                                                              Brickwork 0015 Gravel 0029

                                                                                              Asphalt 0016 Earth 0025

                                                                                              Masonry 0025 Planed Wood 0012

                                                                                              Unplaned Wood 0013

                                                                                              Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                              Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                              Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                              Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                              The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                              cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                              simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                              The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                              References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                              a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                              c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                              e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                              Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                              French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                              d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                              Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                              b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                              7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                              Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                                              Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                              View the version 40 New Features List

                                                                                              Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                              AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                              components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                              From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                              View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                              Learn More About AFT Impulse 40

                                                                                              Details Views Brochure Demo

                                                                                              copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                              • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                • Local Disk
                                                                                                  • Circular Culvert Design Calculations Software Equations
                                                                                                      • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                        • Local Disk
                                                                                                          • Culvert Design Inlet and Outlet Control
                                                                                                              • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                • Local Disk
                                                                                                                  • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                      • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                        • Local Disk
                                                                                                                          • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                              • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
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                                                                                                                                  • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                      • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                        • Local Disk
                                                                                                                                          • Hydraulic Jump Calculation
                                                                                                                                              • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                • Local Disk
                                                                                                                                                  • Manning Equation
                                                                                                                                                      • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                        • Local Disk
                                                                                                                                                          • Non-Circular Open Channel Geometry
                                                                                                                                                              • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                • Local Disk
                                                                                                                                                                  • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                        • Local Disk
                                                                                                                                                                          • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
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                                                                                                                                                                                  • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                      • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                          • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                              • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                • Local Disk
                                                                                                                                                                                                  • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                All of the calculations on this page have analytic (closed form) solutions except for Solve for V Q Q known Solve for Diameter and V known Solve for Diameter These three calculations required a numerical solution Our solution utilizes a modified implementation of Newtons method that finds roots of the equations with the result accurate to 8 significant digits All of the calculations utilize double precision V known Solve for Diameter may find two diameters which give the same velocity - if this is the case both diameters are shown

                                                                                                Variables Units L=length P=pressure T=time Back to Calculations

                                                                                                A = Pipe area [L2]C = Hazen-Williams coefficient See table belowD = Pipe diameter [L]DH = Driving Head [L] = left side of the first equation above

                                                                                                g = Acceleration due to gravity = 32174 fts2 = 98066 ms2

                                                                                                hf = Major losses for entire pipe [L]

                                                                                                hfA = Major losses for pipe upstream of pump (pipe A) only [L]

                                                                                                hm = Minor losses for entire pipe [L]

                                                                                                hmA = Minor losses for pipe upstream of pump (pipe A) only [L]

                                                                                                H = Total dynamic head [L] Also known as system head or head supplied by pumpHmax = Maximum head that pump can provide [L] It is the head when Q=0

                                                                                                k = Unit conversion factor = 1318 for English units = 085 for Metric unitsK = Sum of minor loss coefficients for entire pipe See table below for valuesKA = Sum of minor loss coefficients for pipe upstream of pump (pipe A) Same as Ka

                                                                                                L = Total pipe length [L]LA = Length of pipe upstream of pump (pipe A) [L] Same as La

                                                                                                NPSH = Net positive suction head [L] The calculation computes NPSHA (NPSH available)

                                                                                                Patm = Atmospheric (or barometric) pressure [P] Standard atmospheric pressure = 147 psi = 2992 inch

                                                                                                Hg = 760 mm Hg = 1 atm = 101325 Pa = 101 bar Note that your local atmospheric pressure is

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                                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                                program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                                to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                                location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                                Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                                zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                                reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                                V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                                reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                                of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                                Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                                this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                                Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                                available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                                and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

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                                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                                Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                                Material C Material C

                                                                                                Asbestos Cement 140 Copper 130-140

                                                                                                Brass 130-140 Galvanized iron 120

                                                                                                Brick sewer 100 Glass 140

                                                                                                Cast-Iron Lead 130-140

                                                                                                New unlined 130 Plastic 140-150

                                                                                                10 yr old 107-113 Steel

                                                                                                20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                                30 yr old 75-90 New unlined 140-150

                                                                                                40 yr old 64-83 Riveted 110

                                                                                                ConcreteConcrete-lined

                                                                                                Steel forms 140 Tin 130

                                                                                                Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                                Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                                Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                                Fitting K Fitting K

                                                                                                Valves Elbows

                                                                                                Globe fully open 10 Regular 90deg flanged 03

                                                                                                Angle fully open 2 Regular 90deg threaded 15

                                                                                                Gate fully open 015 Long radius 90deg flanged 02

                                                                                                Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                                Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                Gate 34 closed 17 Regular 45deg threaded 04

                                                                                                Swing check forward flow 2

                                                                                                Swing check backward flow infinity Tees

                                                                                                Line flow flanged 02

                                                                                                180deg return bends Line flow threaded 09

                                                                                                Flanged 02 Branch flow flanged 10

                                                                                                Threaded 15 Branch flow threaded 20

                                                                                                Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                                Square Connection 05 Square Connection 10

                                                                                                Rounded Connection 02 Rounded Connection 10

                                                                                                Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                                Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                                entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                                One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                                entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                                P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                                to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                                the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                                and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                                pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                                                                Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                                be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                                lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                                LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                                LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                bull

                                                                                                Trapezoidal Open Channel Design Calculation

                                                                                                Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                                Froude number Manning coefficient channel slope

                                                                                                To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                                Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                                LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                                Register to enable Calculate button

                                                                                                Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                                Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                                IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                                The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                                In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                                Variables [] indicates dimensions To calculation

                                                                                                A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                                divided by vertical distance

                                                                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                Oslash = Angle formed by S

                                                                                                Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                Material Manning n Material Manning n

                                                                                                Natural Streams Excavated Earth Channels

                                                                                                Clean and Straight 0030 Clean 0022

                                                                                                Major Rivers 0035 Gravelly 0025

                                                                                                Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                Stony Cobbles 0035

                                                                                                Metals Floodplains

                                                                                                Brass 0011 Pasture Farmland 0035

                                                                                                Cast Iron 0013 Light Brush 0050

                                                                                                Smooth Steel 0012 Heavy Brush 0075

                                                                                                Corrugated Metal 0022 Trees 015

                                                                                                Non-Metals

                                                                                                Glass 0010 Finished Concrete 0012

                                                                                                Clay Tile 0014 Unfinished Concrete 0014

                                                                                                Brickwork 0015 Gravel 0029

                                                                                                Asphalt 0016 Earth 0025

                                                                                                Masonry 0025 Planed Wood 0012

                                                                                                Unplaned Wood 0013

                                                                                                Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

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                                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

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                                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

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                                                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                                                Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                View the version 40 New Features List

                                                                                                Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

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                                                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                Learn More About AFT Impulse 40

                                                                                                Details Views Brochure Demo

                                                                                                copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                                • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                  • Local Disk
                                                                                                    • Circular Culvert Design Calculations Software Equations
                                                                                                        • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                          • Local Disk
                                                                                                            • Culvert Design Inlet and Outlet Control
                                                                                                                • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                  • Local Disk
                                                                                                                    • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                        • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                          • Local Disk
                                                                                                                            • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                  • Local Disk
                                                                                                                                    • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                        • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                          • Local Disk
                                                                                                                                            • Hydraulic Jump Calculation
                                                                                                                                                • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                  • Local Disk
                                                                                                                                                    • Manning Equation
                                                                                                                                                        • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                          • Local Disk
                                                                                                                                                            • Non-Circular Open Channel Geometry
                                                                                                                                                                • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                  • Local Disk
                                                                                                                                                                    • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                        • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                          • Local Disk
                                                                                                                                                                            • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                  • Local Disk
                                                                                                                                                                                    • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                        • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                          • Local Disk
                                                                                                                                                                                            • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                  • Local Disk
                                                                                                                                                                                                    • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                  different from standard atmospheric pressurePv = Vapor pressure of fluid [P] Expressed as an absolute pressure This value is built-in to the

                                                                                                  program as 2000 Nm2 (absolute) for water at 15oCP1 = Gage pressure at location 1 of the system [P] Location 1 could be the surface of a reservoir open

                                                                                                  to the atmosphere (thus P1=0) or the pressure in a supply main (same as a tank under pressure) or

                                                                                                  location 1 could simply be a location in a pipe upstream of the pumpP1-P3 = Pressure difference between locations 1 and 3 [P]

                                                                                                  Q = Flowrate [L3T] Also known as discharge or capacityQmax = Maximum flowrate on pump curve [L3T] Corresponds to point on pump curve where head is

                                                                                                  zeroS = Specific Weight of Water (ie weight density weight per unit volume) = 624 lbftsup3 for English units = 9800 Nmsup3 for Metric unitsV1 = Velocity of fluid at location 1 This is determined when you select a scenario If location 1 is a

                                                                                                  reservoir or main (Scenarios B C E and F) then V1 is automatically set to 0 because the velocity head

                                                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 1 is inside the suction side pipeline then V1 is automatically computed as QA

                                                                                                  V3 = Velocity of fluid at location 3 This is determined when you select a scenario If location 3 is a

                                                                                                  reservoir or main (Scenarios B D E and G) then V3 is automatically set to 0 because the velocity head

                                                                                                  of the fluid in the reservoir or main (or pressure tank) is much smaller than in the attached pipeline This is a standard assumption in fluid mechanics However if location 3 is inside your discharge side pipeline then V3 is automatically computed as QA

                                                                                                  Z1-Z2 = Elevation of location 1 minus elevation of pump [L] If the pump is above location 1 then enter

                                                                                                  this value as negativeZ1-Z3 = Elevation of location 1 minus elevation of location 3 [L]

                                                                                                  Common Questions Back to CalculationsWhat is net positive suction head It is the sum of the heads that push fluid into the pump less the suction side losses Most pumps have a minimum requirement for NPSH called NPSHR If the NPSH

                                                                                                  available by the piping system (NPSHA) is lower than NPSHR then the pump will not function properly

                                                                                                  and may overheatWhat is Driving Head DH is the sum of heads supplied by the pump elevation pressure and velocity differences between the inlet and outlet system boundaries DH is equivalent to the sum of minor and major lossesHow is Total dynamic head different than Driving head Total dynamic head H is the head that the pump must provide to overcome major losses minor losses and elevation pressure and velocity head differences between outlet and inlet H may be more or less than DH depending on whether the elevation pressure andor velocity head differences are beneficial or must be overcomeYour program is great What are its limitations Pipes must all have the same diameter The fluid must be water Our approximation for the pump curve may not be close enough to your actual pump

                                                                                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (5 of 8)12112007 40851 PM

                                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                  curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                                  Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                                  Material C Material C

                                                                                                  Asbestos Cement 140 Copper 130-140

                                                                                                  Brass 130-140 Galvanized iron 120

                                                                                                  Brick sewer 100 Glass 140

                                                                                                  Cast-Iron Lead 130-140

                                                                                                  New unlined 130 Plastic 140-150

                                                                                                  10 yr old 107-113 Steel

                                                                                                  20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                                  30 yr old 75-90 New unlined 140-150

                                                                                                  40 yr old 64-83 Riveted 110

                                                                                                  ConcreteConcrete-lined

                                                                                                  Steel forms 140 Tin 130

                                                                                                  Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                                  Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                                  Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                                  Fitting K Fitting K

                                                                                                  Valves Elbows

                                                                                                  Globe fully open 10 Regular 90deg flanged 03

                                                                                                  Angle fully open 2 Regular 90deg threaded 15

                                                                                                  Gate fully open 015 Long radius 90deg flanged 02

                                                                                                  Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                                  Gate 12 closed 21 Long radius 45deg threaded 02

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                                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                  Gate 34 closed 17 Regular 45deg threaded 04

                                                                                                  Swing check forward flow 2

                                                                                                  Swing check backward flow infinity Tees

                                                                                                  Line flow flanged 02

                                                                                                  180deg return bends Line flow threaded 09

                                                                                                  Flanged 02 Branch flow flanged 10

                                                                                                  Threaded 15 Branch flow threaded 20

                                                                                                  Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                                  Square Connection 05 Square Connection 10

                                                                                                  Rounded Connection 02 Rounded Connection 10

                                                                                                  Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                                  Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                                  entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                                  One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                                  entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                                  P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                                  to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                                  the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                                  and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                                  pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                                                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                                                                  Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                  result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                                  be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                                  lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                                  LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                                  LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                  fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                  bull

                                                                                                  Trapezoidal Open Channel Design Calculation

                                                                                                  Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                                  Froude number Manning coefficient channel slope

                                                                                                  To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                                  Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                                  LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                                  Register to enable Calculate button

                                                                                                  Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                                  Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                                  IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                  beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                                  The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                                  In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                                  Variables [] indicates dimensions To calculation

                                                                                                  A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                                  divided by vertical distance

                                                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                  Oslash = Angle formed by S

                                                                                                  Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                  Material Manning n Material Manning n

                                                                                                  Natural Streams Excavated Earth Channels

                                                                                                  Clean and Straight 0030 Clean 0022

                                                                                                  Major Rivers 0035 Gravelly 0025

                                                                                                  Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                  Stony Cobbles 0035

                                                                                                  Metals Floodplains

                                                                                                  Brass 0011 Pasture Farmland 0035

                                                                                                  Cast Iron 0013 Light Brush 0050

                                                                                                  Smooth Steel 0012 Heavy Brush 0075

                                                                                                  Corrugated Metal 0022 Trees 015

                                                                                                  Non-Metals

                                                                                                  Glass 0010 Finished Concrete 0012

                                                                                                  Clay Tile 0014 Unfinished Concrete 0014

                                                                                                  Brickwork 0015 Gravel 0029

                                                                                                  Asphalt 0016 Earth 0025

                                                                                                  Masonry 0025 Planed Wood 0012

                                                                                                  Unplaned Wood 0013

                                                                                                  Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                  Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                  Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                  Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                  The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                  cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                  simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                  The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                  References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                  a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                  c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                  e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                  Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                  Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                  French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                  Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                  d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                  Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                  b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                  7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                  Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

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                                                                                                  Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                  View the version 40 New Features List

                                                                                                  Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                  AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                  fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                  components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                  From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                  View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                  Learn More About AFT Impulse 40

                                                                                                  Details Views Brochure Demo

                                                                                                  copy 2001-2007 Applied Flow Technology All Rights Reserved

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                                                                                                  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                    • Local Disk
                                                                                                      • Circular Culvert Design Calculations Software Equations
                                                                                                          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                            • Local Disk
                                                                                                              • Culvert Design Inlet and Outlet Control
                                                                                                                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                    • Local Disk
                                                                                                                      • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                          • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                            • Local Disk
                                                                                                                              • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                  • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                    • Local Disk
                                                                                                                                      • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                            • Local Disk
                                                                                                                                              • Hydraulic Jump Calculation
                                                                                                                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                    • Local Disk
                                                                                                                                                      • Manning Equation
                                                                                                                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                            • Local Disk
                                                                                                                                                              • Non-Circular Open Channel Geometry
                                                                                                                                                                  • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                    • Local Disk
                                                                                                                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                            • Local Disk
                                                                                                                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                            • Local Disk
                                                                                                                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                    curve to give sufficiently accurate resultsDo you have more common questions and answers somewhere else on your website Yes see our Hazen Williams calculation without pump curvesWhere can I find additional information References

                                                                                                    Table of Hazen Williams Coefficients (C is unit-less) Back to CalculationsCompiled from References

                                                                                                    Material C Material C

                                                                                                    Asbestos Cement 140 Copper 130-140

                                                                                                    Brass 130-140 Galvanized iron 120

                                                                                                    Brick sewer 100 Glass 140

                                                                                                    Cast-Iron Lead 130-140

                                                                                                    New unlined 130 Plastic 140-150

                                                                                                    10 yr old 107-113 Steel

                                                                                                    20 yr old 89-100 Coal-tar enamel lined 145-150

                                                                                                    30 yr old 75-90 New unlined 140-150

                                                                                                    40 yr old 64-83 Riveted 110

                                                                                                    ConcreteConcrete-lined

                                                                                                    Steel forms 140 Tin 130

                                                                                                    Wooden forms 120 Vitrif clay (good condition) 110-140

                                                                                                    Centrifugally spun 135 Wood stave (avg condition) 120

                                                                                                    Table of Minor Loss Coefficients (K is unit-less) Back to CalculationsCompiled from References

                                                                                                    Fitting K Fitting K

                                                                                                    Valves Elbows

                                                                                                    Globe fully open 10 Regular 90deg flanged 03

                                                                                                    Angle fully open 2 Regular 90deg threaded 15

                                                                                                    Gate fully open 015 Long radius 90deg flanged 02

                                                                                                    Gate 14 closed 026 Long radius 90deg threaded 07

                                                                                                    Gate 12 closed 21 Long radius 45deg threaded 02

                                                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (6 of 8)12112007 40851 PM

                                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                    Gate 34 closed 17 Regular 45deg threaded 04

                                                                                                    Swing check forward flow 2

                                                                                                    Swing check backward flow infinity Tees

                                                                                                    Line flow flanged 02

                                                                                                    180deg return bends Line flow threaded 09

                                                                                                    Flanged 02 Branch flow flanged 10

                                                                                                    Threaded 15 Branch flow threaded 20

                                                                                                    Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                                    Square Connection 05 Square Connection 10

                                                                                                    Rounded Connection 02 Rounded Connection 10

                                                                                                    Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                                    Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                                    entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                                    One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                                    entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                                    P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                                    to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                                    the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                                    and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                                    pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                                                                    Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                    result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                                    be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                                    lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                                    LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                                    LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                    fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                    bull

                                                                                                    Trapezoidal Open Channel Design Calculation

                                                                                                    Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                                    Froude number Manning coefficient channel slope

                                                                                                    To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                                    Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                                    LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                                    Register to enable Calculate button

                                                                                                    Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                                    Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                                    IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                    beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                                    The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                                    In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                                    Variables [] indicates dimensions To calculation

                                                                                                    A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                                    divided by vertical distance

                                                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                    Oslash = Angle formed by S

                                                                                                    Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                    Material Manning n Material Manning n

                                                                                                    Natural Streams Excavated Earth Channels

                                                                                                    Clean and Straight 0030 Clean 0022

                                                                                                    Major Rivers 0035 Gravelly 0025

                                                                                                    Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                    Stony Cobbles 0035

                                                                                                    Metals Floodplains

                                                                                                    Brass 0011 Pasture Farmland 0035

                                                                                                    Cast Iron 0013 Light Brush 0050

                                                                                                    Smooth Steel 0012 Heavy Brush 0075

                                                                                                    Corrugated Metal 0022 Trees 015

                                                                                                    Non-Metals

                                                                                                    Glass 0010 Finished Concrete 0012

                                                                                                    Clay Tile 0014 Unfinished Concrete 0014

                                                                                                    Brickwork 0015 Gravel 0029

                                                                                                    Asphalt 0016 Earth 0025

                                                                                                    Masonry 0025 Planed Wood 0012

                                                                                                    Unplaned Wood 0013

                                                                                                    Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                    Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                    Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                    Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                    The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                    cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                    simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                    The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                    References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                    a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                    c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                    e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                    Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                    Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                    French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                    Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                    Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                    Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                    d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                    Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                    b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                    copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                    7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                    fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                    Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                    Products

                                                                                                    FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                    - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

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                                                                                                    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                    View the version 40 New Features List

                                                                                                    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                    Learn More About AFT Impulse 40

                                                                                                    Details Views Brochure Demo

                                                                                                    copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                      • Local Disk
                                                                                                        • Circular Culvert Design Calculations Software Equations
                                                                                                            • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                              • Local Disk
                                                                                                                • Culvert Design Inlet and Outlet Control
                                                                                                                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                      • Local Disk
                                                                                                                        • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                            • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                              • Local Disk
                                                                                                                                • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                    • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                      • Local Disk
                                                                                                                                        • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                            • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                              • Local Disk
                                                                                                                                                • Hydraulic Jump Calculation
                                                                                                                                                    • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                      • Local Disk
                                                                                                                                                        • Manning Equation
                                                                                                                                                            • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                              • Local Disk
                                                                                                                                                                • Non-Circular Open Channel Geometry
                                                                                                                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                      • Local Disk
                                                                                                                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                              • Local Disk
                                                                                                                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                      • Local Disk
                                                                                                                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                            • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                              • Local Disk
                                                                                                                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                      • Local Disk
                                                                                                                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                      Gate 34 closed 17 Regular 45deg threaded 04

                                                                                                      Swing check forward flow 2

                                                                                                      Swing check backward flow infinity Tees

                                                                                                      Line flow flanged 02

                                                                                                      180deg return bends Line flow threaded 09

                                                                                                      Flanged 02 Branch flow flanged 10

                                                                                                      Threaded 15 Branch flow threaded 20

                                                                                                      Pipe Entrance (Reservoir to Pipe) Pipe Exit (Pipe to Reservoir)

                                                                                                      Square Connection 05 Square Connection 10

                                                                                                      Rounded Connection 02 Rounded Connection 10

                                                                                                      Re-entrant (pipe juts into tank) 10 Re-entrant (pipe juts into tank) 10

                                                                                                      Error Messages Back to CalculationsAn input is lt 0 The following values must be entered as gt= 0 K and KA One or more of them was

                                                                                                      entered as lt0An input is lt= 0 The following values must be entered as positive Q V D L C Qmax Hmax LA

                                                                                                      One or more of them was entered as lt=0KA must be lt= K Minor loss coefficient for pipe A cannot exceed the minor loss coefficient for the

                                                                                                      entire pipe systemLA must be lt= L The length of pipe A cannot exceed the length of the entire pipe

                                                                                                      P1+Patm must be gt0 The sum of P1+Patm gives P1 in absolute pressure It is physically impossible

                                                                                                      to have an absolute pressure lt= 0 since that implies a complete vacuum at location 1Q must be lt= Qmax System flowrate cannot be entered as greater than the maximum flowrate that

                                                                                                      the pump can deliverTanks open so P1-P3=0 for B This message occurs if Scenario B (reservoir to reservoir) is selected

                                                                                                      and Solve for P1-P3 is selected Reservoirs are defined to be open to the atmosphere so they have a

                                                                                                      pressure difference of zero by default If you have tanks that are under pressure select Scenario E (main to main) insteadPump not needed H will be lt=0 The system characteristics that were entered result in a negative total dynamic head which means that a pump is not necessary to deliver the flow There are enough elevation pressure andor velocity head differences to overcome the major and minor losses without the need of a pump For this situation it would be better to run our Hazen-Williams calculation that doesnt incorporate a pump curveInfeasible Input DH will be lt=0 Driving head (the left hand side of the first equation shown above in Equations) must be positive in order for fluid to flow The system and pump characteristics entered

                                                                                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (7 of 8)12112007 40851 PM

                                                                                                      Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                      result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                                      be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                                      lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                                      LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                                      LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                      fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                      bull

                                                                                                      Trapezoidal Open Channel Design Calculation

                                                                                                      Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                                      Froude number Manning coefficient channel slope

                                                                                                      To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                                      Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                                      LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                                      Register to enable Calculate button

                                                                                                      Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                                      Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                                      IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                      beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                                      The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                                      In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                                      Variables [] indicates dimensions To calculation

                                                                                                      A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                                      divided by vertical distance

                                                                                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                      Oslash = Angle formed by S

                                                                                                      Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                      Material Manning n Material Manning n

                                                                                                      Natural Streams Excavated Earth Channels

                                                                                                      Clean and Straight 0030 Clean 0022

                                                                                                      Major Rivers 0035 Gravelly 0025

                                                                                                      Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                      Stony Cobbles 0035

                                                                                                      Metals Floodplains

                                                                                                      Brass 0011 Pasture Farmland 0035

                                                                                                      Cast Iron 0013 Light Brush 0050

                                                                                                      Smooth Steel 0012 Heavy Brush 0075

                                                                                                      Corrugated Metal 0022 Trees 015

                                                                                                      Non-Metals

                                                                                                      Glass 0010 Finished Concrete 0012

                                                                                                      Clay Tile 0014 Unfinished Concrete 0014

                                                                                                      Brickwork 0015 Gravel 0029

                                                                                                      Asphalt 0016 Earth 0025

                                                                                                      Masonry 0025 Planed Wood 0012

                                                                                                      Unplaned Wood 0013

                                                                                                      Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                      Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                      Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                      Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                      The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                      cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                      simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                      The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                      References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                      a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                      c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                      e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                      Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                      Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                      French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                      Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                      Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                      Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                      d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                      Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                      b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                      copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                      7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                      fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                      Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                      Products

                                                                                                      FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                      - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                      TitanUtilities

                                                                                                      SteamCalcEngineeringUtility SuiteChemPak

                                                                                                      home gt products gt impulse gt overview

                                                                                                      Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                      View the version 40 New Features List

                                                                                                      Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                      AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                      From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                      View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                      Learn More About AFT Impulse 40

                                                                                                      Details Views Brochure Demo

                                                                                                      copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                        • Local Disk
                                                                                                          • Circular Culvert Design Calculations Software Equations
                                                                                                              • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                • Local Disk
                                                                                                                  • Culvert Design Inlet and Outlet Control
                                                                                                                      • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                        • Local Disk
                                                                                                                          • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                              • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                • Local Disk
                                                                                                                                  • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                      • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                        • Local Disk
                                                                                                                                          • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                • Local Disk
                                                                                                                                                  • Hydraulic Jump Calculation
                                                                                                                                                      • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                        • Local Disk
                                                                                                                                                          • Manning Equation
                                                                                                                                                              • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                • Local Disk
                                                                                                                                                                  • Non-Circular Open Channel Geometry
                                                                                                                                                                      • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                        • Local Disk
                                                                                                                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                • Local Disk
                                                                                                                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                              • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                • Local Disk
                                                                                                                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                        Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation

                                                                                                        result in DH being lt= 0Infeasible Input (DH-hm)lt=0 The difference (DH-hm) is lt= 0 implying that major losses will also

                                                                                                        be lt=0 which is impossible for a flowing fluidInfeasible Input (DH-hf )lt0 The difference (DH-hf ) is lt 0 implying that minor losses will also be

                                                                                                        lt0 which is impossibleInfeasible input Driving head andor major losses are lt=0 or minor losses are lt 0

                                                                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)

                                                                                                        LMNO Engineering Research and Software Ltd7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890

                                                                                                        LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                        fileE|engineeringhydraulicsPressurized20Water20Calculation20uses20Hazen20Williams20equationhtm (8 of 8)12112007 40851 PM

                                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                        bull

                                                                                                        Trapezoidal Open Channel Design Calculation

                                                                                                        Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                                        Froude number Manning coefficient channel slope

                                                                                                        To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                                        Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                                        LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                                        Register to enable Calculate button

                                                                                                        Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                                        Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                                        IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                        beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                                        The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                                        In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                                        Variables [] indicates dimensions To calculation

                                                                                                        A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                                        divided by vertical distance

                                                                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                        Oslash = Angle formed by S

                                                                                                        Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                        Material Manning n Material Manning n

                                                                                                        Natural Streams Excavated Earth Channels

                                                                                                        Clean and Straight 0030 Clean 0022

                                                                                                        Major Rivers 0035 Gravelly 0025

                                                                                                        Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                        Stony Cobbles 0035

                                                                                                        Metals Floodplains

                                                                                                        Brass 0011 Pasture Farmland 0035

                                                                                                        Cast Iron 0013 Light Brush 0050

                                                                                                        Smooth Steel 0012 Heavy Brush 0075

                                                                                                        Corrugated Metal 0022 Trees 015

                                                                                                        Non-Metals

                                                                                                        Glass 0010 Finished Concrete 0012

                                                                                                        Clay Tile 0014 Unfinished Concrete 0014

                                                                                                        Brickwork 0015 Gravel 0029

                                                                                                        Asphalt 0016 Earth 0025

                                                                                                        Masonry 0025 Planed Wood 0012

                                                                                                        Unplaned Wood 0013

                                                                                                        Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                        Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                        Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                        Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                        The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                        cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                        simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                        The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                        References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                        a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                        c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                        e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                        Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                        Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                        French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                        Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                        Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                        Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                        d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                        Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                        b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                        copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                        7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                        fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                        Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                        Products

                                                                                                        FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                        - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                        TitanUtilities

                                                                                                        SteamCalcEngineeringUtility SuiteChemPak

                                                                                                        home gt products gt impulse gt overview

                                                                                                        Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                        View the version 40 New Features List

                                                                                                        Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                        AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                        Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                        components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                        From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                        View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                        Learn More About AFT Impulse 40

                                                                                                        Details Views Brochure Demo

                                                                                                        copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                        fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                        • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                          • Local Disk
                                                                                                            • Circular Culvert Design Calculations Software Equations
                                                                                                                • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                  • Local Disk
                                                                                                                    • Culvert Design Inlet and Outlet Control
                                                                                                                        • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                          • Local Disk
                                                                                                                            • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                  • Local Disk
                                                                                                                                    • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                        • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                          • Local Disk
                                                                                                                                            • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                  • Local Disk
                                                                                                                                                    • Hydraulic Jump Calculation
                                                                                                                                                        • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                          • Local Disk
                                                                                                                                                            • Manning Equation
                                                                                                                                                                • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                  • Local Disk
                                                                                                                                                                    • Non-Circular Open Channel Geometry
                                                                                                                                                                        • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                          • Local Disk
                                                                                                                                                                            • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                  • Local Disk
                                                                                                                                                                                    • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                        • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                          • Local Disk
                                                                                                                                                                                            • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                  • Local Disk
                                                                                                                                                                                                    • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                        • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                          • Local Disk
                                                                                                                                                                                                            • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                          bull

                                                                                                          Trapezoidal Open Channel Design Calculation

                                                                                                          Uses Manning Equation Compute velocity discharge depth top width bottom width area wetted perimeter hydraulic radius

                                                                                                          Froude number Manning coefficient channel slope

                                                                                                          To LMNO Engineering home page (more calculations) Gradually varied flow in trapezoidal channel

                                                                                                          Culvert Design using Inlet and Outlet Control Circular Culvert using Manning Equation Rectangular Channel Design Hydraulic Jump Unit Conversions

                                                                                                          LMNOLMNOengcom phone (USA) (740) 592-1890 Trouble printing

                                                                                                          Register to enable Calculate button

                                                                                                          Your browser does not support Java or Java is disabled in your browser Calculation should be here

                                                                                                          Links on this page Introduction Variables Manning n coefficients Error Messages References

                                                                                                          IntroductionMany natural and man-made channels are approximately trapezoidal This calculation uses the most commonly used equation for analyzing open channels - the Manning equation It is the equation

                                                                                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (1 of 5)12112007 40906 PM

                                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                          beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                                          The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                                          In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                                          Variables [] indicates dimensions To calculation

                                                                                                          A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                                          divided by vertical distance

                                                                                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                          Oslash = Angle formed by S

                                                                                                          Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                          Material Manning n Material Manning n

                                                                                                          Natural Streams Excavated Earth Channels

                                                                                                          Clean and Straight 0030 Clean 0022

                                                                                                          Major Rivers 0035 Gravelly 0025

                                                                                                          Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                          Stony Cobbles 0035

                                                                                                          Metals Floodplains

                                                                                                          Brass 0011 Pasture Farmland 0035

                                                                                                          Cast Iron 0013 Light Brush 0050

                                                                                                          Smooth Steel 0012 Heavy Brush 0075

                                                                                                          Corrugated Metal 0022 Trees 015

                                                                                                          Non-Metals

                                                                                                          Glass 0010 Finished Concrete 0012

                                                                                                          Clay Tile 0014 Unfinished Concrete 0014

                                                                                                          Brickwork 0015 Gravel 0029

                                                                                                          Asphalt 0016 Earth 0025

                                                                                                          Masonry 0025 Planed Wood 0012

                                                                                                          Unplaned Wood 0013

                                                                                                          Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                          Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                          Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                          Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                          The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                          cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                          simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                          The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                          References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                          a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                          c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                          e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                          Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                          Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                          French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                          Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                          Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                          Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                          d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                          Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                          b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                          copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                          7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                          fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                          Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                          Products

                                                                                                          FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                          - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                          TitanUtilities

                                                                                                          SteamCalcEngineeringUtility SuiteChemPak

                                                                                                          home gt products gt impulse gt overview

                                                                                                          Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                          View the version 40 New Features List

                                                                                                          Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                          AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                          fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                          Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                          components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                          From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                          View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                          Learn More About AFT Impulse 40

                                                                                                          Details Views Brochure Demo

                                                                                                          copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                          fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                          • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                            • Local Disk
                                                                                                              • Circular Culvert Design Calculations Software Equations
                                                                                                                  • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                    • Local Disk
                                                                                                                      • Culvert Design Inlet and Outlet Control
                                                                                                                          • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                            • Local Disk
                                                                                                                              • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                  • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                    • Local Disk
                                                                                                                                      • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                          • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                            • Local Disk
                                                                                                                                              • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                  • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                    • Local Disk
                                                                                                                                                      • Hydraulic Jump Calculation
                                                                                                                                                          • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                            • Local Disk
                                                                                                                                                              • Manning Equation
                                                                                                                                                                  • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                    • Local Disk
                                                                                                                                                                      • Non-Circular Open Channel Geometry
                                                                                                                                                                          • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                            • Local Disk
                                                                                                                                                                              • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                      • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                            • Local Disk
                                                                                                                                                                                              • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                  • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                                      • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                          • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                            • Local Disk
                                                                                                                                                                                                              • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                            beginning with V= above The Manning equation is best used for uniform steady state flows Uniform means that the cross-section geometry of the channel remains constant along the length of the channel and steady state means that the velocity discharge and depth do not change with time Though these assumptions are rarely ever strictly achieved in reality the Manning equation is still used to model most open channel flows where conditions are relatively steady and for reaches (portions of rivers) that have a reasonably constant cross-section for a long enough distance that the depth remains fairly constant

                                                                                                            The Manning equation is a semi-empirical equation Thus its units are inconsistent The factor k has units which allow the equation to be used properly Our calculation takes care of all the unit conversions for you and allows you to enter and compute variables in a wide variety of units

                                                                                                            In our calculation most of the combinations of inputs have analytic (closed form) solutions to compute the unknown variables however some require numerical solution Our numerical solutions utilize a cubic solver that finds roots of the equations with the result accurate generally to at least 8 significant digits All of our calculations utilize double precision Two depths and bottom widths are possible for certain combinations of entered values when Q T n and S or V T n and S are entered

                                                                                                            Variables [] indicates dimensions To calculation

                                                                                                            A = Flow cross-sectional area determined normal (perpendicular) to the bottom surface [L2]b = Channel bottom width [L]F = Froude number F is a non-dimensional parameter indicating the relative effect of inertial effects to gravity effects Flows with Flt1 are low velocity flows called subcritical Fgt1 are high velocity flows called supercritical Subcritical flows are controlled by downstream obstructions while supercritical flows are affected by upstream controls F=1 flows are called criticalg = acceleration due to gravity = 32174 fts2 = 98066 ms2 g is used in the equation for Froude numberk = unit conversion factor = 149 if English units = 10 if metric units Our software converts all inputs to SI units (meters and seconds) performs the computations using k=10 then converts the computed quantities to units specified by the usern = Manning coefficient n is a function of the channel material such as grass concrete earth etc Values for n can be found in the table of Mannings n coefficients shown belowP = Wetted perimeter [L] P is the contact length between the water and the channel bottom and sidesQ = Discharge or flowrate [L3T]R = Hydraulic radius of the flow cross-section [L]S = Slope of channel bottom or water surface [LL] Vertical distance divided by horizontal distanceT = Top width of the flowing water [L]V = Average velocity of the water [LT]y = Water depth measured normal (perpendicular) to the bottom of the channel [L] If the channel has a small slope (S) then using the vertical depth introduces only minimal errorz1 z2 = Side slopes of each bank of the channel These slopes are computed as horizontal distance

                                                                                                            divided by vertical distance

                                                                                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (2 of 5)12112007 40906 PM

                                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                            Oslash = Angle formed by S

                                                                                                            Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                            Material Manning n Material Manning n

                                                                                                            Natural Streams Excavated Earth Channels

                                                                                                            Clean and Straight 0030 Clean 0022

                                                                                                            Major Rivers 0035 Gravelly 0025

                                                                                                            Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                            Stony Cobbles 0035

                                                                                                            Metals Floodplains

                                                                                                            Brass 0011 Pasture Farmland 0035

                                                                                                            Cast Iron 0013 Light Brush 0050

                                                                                                            Smooth Steel 0012 Heavy Brush 0075

                                                                                                            Corrugated Metal 0022 Trees 015

                                                                                                            Non-Metals

                                                                                                            Glass 0010 Finished Concrete 0012

                                                                                                            Clay Tile 0014 Unfinished Concrete 0014

                                                                                                            Brickwork 0015 Gravel 0029

                                                                                                            Asphalt 0016 Earth 0025

                                                                                                            Masonry 0025 Planed Wood 0012

                                                                                                            Unplaned Wood 0013

                                                                                                            Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                            Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                            Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                            Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                            The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                            cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                            simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                            The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                            References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                            a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                            c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                            e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                            Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                            Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                            French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                            Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                            Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                            Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                            d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                            Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                            b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                            copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                            7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                            fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                            Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                            Products

                                                                                                            FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                            - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                            TitanUtilities

                                                                                                            SteamCalcEngineeringUtility SuiteChemPak

                                                                                                            home gt products gt impulse gt overview

                                                                                                            Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                            View the version 40 New Features List

                                                                                                            Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                            AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                            Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                            components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                            From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                            View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                            Learn More About AFT Impulse 40

                                                                                                            Details Views Brochure Demo

                                                                                                            copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                            fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                            • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                              • Local Disk
                                                                                                                • Circular Culvert Design Calculations Software Equations
                                                                                                                    • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                      • Local Disk
                                                                                                                        • Culvert Design Inlet and Outlet Control
                                                                                                                            • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                              • Local Disk
                                                                                                                                • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                    • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                      • Local Disk
                                                                                                                                        • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                            • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                              • Local Disk
                                                                                                                                                • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                    • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                      • Local Disk
                                                                                                                                                        • Hydraulic Jump Calculation
                                                                                                                                                            • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                              • Local Disk
                                                                                                                                                                • Manning Equation
                                                                                                                                                                    • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                      • Local Disk
                                                                                                                                                                        • Non-Circular Open Channel Geometry
                                                                                                                                                                            • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                              • Local Disk
                                                                                                                                                                                • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                      • Local Disk
                                                                                                                                                                                        • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                              • Local Disk
                                                                                                                                                                                                • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                    • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                      • Local Disk
                                                                                                                                                                                                        • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                            • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                              • Local Disk
                                                                                                                                                                                                                • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                              Oslash = Angle formed by S

                                                                                                              Mannings n Coefficients To calculationThe Mannings n coefficients were compiled from the references listed under Discussion and References and in the references at the bottom of this web page (note the footnotes which refer to specific references)

                                                                                                              Material Manning n Material Manning n

                                                                                                              Natural Streams Excavated Earth Channels

                                                                                                              Clean and Straight 0030 Clean 0022

                                                                                                              Major Rivers 0035 Gravelly 0025

                                                                                                              Sluggish with Deep Pools 0040 Weedy 0030

                                                                                                              Stony Cobbles 0035

                                                                                                              Metals Floodplains

                                                                                                              Brass 0011 Pasture Farmland 0035

                                                                                                              Cast Iron 0013 Light Brush 0050

                                                                                                              Smooth Steel 0012 Heavy Brush 0075

                                                                                                              Corrugated Metal 0022 Trees 015

                                                                                                              Non-Metals

                                                                                                              Glass 0010 Finished Concrete 0012

                                                                                                              Clay Tile 0014 Unfinished Concrete 0014

                                                                                                              Brickwork 0015 Gravel 0029

                                                                                                              Asphalt 0016 Earth 0025

                                                                                                              Masonry 0025 Planed Wood 0012

                                                                                                              Unplaned Wood 0013

                                                                                                              Corrugated Polyethylene (PE) with smooth inner walls ab 0009-0015

                                                                                                              Corrugated Polyethylene (PE) with corrugated inner walls c 0018-0025

                                                                                                              Polyvinyl Chloride (PVC) with smooth inner walls de 0009-0011

                                                                                                              Error Messages To calculationInvalid boxes checked This message is displayed if too many or too few variables are selected to be entered A problem cannot be over-stated or under-stated In all there are 30 combinations of inputs which are acceptable This message can be displayed to both registered and non-registered users

                                                                                                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (3 of 5)12112007 40906 PM

                                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                              The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                              cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                              simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                              The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                              References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                              a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                              c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                              e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                              Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                              Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                              French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                              Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                              Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                              Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                              d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                              Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                              b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                              copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                              7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                              fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                              Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                              Products

                                                                                                              FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                              - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                              TitanUtilities

                                                                                                              SteamCalcEngineeringUtility SuiteChemPak

                                                                                                              home gt products gt impulse gt overview

                                                                                                              Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                              View the version 40 New Features List

                                                                                                              Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                              AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                              Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                              components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                              From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                              View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                              Learn More About AFT Impulse 40

                                                                                                              Details Views Brochure Demo

                                                                                                              copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                              fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                              • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                                • Local Disk
                                                                                                                  • Circular Culvert Design Calculations Software Equations
                                                                                                                      • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                        • Local Disk
                                                                                                                          • Culvert Design Inlet and Outlet Control
                                                                                                                              • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                                • Local Disk
                                                                                                                                  • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                      • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                        • Local Disk
                                                                                                                                          • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                              • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                                • Local Disk
                                                                                                                                                  • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                      • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                        • Local Disk
                                                                                                                                                          • Hydraulic Jump Calculation
                                                                                                                                                              • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                                • Local Disk
                                                                                                                                                                  • Manning Equation
                                                                                                                                                                      • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                        • Local Disk
                                                                                                                                                                          • Non-Circular Open Channel Geometry
                                                                                                                                                                              • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                                • Local Disk
                                                                                                                                                                                  • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                          • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                                • Local Disk
                                                                                                                                                                                                  • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                      • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                                          • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                              • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                                • Local Disk
                                                                                                                                                                                                                  • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                                The following messages are displayed if an entered value lies outside the acceptable range for the variable These messages are only displayed when the Calculate button is clicked - for registered usersb must be gt 0 b must be 1e-9 to 10000 m n must be 1e-9 to 100 Q must be gt 0 Q must be 1e-9 to 1e9 m3s S must be 1e-9 to 1e9 T must be gt 0 T must be 1e-9 to 10000 m V must be gt 0 V must be 1e-9 to 1e9 ms y must be lt 0 y must be 1e-9 to 1e9 m z1 z2 must be gt=0 z1 z2

                                                                                                                cannot both be 0 Note that the channel cannot have both z1=0 and z2=0 However if you wish to

                                                                                                                simulate a rectangular channel you can set one of them to 00 and the other to a very small positive number such as 000001 Or you can use our rectangular open channel calculation Triangular channels can be modeled by setting the bottom width b to a very small positive number such as 0001 m or as low as 10-9 m

                                                                                                                The following messages are displayed if the values entered result in an infeasible situation For instance entering certain combinations of values for T Q n and S can result in an impossible flow situation indicated by a negative bottom width or negative depth These messages are only displayed when the Calculate button is clicked - for registered usersb will be lt 0 T will be gt 10000 m y will be lt 0 y will be lt= 0 y or b will be lt 0 The calculation uses an upper limit of 10000 m for top width

                                                                                                                References To calculationA further discussion of open channel flow Mannings equation and trapezoidal channel geometry can be found in these references and on our discussion page The Mannings n coefficients shown above are compiled from the references shown here The footnotes refer to specific values shown in the Manning n table above

                                                                                                                a Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1988

                                                                                                                c Barfuss Steven and J Paul Tullis Friction factor test on high density polyethylene pipe Hydraulics Report No 208 Utah Water Research Laboratory Utah State University Logan Utah 1994

                                                                                                                e Bishop RR and RW Jeppson Hydraulic characteristics of PVC sewer pipe in sanitary sewers Utah State University Logan Utah September 1975

                                                                                                                Chaudhry M H 1993 Open Channel Flow Prentice-Hall Inc

                                                                                                                Chow V T 1959 Open Channel Hydraulics McGraw-Hill Inc (the classic text)

                                                                                                                French R H 1985 Open Channel Hydraulics McGraw-Hill Book Co

                                                                                                                Mays L W editor 1999 Hydraulic design handbook McGraw-Hill Book Co

                                                                                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (4 of 5)12112007 40906 PM

                                                                                                                Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                                Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                                d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                                Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                                b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                                copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                                7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                                fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                                Products

                                                                                                                FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                                - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                                TitanUtilities

                                                                                                                SteamCalcEngineeringUtility SuiteChemPak

                                                                                                                home gt products gt impulse gt overview

                                                                                                                Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                                View the version 40 New Features List

                                                                                                                Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                                AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                                fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                                Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                                From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                                View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                                Learn More About AFT Impulse 40

                                                                                                                Details Views Brochure Demo

                                                                                                                copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                                fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                                • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                                  • Local Disk
                                                                                                                    • Circular Culvert Design Calculations Software Equations
                                                                                                                        • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                          • Local Disk
                                                                                                                            • Culvert Design Inlet and Outlet Control
                                                                                                                                • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                                  • Local Disk
                                                                                                                                    • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                        • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                          • Local Disk
                                                                                                                                            • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                                • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                                  • Local Disk
                                                                                                                                                    • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                        • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                          • Local Disk
                                                                                                                                                            • Hydraulic Jump Calculation
                                                                                                                                                                • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                                  • Local Disk
                                                                                                                                                                    • Manning Equation
                                                                                                                                                                        • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                          • Local Disk
                                                                                                                                                                            • Non-Circular Open Channel Geometry
                                                                                                                                                                                • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                                  • Local Disk
                                                                                                                                                                                    • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                        • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                          • Local Disk
                                                                                                                                                                                            • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                                • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                                  • Local Disk
                                                                                                                                                                                                    • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                        • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                          • Local Disk
                                                                                                                                                                                                            • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                                • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                                  • Local Disk
                                                                                                                                                                                                                    • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                  Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams

                                                                                                                  Munson BR D F Young and T H Okiishi 1998 Fundamentals of Fluid Mechanics John Wiley and Sons Inc 3ed

                                                                                                                  d Neale LC and RE Price Flow characteristics of PVC sewer pipe Journal of the Sanitary Engineering Division Div Proc 90SA3 ASCE pp 109-129 1964

                                                                                                                  Streeter V L E B Wylie and K W Bedford 1998 WCBMcGraw-Hill 9ed

                                                                                                                  b Tullis J Paul RK Watkins and S L Barfuss Innovative new drainage pipe Proceedings of the International Conference on Pipeline Design and Installation ASCE March 25-27 1990

                                                                                                                  copy 2000 LMNO Engineering Research and Software Ltd (All Rights Reserved)LMNO Engineering Research and Software Ltd

                                                                                                                  7860 Angel Ridge Rd Athens Ohio USA (740) 592-1890LMNOLMNOengcom httpwwwlmnoengcom

                                                                                                                  fileE|engineeringhydraulicsTrapezoidal20Openftware_20Manning20equation_20Rivers20streamshtm (5 of 5)12112007 40906 PM

                                                                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                  Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                                  Products

                                                                                                                  FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                                  - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                                  TitanUtilities

                                                                                                                  SteamCalcEngineeringUtility SuiteChemPak

                                                                                                                  home gt products gt impulse gt overview

                                                                                                                  Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                                  View the version 40 New Features List

                                                                                                                  Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                                  AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                                  fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                                  Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                  components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                                  From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                                  View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                                  Learn More About AFT Impulse 40

                                                                                                                  Details Views Brochure Demo

                                                                                                                  copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                                  fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                                  • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                                    • Local Disk
                                                                                                                      • Circular Culvert Design Calculations Software Equations
                                                                                                                          • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                            • Local Disk
                                                                                                                              • Culvert Design Inlet and Outlet Control
                                                                                                                                  • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                                    • Local Disk
                                                                                                                                      • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                          • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                            • Local Disk
                                                                                                                                              • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                                  • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                                    • Local Disk
                                                                                                                                                      • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                          • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                            • Local Disk
                                                                                                                                                              • Hydraulic Jump Calculation
                                                                                                                                                                  • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                                    • Local Disk
                                                                                                                                                                      • Manning Equation
                                                                                                                                                                          • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                            • Local Disk
                                                                                                                                                                              • Non-Circular Open Channel Geometry
                                                                                                                                                                                  • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                      • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                          • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                            • Local Disk
                                                                                                                                                                                              • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                                  • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                                      • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                          • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                            • Local Disk
                                                                                                                                                                                                              • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                                  • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                                    • Local Disk
                                                                                                                                                                                                                      • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                    Home | Products | Services | Customer Area | News | Training | Company | Contact Tuesday 11 December 2007

                                                                                                                    Products

                                                                                                                    FathomFathom ModulesArrowArrow ModulesMercuryImpulse

                                                                                                                    - Overview - Details - Brochure - Views - Latest Release - Annual Support - FAQ - Tips - Pricing - Ordering - Registration - Demo

                                                                                                                    TitanUtilities

                                                                                                                    SteamCalcEngineeringUtility SuiteChemPak

                                                                                                                    home gt products gt impulse gt overview

                                                                                                                    Waterhammer analysis tools of the past have been noted for being difficult to use and requiring extensive specialized knowledge As a result this critical aspect of piping system design and operation has often been overlooked But no longer Now AFT Impulsetrade offers the ease-of-use of a drag-and-drop interface and built-in waterhammer modeling expertise AFT Impulse helps you design and operate your systems with greater reliability and safety by avoiding the potentially catastrophic effects of waterhammer and other undesirable system transients

                                                                                                                    View the version 40 New Features List

                                                                                                                    Piping systems engineers typically do not have the time to become specialists in waterhammer modeling Now they donrsquot have to Now they can be equipped with the proper tools to design and analyze for waterhammer transients in liquid systems containing water petroleum and chemical products cryogens refrigerants and more Waterhammer specialists will find a no compromise tool capable of modeling a broad range of waterhammer events including transient cavitation and various surge suppression devices AFT Impulse provides a built-in library of fluids and fittings variable model configurations pump and control valve modeling and much more Scenario Manager raises the what-if potential of waterhammer modeling to a new level Multiple system configurations varying by any modeling parameter are easily managed within a single model file with a familiar hierarchical interface Changes in the base model are automatically inherited by alternate design cases

                                                                                                                    AFT Impulse incorporates a steady-state solver providing seamless transfer of initial conditions to the transient analysis The traditional Method of Characteristics are employed to solve the transient mass and momentum equations of pipe flow Modeling vapor cavitation and liquid column separation the effect of pressure surges due to vapor cavity collapse may be evaluated Modeling tools for a wide range of system

                                                                                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (1 of 2)12112007 40933 PM

                                                                                                                    Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                    components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                                    From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                                    View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                                    Learn More About AFT Impulse 40

                                                                                                                    Details Views Brochure Demo

                                                                                                                    copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                                    fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                                    • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                                      • Local Disk
                                                                                                                        • Circular Culvert Design Calculations Software Equations
                                                                                                                            • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                              • Local Disk
                                                                                                                                • Culvert Design Inlet and Outlet Control
                                                                                                                                    • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                                      • Local Disk
                                                                                                                                        • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                            • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                              • Local Disk
                                                                                                                                                • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                                    • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                                      • Local Disk
                                                                                                                                                        • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                            • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                              • Local Disk
                                                                                                                                                                • Hydraulic Jump Calculation
                                                                                                                                                                    • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                                      • Local Disk
                                                                                                                                                                        • Manning Equation
                                                                                                                                                                            • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                              • Local Disk
                                                                                                                                                                                • Non-Circular Open Channel Geometry
                                                                                                                                                                                    • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                                      • Local Disk
                                                                                                                                                                                        • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                            • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                              • Local Disk
                                                                                                                                                                                                • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                                    • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                                      • Local Disk
                                                                                                                                                                                                        • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                            • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                              • Local Disk
                                                                                                                                                                                                                • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                                    • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                                      • Local Disk
                                                                                                                                                                                                                        • Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                      Waterhammer surge analysis and transient analysis pipe flow modeling software

                                                                                                                      components and surge devices are included Transients can be initiated based on time or on events in the system For example a valve closure transient may be initiated when a specified pressure level is attained at a location In addition to time varying fluid dynamics AFT Impulse can calculate transient hydraulic forces on piping for use in calculating pipe stresses and even generate a CAESAR II force file for direct importation to this popular pipe stress analysis tool

                                                                                                                      From the powerful drag-and-drop model building features to the fully customizable output AFT Impulse is a powerful tool ready to tackle your most demanding design problems and with the release of version 40 AFT Impulse further expands you ability to analyze and design your piping systems dynamically

                                                                                                                      View a partial list of the many industry applications for AFT ImpulseView a partial list of the many system applications for AFT Impulse

                                                                                                                      Learn More About AFT Impulse 40

                                                                                                                      Details Views Brochure Demo

                                                                                                                      copy 2001-2007 Applied Flow Technology All Rights Reserved

                                                                                                                      fileE|engineeringhydraulicsWaterhammer20surgnt20analysis20pipe20flow20modeling20softwarehtm (2 of 2)12112007 40933 PM

                                                                                                                      • file____E__engineering_hydraulics_Circular20Culvert20Design20Calculations20-20Software20-20Equationspdf
                                                                                                                        • Local Disk
                                                                                                                          • Circular Culvert Design Calculations Software Equations
                                                                                                                              • file____E__engineering_hydraulics_Culvert20Design_20Inlet20and20Outlet20Controlpdf
                                                                                                                                • Local Disk
                                                                                                                                  • Culvert Design Inlet and Outlet Control
                                                                                                                                      • file____E__engineering_hydraulics_Design20of20Circular20Water20Pipes20using20Hazen20Williams20Equationpdf
                                                                                                                                        • Local Disk
                                                                                                                                          • Design of Circular Water Pipes using Hazen Williams Equation
                                                                                                                                              • file____E__engineering_hydraulics_DPlot20Graphing20Software20for20Scientists20and20Engineers20-20Home20Pagepdf
                                                                                                                                                • Local Disk
                                                                                                                                                  • DPlot Graphing Software for Scientists and Engineers - Home Page
                                                                                                                                                      • file____E__engineering_hydraulics_Gradually20Varied20Flow20Calculation_20Backwater20profilepdf
                                                                                                                                                        • Local Disk
                                                                                                                                                          • Gradually Varied Flow Calculation Backwater profile
                                                                                                                                                              • file____E__engineering_hydraulics_Hydraulic20Jump20Calculationpdf
                                                                                                                                                                • Local Disk
                                                                                                                                                                  • Hydraulic Jump Calculation
                                                                                                                                                                      • file____E__engineering_hydraulics_Manning20Equationpdf
                                                                                                                                                                        • Local Disk
                                                                                                                                                                          • Manning Equation
                                                                                                                                                                              • file____E__engineering_hydraulics_Non-Circular20Open20Channel20Geometrypdf
                                                                                                                                                                                • Local Disk
                                                                                                                                                                                  • Non-Circular Open Channel Geometry
                                                                                                                                                                                      • file____E__engineering_hydraulics_Pipe20Network20Calculator_20Hardy20Cross_20Darcy20Weisbach20or20Hazen20Williams20lossespdf
                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                          • Pipe Network Calculator Hardy Cross Darcy Weisbach or Hazen Williams losses
                                                                                                                                                                                              • file____E__engineering_hydraulics_Pressurized20Liquid20or20Gas20Pipes20with20Pump20Curve_20Darcy20Weisbach20(Moody20diagram)20friction20lossespdf
                                                                                                                                                                                                • Local Disk
                                                                                                                                                                                                  • Pressurized Liquid or Gas Pipes with Pump Curve Darcy Weisbach (Moody diagram) friction losses
                                                                                                                                                                                                      • file____E__engineering_hydraulics_Pressurized20Water20Pipes20with20Pump20Curve_20Calculation20uses20Hazen20Williams20equationpdf
                                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                                          • Pressurized Water Pipes with Pump Curve Calculation uses Hazen Williams equation
                                                                                                                                                                                                              • file____E__engineering_hydraulics_Trapezoidal20Open20Channel20Design20Calculations20Software_20Manning20equation_20Rivers20streamspdf
                                                                                                                                                                                                                • Local Disk
                                                                                                                                                                                                                  • Trapezoidal Open Channel Design Calculations Software Manning equation Rivers streams
                                                                                                                                                                                                                      • file____E__engineering_hydraulics_Waterhammer20surge20analysis20and20transient20analysis20pipe20flow20modeling20softwarepdf
                                                                                                                                                                                                                        • Local Disk
                                                                                                                                                                                                                          • Waterhammer surge analysis and transient analysis pipe flow modeling software

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