HM Laboratory Manual 2012

Hydraulic Machines Laboratory Manual

By Sreesh P S & Sailesh K SAINT GITS COLLEGE OF ENGINEERING, Pathamuttum, Kottayam 1

Fluid Mechanics & Hydraulic Machines Lab

This Lab is intended to make the students aware of the all the aspects which comes under the fluid

flow. The experiments include flow measurement, practical applications of the basic principles of fluid

mechanics and the study of major tools used. The hydraulics lab comprises of the performance tests of

pumps and load tests on turbine test rigs.

The Major equipments include:

Flow Apparatus

Venturimeter & Orificemeter

Orifice & Mouth piece

Pitot Tube

Reynold's Apparatus

Notches (V & Rectangular type)

Metacentric Height Apparatus

Bernouli's Theorem Apparatus

Losses Determination Apparatus

Test Rigs of Francis Turbine

Kaplan Turbine

Pelton Turbine

Centrifugal Pump

Reciprocating Pump

Jet Pump

Gear Pump

Submersible Pump

Hydraulic Ram



Hydraulic machines laboratory

SI. No

List of Experiments

1 Study Of Impact Of Jet On Vanes Of Different Types

2

Constant Head Test on Pelton Turbine

3

Constant Head Test on Francis Turbine

4

Constant Head Test on Kaplan Turbine

5 Performance test on Centrifugal pump

6

Performance test on Reciprocating pump

7

Constant Speed Test on Pelton Turbine

8

Constant Speed Test on Francis Turbine

9

Constant Speed Test on Kaplan Turbine

10

Performance test on Jet pump

11

Performance test on Submersible pump

12

Performance test on Gear pump

13

Performance test on Hydraulic ram



Introduction

Hydraulic machines lab is mainly intended to make an awareness of different hydraulic machines and their

operations. Here the theories learned in Hydraulic machines should be applied. Turbo machines are devices in which

energy is transferred either to, or from, a continuously flowing fluid by the dynamic action of moving blades on the runner

.the word turbo or turbines is of Latin origin and implies that which spins or whirls around.

Hydraulic machines include both power producing (Turbines) and power consuming (Pumps) devices.

Classification of Turbines as well as Pumps and general description of each type of turbine and pump is given in the

literature.

In modern day we make use of hydraulic machines for achieving our needs such as producing electricity, water

powered mills, pumping water etc. For each needs we require different kinds of machines.

In this lab the students are expected to learn the practical difficulties; precaution to be taken etc during the

performance of each experiment .Procedure for each experiment should be carefully followed as laid down in this manual.

Certain deviations in the equations from theory are made according to the test rig provided for easy understanding and

completion of each experiment.

In case each experiment the graphs are to be drawn as mentioned .In some cases standard graphs are given wherein

any deviations graphs obtained during the experiment are to be mentioned with proper reasons. Practical application of the

machines should be well understood.

Hydraulic Machines at a glance

Machine

Application

Remarks

Pelton Turbine

High head (Pallivasal,Idukki)

Impulse turbine with low specific speed range,

suitable for head above 300m

Francis Turbine

Medium head (Perigalkoothu,

Neriamangalam)

High efficiency, medium range of specific speed.

Head ranges between 50 m to 300m

Kaplan Turbine

Low head (Malampuzha)

High discharge, high specific speed, better part

load efficiency &suitable for head below 50 m.

Centrifugal Pump

Wide range of head and discharge.

Viscous or non viscous liquids

High efficiency, Suction head limited

Reciprocating pump

High delivery head, low discharge

(Metering pumps) Pumping water

in hilly regions

Low efficiency, Suction head limited. Discharge

increases head remains constant

Self priming pump

House hold application

Very low efficiency Suction head limited

Gear pump

Viscous liquids(Metering pumps)

Discharge increases head remains constant

Air lift pump

(Compressor

pump)

Bore well application, low

discharge, high head

No moving part in the well, maintenance free

Jet pump

Deep open well application

High suction lift, part of discharged water re circulate

through a nozzle fitted near to the foot valve

Submersible

centrifugal pump

Bore well and open well

No suction lift, sealed motor, motor

and pump assembly dipped in water



CLASSIFICATION OF FLUID MACHINES

1. Power Developing Machines Eg. Turbines

2. Power Absorbing Machines Eg. Pumps & Compressors

Turbines can be further classified according to the kind of energy.

1. Hydraulic Turbines Pressure Energy

2. Wind Turbines Kinetic Energy

3. Heat Turbines Thermal Energy

i) Steam Turbines

ii) Gas Turbines

Power Absorbing Machines can be further classified according to the kind of flow medium.

1. Pumps Liquid medium

2. Compressors Gas medium

i) Fans

ii) Blowers

iii) Turbo-Compressors







STUDY OF PELTON TURBINE

Pelton turbine is a tangential flow type impulse turbine. It is named after an American Engineer Lester.

A Pelton. It is well suited for high head operation where head is more than 250 meters.

The major components of the Pelton turbine identified from figure are penstock, nozzle, spear valve, runner

and casing. Penstock is the pipe line carrying water from the reservoir to the inlet of the turbine. This is

made of steel or reinforced concrete as it has to bear very high pressures due to the head of water and sudden

changes in flow rate. Runner consists of a circular disc with a number of buckets evenly placed around its

periphery. The runner is keyed to the main shaft of the turbine. The Pelton turbine buckets are double semi

ellipsoidal in shape. Each bucket is divided into two symmetrical cups with a sharp ridge known as splitter at

the centre. The jet of water impinges on the splitter, divides the jet into two equal portions each of which

after flowing round the smooth inner surface leaves at its outer edge. The buckets are so shaped that the angle

at the outlet tip varies from 10° to 20° so that the jet of water gets deflected through 160° to 170°. It avoids

deflected water striking at the back of the succeeding bucket causing braking effect.

The advantage of having double cup shaped bucket is that the axial thrusts neutralize each other being

equal and opposite and hence the bearings supporting the wheel shaft are not subjected to any axial

thrust. The back of bucket is so shaped that as it swings downwards into the jet no water is wasted by

splashing. At the tip of the bucket a notch is cut which prevents the jet striking the preceding bucket being

intercepted by next bucket very soon. It also avoids the deflection of water towards the centre of the wheel as

the bucket first meets the jet. For low heads the buckets are made by cast iron. But for higher heads they are

made of cast steel, bronze or stainless steel. Nozzle is a convergent tube, which converts all the available

pressure energy into kinetic energy and also directs the jet along the pitch circle of the runner. Spear valve

control the quantity of water striking the runner. The nozzle fitted at the end of penstock is provided with a

spear or needle having a streamlined head, which is fixed to the end of a rod. The spear may be operated by

a hand wheel in the case of small units or automatically by a governor in case of bigger units.

When the shaft of Pelton turbine is horizontal then not more than two jets are employed, but if the wheel is

mounted on a vertical shaft a large number of jets is possible. Casing of Pelton turbine is made of cast iron

or fabricated steel plates and has no hydraulic function to perform. It is provided only to prevent

splashing of water and lead splashed water to tail race and to set as safeguards against accidents.



The energy transfer from the fluid to the runner takes place because of impulse force. The Euler’s head

equation is

Schematic view of Pelton Turbine



Pelton Turbine Bucket



STUDY OF FRANCIS TURBINE

Francis turbine is a mixed flow reaction turbine named after James B. Francis. It is well suited for medium

head operations such as head ranging from about 60 to 250 meters.

The major parts identified from Figure of Francis turbine are penstock, spiral casing, stay vanes, guide

vanes, runner and draft tube. Penstock carries water form the reservoir to the turbine inlet. Water from the

penstock enters into the spiral casing, which completely surrounds the runner. The cross sectional, area of the

casing is made gradually decreasing to get a uniform velocity. Stay vanes are fixed vanes. They are half the

number of guide vanes. They resist the load imposed on them and transmit it to the foundation, through

the casing. Water coming from the stay vanes enters into the guide vanes. Guide vanes direct the water to

the runner vanes at the appropriate flow angle. The above described components guide the water into the

runner with minimum loss of energy. The runner of the Francis turbine consists of a series of curved vanes

evenly arranged around the annular space between two plates. The vanes are so shaped that water enter the

runner radially at the outer periphery and leave axially at the inner periphery. The reaction force on the

runner vanes due to the flow of water through the vane passage causes the runner to rotate. When flow is

passing through the runner static pressure gradually decreases. The force produced by the water is transmitted

through a shaft, which is keyed on to the runner. The water after passing through the runner flows to the

tailrace through a draft tube. Draft tube is a gradually increasing cross sectional area passage, which

connects the runner exit to the tailrace. It permits a negative suction head at the runner exit, thus making it

possible to install the turbine above the tailrace with out loss of head. It also regains a large portion of

kinetic energy rejected from the runner into the useful pressure energy. The energy transfer from the fluid to

the runner takes place because of reaction force.

The Euler’s head equation is

In reaction turbine, the energy transfer from the fluid to the runner takes place because of change in

tangential velocity and relative velocity. That is energy transfer is due to second and third terms (static

pressure) and the change in absolute velocity is zero. The second and third term causes reaction force.



Schematic view of Francis Turbine



STUDY OF KAPLAN TURBINE

Kaplan turbine is an axial flow reaction turbine, developed by an Austrian Engineer V. Kaplan. It is well

suited for low head operations such as head below 60 meters.

The main components of the Kaplan turbine are scroll casing, inlet guide vanes, and runner vanes. Draft tube

is placed at the exit of the runner. The water from the penstocks enters the casing. The casing has spiral

shape in which the cross-sectional area gradually decreases. (Hence it is also called scroll casing). The

casing completely surrounds the runner of the turbine. Due to the peculiar shape of the casing the water may

enter the runner at constant velocity throughout the circumference of the runner. The casing is made of

concrete, cast steel or plate steel.

The guide vanes are fixed between two rings in the form of a wheel known as guide-wheel. The guide

vanes have an aerofoil cross-section. This particular cross section allows water to pass over the vanes without

much velocity variation. Each guide vane can rotate about its pivot center, which is connected to the

regulating ring by mean of a link and a lever. The ring is connected to the regulating shaft by means of

regulating rods. By rotating the regulating shaft the guide vanes can be closed or opened allowing a variable

quantity of water. The guide vanes turn the incoming flow at an appropriate angle, to match the inlet

runner vane angle (zero incidence). The guide vanes are generally made of cast steel.

The runner of a Kaplan Turbine closely resembles a ship's propeller. Usually it has four or six blades and in

some exceptional cases even eight blades. The blades attached to a hub or boss cone are so shaped that

water flows axially through the runner. The turbine blades can be turned about their own axes so that, their

inlet (zero incidence) angle can be adjusted while the turbine is in motion. In Kaplan turbine, the incidence loss

at inlet of the guide vanes and runner vanes are very small because the runner vanes and guide vanes are

adjustable. Therefore, Kaplan turbine can operate over a wide range of load (discharge) without much

decrease of efficiency.

The draft tube is a divergent cross sectional area tube, which connects the runner exit to the tailrace.

The velocity at the exit of a reaction turbine is generally high which means it possesses large amount

of kinetic energy. The draft tube transforms kinetic energy into pressure energy while flowing through

this divergent cross sectional area tube. Therefore the effective head on the turbine is increasing. The

draft tube develops a vacuum pressure at the runner exit. The effective head acting on the turbine is the

pressure head at inlet plus the vacuum head at runner exit. It is also advantageous to construct the power

station above the tailrace without affecting the head acting on the machine



Schematic view of Kaplan Turbine



STUDY OF CENTRIFUGAL PUMP

Centrifugal pumps are rotodynamic type of pumps. The basic principle on which a centrifugal pump work is

that when a certain mass of liquid is made to rotate by any external force it is thrown away from the central

axis of rotation because a centrifugal head is impressed which enables the liquid to rise to higher level. The

main components of a centrifugal pump identified in figure are impeller, casing, suction pipe with foot valve

and strainer, delivery pipe and delivery valve.

Impeller is a circular wheel, which is provided with a series of curved vanes, imparts energy into the

fluid. The vanes can be curved backward (α<90°), radial (α = 90°) and forward (α > 90°) with out (open

impeller) or with shroud plates in back side (semi open impeller), shroud plates in back and frond side

(closed impeller). It is mounted on a shaft, which is coupled to an external source of energy, usually an electric

motor, which imparts the required energy to the impeller there by making it to rotate.

The impeller is surrounded by a spiral (volute) shaped casing. It is an airtight chamber. It is shaped in such a

way that the liquid can flow through a passage of gradually increasing area with constant velocity. Partial

conversion of velocity energy into pressure energy can take place in the casing. Moreover casing carries water

from the impeller to the delivery pipe. In large centrifugal pumps air vent is provided on the casing. This is used

to vent air at the time of priming.

The upper end of the suction pipe is connected to the casing at the center of the impeller. The lower end of

suction pipe is fitted with a foot valve and strainer. The strainer keeps away the debris. The foot valve is a

non return or one way type of valve which opens only in the upward direction.

Delivery pipe is connected at its lower end to the out let of the pump and it delivers the liquid to the

required height. A delivery valve is fitted near the outlet or the pump to control the flow from the pump to the

delivery pipe.

The first step in the working of centrifugal pump is priming. It is an operation by which suction pipe, casing

of the pump and portion of delivery pipe up to the delivery valve is filled with the liquid to be pumped, so

as to remove air gaps.

The necessity of priming in centrifugal pump is due to the fact that the centrifugal head generated by the

impeller is directly proportional to the density of liquid that is in contact with it.



Schematic view of Centrifugal Pump



After priming the delivery valve is kept closed (to reduce starting torque of the motor) and the electric motor

starts to rotate with the impeller. The rotation of the impeller imparts a centrifugal head to the liquid thereby

increasing pressure. The pressure at any point is directly proportional to the square of the angular velocity (ω2)

and the distance of the point from the axis of rotation (r2). Now the delivery valve is opened and the liquid is

allowed to flow in an outward radial direction. At the eye of the impeller a partial vacuum will be created. This

causes the liquid from the sump which is at atmospheric pressure to rise through the suction pipe to the eye of

rotation of impeller is utilised in lifting the liquid to the required height i.e. delivery pipe.



STUDY OF RECIPROCATING PUMP

The reciprocating pump is a positive displacement pump in which the liquid is sucked and then it is

displaced or pushed due to the thrust exerted on it by a moving member, which results in pumping liquid

to the required height. The discharge of liquid produced by these pumps completely depends on the speed of

the pump. Reciprocating pump generally operates at low speeds. So it is coupled to electric motor with belt

drives. Reciprocating pumps can be classified as Single acting or Double acting pump. If the liquid is in

contact with one side of the piston or plunger then it is known as single acting pump. Thus a single acting

pump has one suction pipe and one delivery pipe. In one complete revolution of the crank there are only two

strokes - one suction and one delivery stroke. On the other hand if the liquid is in contact with both the sides of

the piston or plunger it is known as double acting pump. A double acting pump has two suction and two

delivery pipes. So during each stroke when suction taken place on one side of the piston, the other side delivers

the liquid. In this way in the case of a double acting pump in one complete revolution of the crank there are

two suction strokes and two delivery strokes. Reciprocating pump is well suited for low discharge and high

delivery head applications.

The main parts of reciprocating pumps are cylinder, piston or plunger, suction and delivery valves, suction

pipe with strainer, delivery pipe and air vessels on both suction and delivery pipes close to cylinder. The

cylinder is the chamber where water is admitted. Suction and delivery pipes are connected to the cylinder. A

piston or plunger reciprocates in side the cylinder. Piston or plunger is the part that reciprocates inside the

cylinder. The difference between piston and plunger is that piston length is much shorter that its stroke whereas

the length of the plunger is more than its stroke. Another distinguishing feature is that in case of piston, the

packing is laid on the rim of piston for a light seal. But when a plunger is used the packing is in a stuffing box

located at the end of the cylinder to provide a tight seal. The piston is connected to the crank through a

piston rod and connecting rod. Piston rod and connecting rod are joined together by means of cross head.

But in the case of a plunger pump the plunger is directly connected to the crank by means of the connecting

rod. A prime mover (either electric motor or diesel engine) supplies power to the pump and thereby rotates

the crank. The rotating motion of the crank is converted to reciprocating motion of either piston or

plunger by means of a connecting rod and crankshaft. A suction pipe is a connecting passage between



the source of fluid (water) and the cylinder. The suction pipe is provided with a non return or one way valve

called suction valve. The function of the valve is it admit water in one direction only. Then the suction valve

allows the liquid to only enter the cylinder. The delivery pipe collect the liquid discharged from the cylinder

and carries to the delivery tank. Similar to a suction pipe, delivery pipe is also provided with a one way valve

called delivery valve. The delivery valve allows the liquid to flow from the cylinder to the delivery pipe.

Air vessels are provided on both suction and delivery side close to the suction valve and the delivery valve.

An air vessel is a closed chamber containing compressed air on the top portion and liquid at the bottom

of the chamber. At the base of the chamber there is an opening through which the liquid may flow into the

vessel or out from the vessel. When the liquid enter the air vessel, the air gets compressed further and when

liquid flows out of the vessel, the air will expand in the chamber.

An air vessel serves continuous supply of liquid at uniform rate, save a considerable amount of work

in overcoming the frictional resistance in the suction and delivery pipes, run the pump at a high speed

without separation.

As the crank is rotated at uniform speed by a driving engine or motor, the piston or plunger moves to and fro in

the cylinder. When the crank rotates from θ = 00 to θ =180

0 the piston or plunger which is initially at its extreme

left position (that is it is completely inside the cylinder) moves to its extreme right position (that is it

moves outwards from the cylinder). During the outward movement of the piston or plunger a partial vacuum

(pressure below atmospheric) is created in the cylinder. This enables the atmospheric pressure acting on the

liquid surface in the well or sump below to force the liquid up in the suction pipe. This liquid opens the suction

valve and enters the cylinder. Since during this operation of the pump the liquid is sucked from below it is

known as suction stroke. Thus at the end of the suction stroke the piston or plunger is at its extreme right

position, the crank is at θ =1800, the cylinder is full of liquid. When the crank rotates from θ =180

0 to 360

0 the

piston or plunger moves inwardly from its extreme right position towards left. The inward movements of

the piston or plunger causes the pressure of the liquid in the cylinder to rise above atmospheric. Due to this

suction valve closes and the delivery valve opens. The liquid is then force opens the delivery valve and

flows up through the delivery pipe and rise to the required height. Since during this operation of the pump

the liquid is actually delivered to the required height it is known as delivery stroke. At the end of the

delivery stroke the piston or plunger is at extreme left position, the crank is at θ = 00or 360

0 (i.e. at its inner

dead center) so that it has completed one full revolution. Now both the suction and delivery valves will



be closed. The next cycle will be repeated as the crank rotates.

During the first half of the suction stroke the piston moves with acceleration. So the velocity of water in the

suction pipe must be more than mean velocity. Hence the discharge of water entering the cylinder will be

more than the mean discharge. This excess quantity of water will be supplied from the air vessel to the

cylinder. Thereby the velocity in the suction pipe below the air vessel is made equal to mean velocity of flow.

During the second half of the suction stroke the piston moves with retardation. Hence velocity of flow in the

suction pipe is less than the mean velocity of flow. Thus the discharge entering the cylinder will be less than

the mean discharge. But the velocity of liquid in the suction pipe will be made equal to mean velocity and the

excess water flowing in suction pipe will be stored in the air vessel. This will be supplied during the first half

of the next suction stroke

Similarly an air vessel may be provided to the delivery pipe also. During the first half of the delivery stroke the

piston moves with acceleration and forces water into the delivery pipe with a velocity more than the mean

velocity. The quantity of water in excess of mean discharge will flow into the air vessel. This will

compress the air inside the vessel. During the second half of the delivery strike the piston moves with

retardation and velocity of water in the delivery pipe will be less than the mean velocity. The water already

stored into the air vessel will start flowing into the delivery pipe. Then the velocity of flow in the delivery pipe

is beyond the point to which air vessel is filled will become equal to the mean velocity. Hence the rate of flow

of water in the delivery pipe will be uniform.



Schematic view of Reciprocating Pump



1. CONSTANT HEAD TEST ON PELTON TURBINE

Aim:

To conduct load test on the given pelton turbine at constant head and to plot the main characteristic curves

Specifications

Head=46m

Discharge=800 lpm

RPM=750

Output power= 1 KW

Description:

Pelton Turbine is an impulse turbine that uses water available at high heads (pressure) for generation of

electricity. All the available potential energy of water is converted into kinetic energy by a nozzle

arrangement. The water leaves the nozzle as a jet and strikes the buckets of the Pelton wheel runner. These

buckets are in the shape of double cup-, joined at the middle portion in a knife edge. The jet strikes the knife

edge of the buckets with least resistance and shock and glides along the path of the cup, deflecting through

an angle of 160 to 170 deg. This deflection of water causes a change in momentum of the water jet and

hence an impulsive force is supplied to the buckets. As a result, the runner attached to the buckets moves,

rotating the shaft. The specific speed of the Pelton wheel varies from 10 to 100,

In the test rig the Pelton wheel is supplied with water under high pressure by a centrifugal pump. The water

flows through an orifice meter to the Pelton wheel. A gate valve is used to control the flow rate to the

turbine. The orifice meter with pressure gauges connected to it is used to determine the flow rate of water in

the pipe. The nozzle opening can be decreased or increased by operating the spear wheel at the entrance side

of turbine.

The Turbine is loaded by applying dead weights on the brake drum. This is done by placing, the weights on

the weight hanger. The inlet head is read from the pressure gauge. The speed of the turbine is measured with

a tachometer

Experimental -Procedure:

1) Calculate the maximum load that can be used

2) Close the delivery gate valve completely and start the pump.

3) Add minimum load, to the weight hanger of the brake drum – say1 kgf.

4) Open the gate valve while monitoring the inlet pressure to the turbine. Set it for the design

value of 3 kg/sq.cm.



5) Open the cooling water valve for cooling the brake drum.

6) Measure the turbine rpm with tachometer.

7) Note the pressure gauge reading at the turbine inlet.

8) Note the orifice meter pressure gauge readings, P1 and P2.

9) Add additional weights and repeat the experiments for other loads.

(For constant speed tests, the main valve has to be adjusted to reduce or increase the inlet head to

the turbine for varying loads).

Warning:

1. Always operate the turbine with a load. Since the runaway speed of the turbine is high, running the

turbine without any load will lead to excess vibrations and noise.

2. Provide cooling water for the brake drum when it is loaded. Absence of cooling water will cause brake

drum heating and even charring of the rope under extreme conditions. Amount of cooling water must be

controlled to avoid excessive spillage and splashing.

3. The motor is provided with DOL starter to trip under overload, low voltage, uneven phase supply

conditions, If the motor trips, check for voltage conditions. Also, do not run the supply pump at fully open

valve conditions as this is an overload condition for the pump.

Calculations:

I. To determine discharge:

Orifice meter line pressure gauge readings = P1 kg/sq. cm

Orifice meter throat pressure gauge reading = P2 kg/sq.cm

Pressure difference dH = (P I -P2) × 10 m of water

Orifice meter equation Q = Cd×a1×a2× (2×9.81 x dH) 0.5

\ (a12-a2

2)

0.5 m

3/sec

= Cd×A×B2× ((2×9.81 × dH)

/(1-B

4 ))

0.5

= 0.00204 (dH)

0.5

Note: where,Cd - Orifice meter discharge coefficient-0.61 – A=Inlet Area=3.14×d12/4 , Inlet dia, d1- 50mm,

throat dia ratio, B = 0.6

II. To determine Head

Turbine Pressure gauge reading = P kg/sq.cm

Total Head H = P×10 m of water



III. Input to the turbine:

Input Power= ρgQH /1000 kW =9.81 QH kW

IV. Turbine Out put power:

Brake drum diameter = 0.20m.

Rope diameter = 0.015m.

Equivalent drum diameter(D) = 0.215m

Hanger weight - To = 1 kgf

Weight added =T1 kgf

Spring Load = T2 kgf

Resultant load - T = (T0+T1-T2) kgf

Speed of the turbine = N RPM

Output Power =Torque(τ )×Angular Velocity(

= (T× g×D/2) × [(2×π×N)/60] Watts

={(T× g×D/2) × [(2×π×N)/60]}/1000 kW

Turbine Efficiency= Output power/Input power x 100

Sample Calculations (set no: )

Orifice meter Constant =0.00204

Brake drum diameter =0.2m

Rope diameter =0.015 m

Equivalent drum diameter (D)=0.215m

Input total head=10xP m of water

Orifice meter head differenced dH =10 (P1-P2) m of water

Discharge, Q=0.00204 (dH) 0.5

cu.m/sec

Input Power=9.81 x Q x H kW

Weight of empty hanger T0 = 1 kgf

Brake drum net load (T)= (T0+T1-T2) Kgf

Turbineoutput ={(T× g×D/2) × [(2×π×N)/60]}/1000 kW

Efficiency= Output/Input x 100 %



Tabular column - _0 t -It P

Sl

No

Inlet

Press.

P kg/

sq.cm

Total

head,

H m

of

water

Orifice meter Press.

Gauge readings

Discharge,

Q

cu.m/sec

Speed

N

rpm

Wt.on

hanger

T1 kg

Spring

balance

T2 kg

Net Wt.

T k g

Output

K W

Input

K W

Efficiency

%

P1

kg/sq.cm

P2

kg/sq

.cm

dH

m of

water

Where P is output power, η is Efficiency, Q is discharge& N is speeding rpm





2. CONSTANT HEAD TEST ON FRANCIS TURBINE

Aim:

To conduct load test on the given Francis turbine at constant head and to plot the main characteristic curves

Specifications

Head=18 m

Discharge=1900 lpm

RPM=1500

Output power=3.7 KW

Description:

Francis turbine is a reaction type hydraulic turbine, used in dams and reservoirs of medium height to convert

hydraulic energy into mechanical and electrical energy. Francis Turbine is a radial inward flow reaction

turbine. This has the advantage 6f centrifugal forces acting against the flow, thus reducing the tendency, of

the turbine to over speed. Francis Turbines are best suited for medium heads, say 40m. to 300m. The specific

speed ranges from 25 to 300.

The turbine test rig consists of a 3.72 KW (5 H-P) turbine supplied with water from a suitable 15 HP

centrifugal pump through suitable pipelines, a gate valve, and a flow measuring venturimeter. The turbine

consists of a cast iron body with a volute casing and a gunmetal runner consisting of two shrouds with

aerofoil shaped curved vanes in between, the runner is surrounded by a set of adjustable gunmetal guide

vanes. These vanes can be rotated about their axis by a hand wheel. Their position is indicated by a pair of

dummy guide vanes fixed on the outside of the turbine casing. At the outlet, a draft tube is provided to

increase the net head across the turbine. The runner is attached to the output shaft with a brake drum to

absorb the energy produced.

Water under pressure from pump enters through the guide vanes into the runner. While passing through the

spiral casing and guide vanes, a portion of the pressure energy is converted into velocity energy, Water thus

enters the runner at a high velocity and as it passes through the runner vanes, the remaining pressure energy

is converted into kinetic energy. Due to the curvature of the vanes, the kinetic energy is transformed into the

mechanical energy i.e., the water head is converted into mechanical energy and hence the runner rotates. The

water from the runner is then discharged into the tailrace. The discharge through the runner can be regulated

also by operating the guide vanes.

The flow through the pipe lines into the turbine is measured with the venturimeter fitted in the pipe

line. The Venturimeter is provided with a set of pressure gauges. The net pressure difference across the

turbine inlet and Cutlet is measured with a pressure gauge and a vacuum gauge. The turbine output torque is

determined with a rope brake drum dynamometer. A tachometer is used to measure the rpm.



Experimental Procedure:

1) Calculate the maximum load that can be used.

2) Keep the guide vanes at required opening (say 3/8th).

3) Prime the pump if necessary.

4) Close the main gate valve and start the pump.

5) Open the gate valve for required discharge after the pump motor switches from star to delta mode.

6) Load the turbine by adding weights in the weight hanger. Open the brake drum cooling water gate

valve for cooling the brake drum.


8) Note the pressure gauge and vacuum gauge readings.

9) Note the venturimeter pressure gauge readings.

10) Repeat the experiments for other loads.

11) For constant speed tests, the main sluice valve has to be adjusted to vary the inlet head and discharge

for varying loads (at a given guide vane opening position).

12) The experiment can be repeated for other guide vane positions.

Warning

1) Do not start the motor without priming the pump.

2) Do not start the motor without closing the delivery valve completely.

3) Only after the starter has changed to delta mode from the star mode (this is indicated by the jump in

the motor speed), the delivery valve should be opened.

4) Starter tripping indicates motor overload and this will occur if the pump discharge is above its normal

range. When the motor is restarted, ensure that the flow rate is maintained within the normal

range.As the motor is designed to run at 400-440 Volts, starter will also trip when the supply voltage

is low - less than about 380 Volts. In such case, operate the motor pump set at reduced flow rates -

the turbine output will be correspondingly lower than the design value of 5HP.

NOTE: Do not operate the motor at very low voltages of 3-50 Volts and below as this will draw

excessive current, leading to motor coil burn-out.

5) The 15HP mono block motor is provided with a cooling fan and consists of class A insulating

materials (temperature limit - 105 deg. Q. Temperature rise of the motor during its operation is

normal and at lower supply voltages, the rise will be higher. Immediately after shut-off, due to

absence of cooling the motor temperature will rise higher than the temperature during operation. This

is normal and does not indicate any malfunction.



Equations &Calculations:

I. To determine discharge.

Venturimeter line pressure gauge reading = P1 kg/sq. cm

Venturimeter throat pressure gauge reading = P2 kg/sq.cm

Pressure difference dH = (P I -P2)x 10m of water

Orifice meter equation Q = Cd×a1×a2× (2×9.81×dH) 0.5

\ (a12-a2

2) 0.5

m3/sec

= CdxAxB2x ((2x9.81xdH)/ (1-B

4))

0.5 m

3/sec

=0.0131(dH) 0.5

m3/sec

Note: where, Venturimeter inlet dia D= 100mm, throat dia ratio B = 0.6 Cd - Venturimeter discharge

coefficient - 0.98, A - inlet area = (3.14xD2)/4

II. To determine inlet head of water:

Turbine Pressure gauge reading = P kgf/sq.cm

Turbine vacuum gauge reading = V mm of Hg

Total Head, H = 10 (P+V/760) m of water


Input Power = ρgQH /1000 kW =9.81 QH kW

IV. Turbine Output:



Equivalent drum diameter(D) = 0.315m

Hanger weight -T0 = 1Kgf.

Weight = T1 Kgf.

Spring Load = T2 Kgf,

Resultant load - T = (T1 - T2+ T0) kg

Speed of the turbine =N RPM

Output Power =Torque(τ )×Angular Velocity(

= (T× g×D/2) × [(2×π×N)/60] Watts

={(T× g×D/2) × [(2×π×N)/60]}/1000 kW

Turbine efficiency = Output\Input

Sample Calculations:

Venturimeter Constant =0.0131 Input total head H = 10(P+V/760) m of water

Brake drum diameter = 0.3m Venturimeter head diff,dH = 10 (P1 -P2) m of water

Rope diameter = 0.015m discharge= 0.0131(dH) 0.5

cu.m/sec

Equivalent drum dia, D = 0.315m Input Power, I/P= 9.8lxQxH kW

Weight of empty hanger T0 = 1 Kgf Brake drum net wt. T= (T0+T I -T2) Kg

Turbine output,O/P={(T× g×D/2) × [(2×π×N)/60]}/1000 kW

Efficiency= Output/Input x100%



Tabular column

Sl.

No

Inlet.

Press.

P

Kg/sq.

cm

Outlet

Vac.

V

mm of

Hg

Total

Head

H

m of

water

Venturimeter Press.

Gauge readings

Flow

rate

Q

cu.m/

sec

Speed

N

rpm

Wt. on

Hanger

T1 Kg

Spring

balance

T2 Kg

Net

Wt

T

Kg

Output

O

kW

Input

I kW

Efficiency

%

P1

Kg/sq.

cm

P2

Kg/sq.

cm

dH in

m of

water




3. CONSTANT HEAD TEST ON KAPLAN TURBINE

Aim:

To conduct load test on the given Kaplan turbine at constant head and to plot the main characteristic curves

Specifications

Head=7 m

Discharge=5000 lpm

RPM=1500

Output power=1 KW

Description:

Kaplan turbine is an axial flow reaction turbine used in dams and reservoirs of low height to convert

hydraulic energy into mechanical and electrical energy. They are best suited for low heads say from 10 m to

50 m. The specific speed ranges from 200 to 1000.

The test rig consists of an I KW (1.34 HP) Kaplan turbine supplied with water from a suitable 5 HP pump

through pipelines, a valve, and a flow measuring venturimeter. The turbine consists of a cast iron body with

a volute casing, an axial flow gunmetal runner, a ring of adjustable guide vanes and a draft tube. The runner

consists of three vanes of aerofoil section. The guide vanes can be rotated about their axis by means of hand

wheel. A rope brake drum is mounted on the turbine shaft to absorb the power developed. Suitable dead

weights and a hanger arrangement, a spring balance and cooling water arrangement is provided for the brake

drum.

Water under pressure from pump enters through the volute casing and the guide vanes into the runner. While

passing through the spiral casing and guide vanes, a portion of the pressure energy (potential energy) is

converted into velocity energy (kinetic energy). Water thus enters the runner at a high velocity and as it

passes through the runner vanes, the remaining potential energy is converted into kinetic energy. Due to the

curvature of the vanes, the kinetic energy is transformed into the mechanical energy i.e., the water head is

converted into mechanical energy and hence the runner rotates. The water from the runner is then discharged

into the draft tube.

The flow through the pipe lines into the turbine is measured with the venturimeter fitted in the pipe line.

Two pressure gauges are provided to measure the pressure difference across the venturimeter. The net

pressure difference across the turbine-inlet and exit is with a pressure gauge and vacuum gauge. The turbine

output torque is determined with a rope brake drum .A tachometer is used measure the rpm.


1) Calculate the maximum load that can be used

2) Add minimum load to the weight banger of the brake drum - say l kg.

3) Close the main gate valve and start the pump.



4) Open the gate valve while monitoring the inlet pressure to the turbine.

5) Open the cooling water valve for cooling the brake drum.


7) Note the pressure gauge and vacuum gauge readings at the turbine inlet and outlet.

8) Note the venturimeter pressure gauge readings, P1and P2.

9) Add additional weights and repeat the experiments for other loads.

10) For constant speed tests, the main valve has to be adjusted to reduce or increase the inlet head to the

turbine for varying loads.

Warning:

1. Always operate the turbine with a load. Since the runaway speed of the turbine is about 4000 rpm,

running the turbine without any load will lead to excess vibrations an noise.

2. Provide cooling water for the brake drum when it is loaded. Absence of cooling water will cause

brake drum heating and even charring of the rope under extreme conditions.

3. Amount of cooling water must be controlled to avoid excessive spillage and splashing.

4. The motor is provided with DOL starter to trip under overload, low voltage, and uneven phase

supply. If the motor trips, check for voltage conditions. Also, do not run the supply pump at fully

open valve conditions as this is an overload condition for the pump.

Calculations:

I. To determine discharge.

Venturimeter line pressure gauge reading = P1 kg/sq. cm

Venturimeter throat pressure gauge reading = P2 kg/sq.cm

Pressure difference dH = (P I -P2)x 10m of water

Orifice meter equation Q = Cdxa1xa2x (2x9.81 x dH) 0.5

\ (a12-a2

2) 0.5

m3/sec

= CdxAxB2x ((2x9.81xdH)/ (1-B

4))

0.5 m

3/sec

Note: where, Venturimeter inlet dia D= 100mm, throat dia ratio B = 0.6 Cd - venturimeter discharge

coefficient - 0.98, A - inlet area)(3.14xD2)/4

II. To determine inlet head of water:

Turbine Pressure gauge reading = P kg/sq.cm

Turbine vacuum gauge reading = V mm of Hg

Total Head H = 10 (P+V/760) m of water




Input Power =ρgQH\736 = 1000 QH\75 HP

= ρgQH /1000 kW =9.81 QH kW

IV. Turbine Output:



Equivalent drum diameter = 0.215m

Hanger weight - T0 = 1Kg.

Weight = T1 Kg.

Spring Load = T2 Kg,

Resultant load - T = (TI - T2+ T0) kg

Speed of the turbine = N RPM

Output Power = (2×π×N×τ)/ (75x60) HP = (3.14xDxNxT)/(75x60) HP

= (2×π×N×τ)/ (1000x60) kW

= (3.14×D×N×T×g) / (1000 ×60) kW

= (3.14×D×N×T) / (102×60) kW

Turbine efficiency = output\input


Venturimeter Constant =0.0131 Input total head H = 10(P+V/760) m of water

Brake drum dia = 0.2m Venturimeter head difference dH= 10(PI-P2) m of water

Rope dia = 0.015m Discharge Q = 0.0 131 (dH)0.5

cu.m/sec

Equivalent drum dia = 0.215m Input Power I = 9.8lxQxH kW

Weight of empty hanger T0= 1.0 Kg Brake drum net wt. T = (T0+T1-T2)kg

Turbine output O = 3.14xDxNxT/(102x60) kW

Efficiency= Output/Inputxl00%

Tabular column

Sl.No Inlet.

Press.

P

Kg/sq.

cm

Outlet

Vac.

V

mm

of

Hg

Total

Head

H

m of

water

Venturimeter Press.

Gauge

readings

Flow

rate

Q

cu.m/

sec

Speed

N

rpm

Wt.on

Hanger

T1 Kg

Spring

balance

T2 Kg

Net

Wt

T

Kg

Output

O

kW

Input

I

kW

Efficiency

%

P1

Kg/sq.

cm

P2

Kg/sq.

cm

dH

m

of

water






4. PERFOMANCE TEST ON CENTRIFUGAL PUMP

Aim:

To conduct a test on a single stage centrifugal pump at various speeds to obtain the pump characteristics.

Description:

Centrifugal Pump consists of an impeller rotating inside a casing. The impeller has a number of curved

vanes. Due to the centrifugal force developed by the rotation of the impeller, water entering at the center

flows outwards to the periphery. Here it is collected in a gradually increasing passage in the casing known as

a volute chamber This chamber converts a part of the velocity head (kinetic energy) of the water into

pressure head (potential energy). For higher heads, multistage centrifugal pumps having two or more

impellers In series will have to be used.

The test pump is a single stage centrifugal pump of size 2"x1.5" (50mmx40mm.) It is coupled to a 2 HP

capacity three phase AC motor by means of Li cone pulley belt drive system.

An energy meter and a stop watch are provided to measure the input to the motor and a collecting tank to

measure the actual discharge. A pressure gauge and a vacuum gauge are fitted in the delivery and suction

pipe lines to measure the pressure.

NOTE: Since the centrifugal pump is not self priming, the pump must be filled with water (priming) before

starting. For this reason, water should not be allowed to drain and a foot valve is provided,


1. Loosen the V-belt by rotating the hand wheel of the motor bed and position the V-belt in the required

groove of the pulley.

2. Prime the pump with water if required

3. Close the gate valve completely

4. Start the motor and adjust the gate valve to required pressure



5. Note the following readings (a) The Pressure gauge reading P kg/sq, cm

b) The vacuum gauge reading V mm of Hg

c) Time for 10 revolutions of energy meter disc -Tsecs

d) Time for 10 cm rise in the collecting tank - t secs

e) Elevation difference between the pressure and vacuum

gauge -X m of water (55 cm in this case)

Take 3 or 4 sets of readings by varying the head from a maximum at shut off to a minimum

where gate valve is fully open.

Calculation:

1. Discharge:

Time for 10 cm rise = t secs

Area of tank = 0.8x0.8 sq. m

Pump discharge Q = (0.64 x 0. 1)/t cu.m /sec

2. Head:

Total Head H = 10 (P + V/760) + X m of water (55 cm in this case)

3. Output of the pump:

Pump output = (9.81 QH) KW

= (1000 Q H /75) HP

4. Input of the Motor:

Energy meter constant N = 200 revs/kW hr

Time for 10 revolution = T secs.

Input to motor = (3600x 10)/(200xT) kW

Efficiency of motor = 80% (assumed)

Belt transmission efficiency = 90% (assumed)



Pump input = (3600x 10)/(200xT) x 0.9x 0. 8 kW

= 129.6/T kW

5. Efficiency:

Pump Efficiency = Pump output/Pump input


Collecting tank area = 0.8x0.8 sq.m

Energy meter constant = 200 rev/KW Hr

Discharge Q = A r/t = 0.64x0.1/t cu,m/sec

Total Head H = (P+V/760)10+X m of water

Pump output =1000 QH/75 HP =9.81 QH kW

Input = (3600x 10x0.8x0. 9)/ (200xT) kW = 129.6/T kW

Efficiency = Output/Input

Tabular column

Where P is Input power, η is Efficiency, Q is discharge& N is speeding rpm

Where P is Input power, η is Efficiency, Q is discharge& N is speeding rpm

Sl.No

Pump

Speed N

rpm

Pressure

gauge P

Kg/sq cm

Vacuum

Gauge V

mm of Hg

Total

Head H

m of

water

Time

for10cm

rise in

Coll. Tank

-t seconds

Discharge ×

10-3

Q cu. m/see

Time for

10

revol.of

energy

meter disc

-T

seconds

Input

kW

Output

kW

Efficienc

y%





5. PERFOMANCE TEST ON RECIPROCATING PUMP TEST Aim:

To study the characteristics of a reciprocating pump

Description:

The Reciprocating pump is a positive displacement type pump and consists of a piston or a plunger working

inside a cylinder. The cylinder has two valves, one allowing water into the cylinder from the suction pipe

and the other discharging water from the cylinder into the delivery pipe.

Specification of the pump:

Type: Double acting single cylinder

(a) Piston Stroke, L=1 3\4 “(44.5 mm)

(b) Piston Diameter=1 1/2" (38mm)

(c) Suction pipe=1 " (25mm)

(d) Delivery pipe=3\4" (18mrn)

An energy meter is provided to determine input power to the motor. The pump, is belt driven by the

Motor. The pump can be run at four different speeds by the use of V-belt and the differential pulley system,

Special arrangement is provided for quick alteration of speed. The belt can be put in different grooves of the

pulleys for different speeds quickly by loosening the belt. A set of pressure gauge and vacuum gauges are

provided along with the required pipe lines


(1) Start. the motor.

(2) Note the following readings -

(a) The pressure gauge reading P kg/sq-cm

(b) The distance between the water level and the pressure gauge – X m.(7cm in this case)

(c) Tin-& for 10 revolution energy meter disc - T -secs

(d) Time for 10 cm rise in collecting tank - t secs

Take 5- 6 sets of readings by varying the head from maximum at shut off to minimum where gate

valve is fully open. This is done by throttling the delivery valve.

Calculations:

1. Pump output

Time for 10cm.rise. = t secs.

Area of the tank. A = 0.5×0.5 sq.m

Pump discharge Q = (0.25×0.1)/t m3/s.

Delivery pressure = P kg/sq.cm

Suction pressure = V mm of Hg

Pump delivery head H = (P+V/760) × 10 m of water

Output of the pump = 9.81×H×Q kW



2. Pump Input:

Energy meter constant N = 1200 Revs/kWhr.

Time for 10 Revolutions = T secs.

Input to the motor = 3600x0.8x10/NTkW

Where, 0.8 is the Motor efficiency

Input to the Pump = motor input×0.9

= 3600×10×0.8×0.9/ (l200× T)

= 21.6/T kW

Where, 0.9 is the belt transmission efficiency

Overall efficiency = (output/input) × I00 %

Theoretical Discharge Qth = 2 LAN / 60 (double acting pump)

L, Piston Stroke =1 3\4 " (44.5 mm)

A, Cylinder area = 3.14×d2/4

d, Piston Diameter =1 1/2" (38mm)

% Slip =(Qth –Qact)/Qth


Collecting tank area =0.5xO.5sq.m

Energy/meter constant = 1200 rev/KW Hr

Discharge Q= Ar/t = (0.25x0.1)/ t cu.m /sec

Total Head H= (P+ V/7 60)10+X m of water

Pump output=9.81QH KW

Input= (3600x 10x0.8x0.9)/ (1200T) kW

Efficiency= Output/Input

Tabular column

Sl.

No

Pump

speed

N

rpm

Pressure

gauge P

kg/sq

cm

Vacuum

Gauge

Head v

mm of

Hg

Total

Head

H m

of

water

Time

for

10cm

rise in

Coll.

tank ,t

seconds

Discharge

Q Cu.m

/sec

Time

for 10

revol.

of

energy

meter

disc- T

seconds

Input

KW

Output

KW

Efficiency

%

%

slip





7. SUMBERSIBLE PUMP TEST RIG

Aim:

To conduct a test on a submersible pump to obtain the pump characteristics.

Description:

The vertical Submersible pump is a multistage pump set with each set made of a mixed flow impeller with

axial diffuser assembly. The shaft of pump is connected to a motor which is housed on the bottom of he set

The Pump and motor assembly is fully submerged in water. An integral foot valve is at the bottom set of the

pump assembly the submersible pump is used to lift water from bore wells.

The test rig consists of a 3-stage submersible pump driven by a 3 HP motor (440Volts. 3-phase) and suitable

50 mm (2.") Pipelines. A pressure gauge is fitted in the delivery pipe line to measure the delivery head An

energy meter and stopwatch are provided to measure the input to the motor and a collecting tank to measure

the actual discharge,

NOTE.- AS the motor driving the submersible pump is also submerged, it is cooled by water unlike other

motor pump sets which are air cooled. Hence, prior to operating the pump set the motor should be filled with

water as instructed in the pump user manual. The operator is also expected to be read the user manual and be

completely thorough with the operation of submersible pump.

Calculation:

I. Discharge:

Area of the tank A= 0.8 x O.8 Sq. m

Rise of level h= 0.1m

Volume collected Ax h= 0.064 cu.m

Time taken= t secs.

Discharge Q = Volume/time = (0.064)/t cu.m/s

II. Head:

Total delivery head H= (10 P + Hs) m of water

III Output of the pump:

Out output=9.81xQxH kW =1000 xQxH/75 HP

IV. Input to the motor:

Energy meter constant N=200 revolution per kWh

Time for 10 revolutions= T secs

Input to motor= (3600/200) x (10/T) kW = 180/T kW

Assuming 0.8 is the motor efficiency.

Input to the pump= 0.8x Input to motor =144/T KW

V. Efficiency

Pump efficiency = Output /Input 100%




Collecting tank area =0.8 x0.8 8 sq.m

Energy meter constant=200 rev/kW Hr

Discharge Q= Ar/t = (0.64x0.1)/t cu.m/sec

Total Head H= Px10 =X m of water =9.91QH kW

Pump output = (3600x10x0.8)/ (200xT) kW

Input=144.0/T kW

Efficiency= Output/Input

Tabular column

Sl.No Pressure

gauge P,

.Kg./sq

m

Total

Head,H

m in of

water

Time for

10cm

rise in

Coll.

Tank – t

seconds

Discharge

Q

cu.m/sec

Time for

10 revol.

of

energy

meter

disc -T

seconds

Input -

kW

Output-

kW

Efficiency

%

-

HM Laboratory Manual 2012

Documents

avoid excessive

saint gits

throat dia

add additional

eulers head

cast iron

brake drum

double acting