VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur – 603 203 DEPARTMENT OF MECHANICAL ENGINEERING QUESTION BANK III SEMESTER - CE6451 - FLUID MECHANICS AND MACHINERY Regulation – 2013 Academic Year 2017 – 18 Prepared by Mr. K.VELAVAN, Assistant Professor Mr. T.MUTHU KRISHNAN, Assistant Professor Mr. P.VIJAYAN, Assistant Professor
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VALLIAMMAI ENGINEERING COLLEGE
SRM Nagar, Kattankulathur – 603 203
DEPARTMENT OF MECHANICAL ENGINEERING
QUESTION BANK
III SEMESTER - CE6451 - FLUID MECHANICS AND MACHINERY
Regulation – 2013
Academic Year 2017 – 18
Prepared by
Mr. K.VELAVAN, Assistant Professor
Mr. T.MUTHU KRISHNAN, Assistant Professor
Mr. P.VIJAYAN, Assistant Professor
VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur – 603 203.
DEPARTMENT OF MECHANICAL ENGINEERING
QUESTION BANK
SUBJECT : CE6451 - FLUID MECHANICS AND MACHINERY
SEM / YEAR : III / II
UNIT I - FLUID PROPERTIES AND FLOW CHARACTERISTICS
UNIT-I SYLLABUS
Units and dimensions- Properties of fluids- mass density, specific weight, specific volume, specific gravity,
viscosity, compressibility, vapor pressure, surface tension and capillarity. Flow characteristics– concept of control
volume - application of continuity equation, energy equation and momentum equation.
PART - A ( 2 MARKS )
S.No QUESTIONS LEVEL COMPETENCE
1. Define density and weight density. BTL1 Remember
2. Define Newton law of Viscosity. BTL1 Remember
3. What are the properties of ideal fluid? BTL2 Understand
4. Define Specific Volume and Specific Weight. BTL1 Remember
5. Define compressibility. BTL1 Remember
6. What is meant by vapor pressure of a fluid? BTL2 Understand
7. Analyze Non-Newtonian fluids? Give examples. BTL4 Analyze
8. What do you mean by absolute pressure and gauge pressure? BTL2 Understand
9. Define the term Kinematic Viscosity and give its dimensions. BTL1 Remember
10. What is specific gravity? How is it related to density? BTL3 Apply
11. Define surface tension and capillarity? BTL1 Remember
12. Analyze the effect of temperature on viscosity of liquids and gases BTL4 Analyze
13. Calculate the mass density and sp. volume of 1 litre of a liquid which weighs 7N
BTL6 Create
14. Differentiate kinematic viscosity with dynamic viscosity. BTL2 Understand
15. What is meant cavitations? BTL1 Remember
16. What are the assumptions of the Bernoulli‟s equations? BTL4 Analyze
17. What is the use of control volume? BTL2 Understand
18. State assumption made in deriving continuity equations. BTL4 Analyze
19. Define - Incompressible fluid? BTL1 Remember
20. State the equation of continuity to three dimensional in compressible flow.
BTL1 Remember
PART - B ( 13 MARKS )
S.No QUESTIONS LEVEL COMPETENCE
1 The space between two square flat parallel plates is filled with oil. Each
side of the plate is 60 cm. The thickness of the oil film is 12.5 mm. The
upper plate, which moves at 2.5 m/s requires a force of 98.1 N to maintain
the speed. Determine the dynamic viscosity of the oil and the kinematic
viscosity of the oil in stokes if the specific gravity of the oil is 0.95
BTL4
Analyze
2 (i) If 5 m
3 of a certain oil weighs 40 kN, Evaluate the Specific Weight,
Mass Density and Specific Gravity of this Oil. (6)
BTL5
BTL5
Evaluate
Evaluate (ii) At a certain point in castor oil the shear stress is 0.216 N/m
2 and the
velocity gradient 0.216s-1
. If the mass density of castor oil is 959.42
kg/m3, Evaluate kinematic viscosity. (7)
3 (i). A plate 0.05 mm distant from a fixed plate, moving at 1.2 m/s
requires a force of 2.2 N/m2 to maintain its speed. Find the dynamic
viscosity of fluid between the plates. (5)
BTL4
Analyze
(ii). Calculate the capillary rise in a glass tube of 4 mm diameter, when
immersed in (a) water and (b) mercury. The temperature of the liquid is
20oC and the values of the surface tension of water and mercury at 20
oC
in contact with air are 0.073575 N/m respectively. The angle of contact
for water is zero that for mercury 1.30o. Take density of water at 20
oC as
equal to 998 kg/m3. (8)
BTL4
Analyze
4
A pipe (1) 450 mm in diameter branches in to two pipes (2 and 3) of
diameters 300 mm and 200 mm respectively. If the average velocity in
450 mm diameter pipe is 3m/s. Find, (i). Discharge through 450 mm
diameter pipe;(ii)Velocity in 200 mm diameter pipe if the average
velocity in 300 mm pipe is 2.5 m/s
BTL4
Analyze
5
A 30 cm x 15 cm venturimeter is provided in a vertical pipe line
carrying oil of specific gravity 0.9, the flow being upwards. The
difference in elevation of the throat section and entrance section of the
venturimeter is 30 cm. The differential U tube mercury manometer
shows a gauge deflection of 25 cm. Calculate: (a) the discharge of oil.
(b) The pressure difference between the entrance section and the throat
section. Take Cd=0.98 and specific gravity of mercury as 13.6
BTL4
Analyze
6
A vertical venturimeter 40 cm x 20 cm is provided in a vertical pipe to
measure a flow of oil of relative density 0.8. The difference in
elevations of the throat section and the entrance sections in 1 m, the
direction of flow of oil being vertically upwards. The oil-mercury
differential gauge shows deflection of mercury equal to 40 cm.
Determine the quantity of oil flowing the pipe. Neglect losses.
BTL4
Analyze
7
A horizontal venturimeter with inlet and throat diameter 300 mm and
100 mm respectively is used to measure the flow of water. The pressure
intensity at inlet is 130 kN/m2 while the vacuum pressure head at throat
is 350 mm of mercury. Assuming that 3% head lost between the inlet
and throat. Find the value of coefficient of discharge for the
venturimeter and also determine the rate of flow.
BTL4
Analyze
8
A 45o reducing bend is connected in a pipe line, the diameters at the
inlet and outlet of the bend being 600 mm and 300 mm respectively.
Find the force exerted by water on the bend if the intensity of pressure at
inlet to bend is 8.829 N/cm2 and rate of flow of water is 600 liters/s.
BTL4
Analyze
9
A 300 mm diameter pipe carries water under a head of 20 m with a
velocity of 3.5 m/s. If the axis of the pipe turns through 45o, find the
magnitude and direction of the resultant force at the bend.
BTL4
Analyze
10 Derive Bernoulli equation from Euler‟s equation of motion and Derive
continuity equation
BTL6
Create
11
A drainage pipe is tapered in a section running with full of water. The
pipe diameter of the inlet and exit are 1000 mm and 500 mm
respectively. The water surface is 2m above the centre of the inlet and
exit is 3m above the free surface of the water. The pressure at the exit
is250 mm of Hg vacuum. The friction loss between the inlet and exit of
the pipe is1/10 of the velocity head at the exit. Determine the discharge
through the pipe.
BTL4
Analyze
12
i) Water is flowing through a pipe of diameter 30 cm and 20 cm at the
section 1 and 2 respectively. The rate of flow through pipe is 35 lps. The
section 1 is 8 m above datum and section 2 is 6 m above datum. If the
pressure at section 1 is 44.5 N/cm2. Find the intensity of pressure at
section 2. (7)
BTL4
Analyze
ii) Calculate the dynamic viscosity of oil which is used for lubrication
between a square plate of size 0.8m x 0.8m and an inclined plane with
angle of inclination 30o. The weight of the square plate is 330 N and it
slide down the inclined plane with a uniform velocity of 0.3 m/s. The
thickness of the oil film is 1.5 mm. (6)
BTL4
Analyze
13
i) Water flows at the rate of 200 litres per second upwards through a
tapered vertical pipe. The diameter at the bottom is 240 mm and at the
top 200 mm and the length is 5 m. The pressure at the bottom is 8 bar,
and the pressure at the topside is 7.3 bar. Determine the head loss
through the pipe. Express it as a function of exit velocity head. (7)
BTL4
Analyze
ii) Determine the viscous drag torque and power absorbed on one
surface of a collar bearing of 0.2 m ID and 0.3 m OD with an oil film
thickness of 1 mm and a viscosity of 30 centipoises if it rotates at 500
rpm (6)
BTL4
Analyze
14
A pipe 200 m long slopes down at 1 in 100 and tapers from 600 mm
diameter at the higher end to 300 mm diameter at the lower end, and
carries 100 litres/ sec of oil having specific gravity 0.8. If the pressure
gauge at the higher end reads 60 KN/m2, determine the velocities at the
two ends and also the pressure at the lower end. Neglect all losses.
BTL4
Analyze
PART - C
S.No QUESTIONS LEVEL COMPETENCE
1
Water flows through a pipe AB 1.2 m diameter at 3 m/s and then passes
through a pipe BC 1.5 m diameter. At C, the pipe branches. Branch CD
is 0.8 m in diameter and carries one third of the flow in AB. The flow
velocity in branch CE is 2.5 m/s. Find the volume rate of flow in AB,
the velocity in BC, the velocity in CD and the diameter of CE.
BTL 5
Evaluate
2
Find the discharge of water flowing through a pipe 30 cm diameter
placed in an inclined position where a venturimeter is inserted, having a
throat diameter of 15 cm. The difference of pressure between the main
and throat is measured by a liquid of specific gravity 0.6 in an inverted
U tube which gives a reading of 30 cm. The loss of head between the
main and throat is 0.2 times the kinetic head of the pipe.
BTL 5
Evaluate
3 A liquid has a specific gravity of 0.72. Find its density, specific weight
and its weight per litre of the liquid. If the above liquid is used as the
lubrication between the shaft and the sleeve of length 100 mm.
Determine the power lost in the bearing, where the diameter of the shaft
is 0.5 m and the thickness of the liquid film between the shaft and the
sleeve is 1 mm. Take the viscosity of fluid as 0.5 N-s/m2 and the speed
of the shaft rotates at 200 rpm.
BTL4
Analyze
4
i) Calculate the specific weight, density and specific gravity of one litre of a liquid which weighs 7 N. (5)
BTL 3 Apply
ii) An oil of specific gravity 0.8 is flowing through a venturimeter having inlet diameter 20 cm and throat diameter 10 cm. The oil-mercury differential manometer shows a reading of 25 cm. Calculate the discharge of oil through the horizontal venturimeter. Take Cd = 0.98 (8)
BTL 3 Apply
UNIT II: FLOW THROUGH CIRCULAR CONDUITS
UNIT-II SYLLABUS
Hydraulic and energy gradient - Laminar flow through circular conduits and circular annuli-Boundary layer