Jawaharlal Nehru Technological University Kakinada 2008 B.Tech Electrical and Electronics Engineering FLUID MECHANICS AND HYDRAULIC MACHINERY - Question Paper

The inlet angle of the vane is zero and the outlet angle is 30 degrees. compute
the resulting force on the vane when it is moving with a velocity of 12m/sec
in the direction of the jet.
(b) State the formula used to ?nd out the impact of jet on vanes. Derive the
formula for resulting thrust when a jet strikes a stationary inclined ?at plate.
[8+8]
5. (a) What is a run o? river plant. elaborate the di?erent parts and arrangements
of such plants? Draw a neat sketch and discuss
(b) What is meant by ?ow duration curve and power duration curve. How do you
di?erentiate these 2 curves? Also discuss power duration curve in detail.
[8+8]
6. (a) Di?erentiate between:
i. The impulse and reaction turbines,
ii. Radial and axial ?ow turbines,
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iii. Inward and outward radial ?ow turbine, and
iv. Kaplan and propeller turbines.
(b) A Pelton wheel is having a mean bucket diameter of 0.8 m and is running at
1000 r.p.m. The net head on the Pelton wheel is 400 m. If the side clearance
angle is 150
and discharge through nozzle is 150 litres/s, ?nd:
i. Power available at the nozzle, and
ii. Hydraulic e?ciency of the turbine. [16]
7. (a) By means of a neat sketch discuss the governing mechanism of Francis Turbine.
(b) A Hydraulic turbine is to develop 845.6 kW when running at 100 r.p.m. under
a head of 10 m. Work out the maximum ?ow rate and speci?c speed for the
turbine if the overall e?ciency at the best operating point is 92 percent. In
order to predict its performance, a 1:10 scale model is tested under a head of
6 m. What would be the speed, power output and water consumption of the
model if it runs under the conditions similar to the prototype? [8+8]
8. (a) What is the e?ect of acceleration in suction and delivery pipes on indicator
diagram? Does the area of the indicator diagram change as compared to the
area of ideal indicator diagram?
(b) A centrifugal pump impeller whose external diameter and width at the outlet
are 0.8 m and 0.1 m respectively is running at 550 r.p.m. The angle of impeller
vanes at outlet is 40. The pump delivers 0.98 m3
of water per 2nd under an
e?ective head of 35 m. If the pump is driven by a 500 kW motor, determine:
i. The manometric e?ciency
ii. The overall e?ciency, and
iii. The mechanical e?ciency. presume water enters the vanes radially at inlet.
[8+8]
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2 of 2Code No: 07A3EC02 Set No. 4
II B.Tech I Semester Regular Examinations, November 2008
FLUID MECHANICS AND HYDRAULIC MACHINERY
( Common to Electrical & Electronic Engineering and Production
Engineering)
Time: three hours Max Marks: 80
ans any 5 ques.
All ques. carry equal marks
? ? ? ? ?
1. (a) De?ne dynamic viscosity and kinematic viscosity. elaborate their units? Ex-
plain the signi?cance of viscosity on ?uid motion.
(b) obtain the pressure in N/m2
represented by a column of
i. 10cm of water
ii. five cm of oil of relative density 0.75
iii. 2cm of mercury. [8+8]
2. (a) Derive the formula of continuity in di?erential form.
(b) Determine whether the subsequent velocity components satisfy the continuity
equation:
i. u = 2x2
+ zy, v = -2xy + 3y3
+ 3zy, w = -3/2 z2
- 2xy - 6yz
ii. u = -cx/y, v = c log xy. [6+10]
3. (a) discuss how do you measure the velocity of ?owing water in a stream using
pitot tube.
(b) An oil of relative density 0.90 ?ows through a vertical pipe of diameter 20cm.
The ?ow is measured by a 20cm × 10cm venturimeter. The throat is 30cm
above the inlet part. A di?erential U tube manometer containing mercury
is connected to the throat and the inlet. If coe?cient of discharge is 0.99 what
is the manometer studying for a ?ow of 50lit/sec. [6+10]
4. (a) A 15 cm diameter jet of water with a velocity of 20 m/sec strikes a plate
normally. If the plate is moving with a velocity of 8m/sec in the direction of
the jet, compute the work done per 2nd on the plate and the e?ciency of
the energy transfer.
(b) Prove that the force exerted by a jet of water on a ?xed hemispherical curved
vane when the jet strikes at the centre is F = ?av2
where
? = Mass density of water
a = Area of cross part of the jet
v = Velocity of the jet. [8+8]
5. (a) elaborate valves used in a penstock. discuss with neat sketches, different kinds
of valves with their suitability under different conditions.
(b) What is intake structures. discuss di?erent kinds with the help of neat
sketches.
[8+8]
1 of 2Code No: 07A3EC02 Set No. 4
6. (a) How will you classify the turbines? discuss
(b) A Pelton wheel is to be designed for the subsequent speci?cations. Power
=735.75 kW S.P. Head = 200 m, Speed = 800 r.p.m., ?0 = 0.86 and jet
diameter is not to exceed one-tenth of the wheel diameter. Determine :
i. Wheel diameter,
ii. The number of jets required, and
iii. Diameter of the jet. Take Cv = 0.98 and speed ratio = 0.45. [16]
7. (a) What is cavitation? How can it be avoided in reaction turbine?
(b) What is governing and how it is accomplished for di?erent kinds of water
turbines?
[8+8]
8. (a) Draw an indicator diagram, considering the e?ect of acceleration and friction
in suction and delivery pipes. obtain an expression for the work done per second
in case of single-acting reciprocating pump.
(b) A single-acting reciprocating pump having a bore of 150 mm and a stroke of
300 mm is raising water to height of 20 m above the sump level. The pump
has an true discharge of 0.0052 m3
/s. The e?ciency of the pump is 70%. If
the speed of pump is 60 r.p.m. Determine:
i. Theoretical discharge
ii. Theoretical power
iii. true power, and
iv. Percentage slip. [8+8]
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Earning:   Approval pending.