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

(b) 2 reservoirs are connected by a pipeline consisting of 2 pipes in series,
one of 15 cm diameter and 6m long and a different of 22.5 cm diameter and 15m
long. If the di?erence in water levels of the reservoirs is 6m, compute the
discharge by considering all the losses. presume f = 0.02 for both the pipes.
[8+8]
4. (a) A jet of water of 86 mm diameter strikes a curved vane at the centre with a
velocity of 30 m/sec. The curved vane is moving with a velocity of 8m/sec in
the direction of the jet. obtain the force exerted on the plate in the direction of
the jet, power and e?ciency of the jet. presume that the plate is smooth.
(b) Explain, how you ?nd the impact of jet striking an unsymmetrical ?xed curved
plate at 1 of the tips. [8+8]
5. (a) define the status of hydroelectric power in India.
(b) discuss how the load factor, capacity factor and utilization factor interrelated.
Also discuss the signi?cance of diversity factor. [8+8]
6. (a) In a Pelton wheel the buckets de?ect the jet through 1700
and the relative
velocity is decreased by 12% due to bucket friction. For a speed ratio of 0.47,
1 of 2Code No: 07A3EC02 Set No. 2
compute from ?rst principles the hydraulic e?ciency of the wheel. The bucket
circle diameter of the wheel is 0.9 m and there is 1 jet for which Cv = 0.98.
The true e?ciency of the wheel is 0.9 times its theoretical e?ciency. The
wheel develops 1700 kW under a head of 550 m. Calculate:
i. The speed of wheel in r.p.m and
ii. The diameter of the nozzle.
(b) A Francis turbine has to be designed to develop 367.5 kW under a head of H
= 70 m while running at N = 750 r.p.m. Ratio of width of runner to diameter
of runner, n = 0.1, inner diameter is half the outer diameter. Flow ratio =
0.15, hydraulic e?ciency = 95%, mechanical e?ciency = 84%. 4 percent
of the circumferential area of runner to be occupied by the thickness of vanes,
velocity of ?ow is constant and the discharge is radial at exit. Calculate:
i. The diameter of the wheel,
ii. The volume of water supplied, and
iii. The guide vane angle at inlet and runner vane angles at inlet and exit.
[16]
7. (a) De?ne the terms ‘unit power’, ‘unit speed’ and ‘unit discharge’ with reference
to a hydraulic turbine. Also derive expressions for these terms.

Earning:   Approval pending.