D $2009 Pages: 2

Reg. No. Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
FOURTH SEMESTER B.TECH DEGREE EXAMINATION, DECEMBER 2018
Course Code: CE206
Course Name: FLUID MECHANICS -II.
Max. Marks: 100 Duration: 3 Hours

Answer any two Questions from each part.
PARTA

1. a) Derive an expression for maximum hydraulic efficiency of a Pelton wheel. (5)
b) A jet of water having a velocity of 45m/s impinges without shock a series of vanes
moving at 15m/s, the direction of motion of the vanes being inclined at 20° to that of
the jet. The relative velocity at outlet is 0.9 of that at inlet, and the absolute velocity of
the water at exit is to be normal to the motion of the vanes. Find: (a) vane angles at
entrance and exit (b) work done on vanes per unit weight of water supplied by the jet;
and (c) the hydraulic efficiency. (10)

2. a)Explain with figure the function of a surge tank in a hydroelectric plant. (5)
b)Determine the overall efficiency of a Kaplan turbine developing 3000kW under a net
head of 5m.It is provided with a draft tube with its inlet diameter 3m set 1.6m above the
tail race level. A vacuum gauge connected to the draft tube indicates a reading of Sm of
water. Assume draft tube efficiency as 78%.Neglect losses in the

draft tube. (10)
3. a) Define the terms (i) Specific speed of a centrifugal pump and (ii) Net Positive
Suction Head. (5)

b)The diameter of an impeller of a centrifugal pump at the inlet and outlet are 36cm and
72cm respectively. The velocity of flow at outlet is 2.4m/s and the vanes are set back at
angle of 45° at outlet. Determine the minimum starting speed if the

manometric efficiency is 70%. (10)
PART B

4. a) Differentiate between (i) Gradually varied flow and rapidly varied flow,
(ii)subcritical and supercritical flow. (6)
b) A trapezoidal channel with side slopes of 2 horizontal : 1 vertical has to be designed
to carry 15 m*/s at ೩ slope of 1/5000. Determine the dimensions of the
efficient section.Manning’s coefficient is 0.014. (9)

5. a) A rectangular channel 3.5m wide is laid on a slope of 0.0005. Calculate the normal
depth of flow for a discharge of 5m*/s in this channel. The Manning’s coefficient can
be taken as 0.02. (7)

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