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6. a)A circular tank of diameter 3 m contains water up to a height of 4 m. The tank is
provided with an orifice of diameter 0.4 m at the bottom. Find the time taken by water,
(i) to fall from 4 m to 2 m and (ii) for completely emptying the tank. Take Ca =
0.6. (10)
b) Define energy correction factor and momentum correction factor.

PART ^
Answer any two Questions

7. a) Derive the Hagen —Poiseulle equation for laminar flow in circular pipes. (10)
b) A piping system consists of three pipes arranged in series; the lengths of the pipes
are 1200 m, 750 m and 600 m and diameters 750 mm, 600 mm and 450 mm
respectively. (i) Transform the system to an equivalent 450 mm diameter pipe, and (ii)
Determine an equivalent diameter for the pipe, 2550 m long. (10)

8. a) The velocity distribution in the boundary layer is given by
w/U = 2(y/8) -(y/8) 2.8 being boundary layer thickness. Find (i) the displacement

thickness, (ii) the momentum thickness and (iii) the energy thickness. (10)

b) What are the major and minor losses in a pipeline? (5)

c) Define momentum thickness and energy thickness. (5)
9. a) What 15 the difference between friction drag and pressure drag? (5)

b) Calculate the friction drag on a plate 0.15 m wide and 0.45 m long placed
longitudinally in a stream of oil flowing with a free stream velocity of 6 m/s. Also
find the thickness of the boundary layer and shear stress at the trailing edge. Specific

gravity of oil is 0.925 and its kinematic viscosity is 0.9 x 105/6. (10)
௦) Define Hydraulic Grade Line and Total Energy Line. (5)

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