FLUID MECHANICS AND HYDRAULIC MACHINERY JNTU previous years question papers

FLUID MECHANICS AND HYDRAULIC MACHINERY JNTU previous years question papers



Time: 3 hours Max Marks: 80

Answer any FIVE Questions

All Questions carry equal marks

1. (a) Differentiate between simple manometers and differential manometers. Draw neat sketches of the manometers and explain.
(b) In a pitot static tube the stagnation pressure is 3.0kpa and the static pressure is 3.0kpa(guage). The fluid is air (?=1.20kg/m3). Calculate the velocity of flow by taking the instrument coefficient as 0.98. [10+6]

2. (a) Draw the datum line, hydraulic gradient line and total energy line for a fluid flow in a diverging pipe line and discuss.
(b) Petrol of specific gravity 0.68 is flowing through a pipe of diameters 600 mm and 400mm at the bottom and upper ends respectively. The pressure at the bottom end is 280 Kpa and at the upper end it is 100 Kpa. The flow of petrol in the pipe is at the rate of 75lit/sec. Find the difference in elevations of the two ends. [8+8]

3. (a) Draw a neat sketch of a flow nozzle and explain its working. Discuss on which principle it works.
(b) A pitot tube was used to measure the quantity of water flowing in a pipe of 0.30m diameter. The water was raised to a height of 0.25m above the centre line of pipe in the vertical limb of the tube. If the mean velocity is 0.78 times the velocity at the center and coefficient of pitot tube is 0.98, find the discharge in the pipe line. The static pressure head at the center of the pipe is 0.2m. [8+8]

4. (a) A jet of water strikes with a velocity of 50 m/sec a flat fixed plate inclined at 30 degrees with the axis of the jet. The cross sectional area of the plate is 100 cm2. Find the force exerted by the jet on the plate and the ratio in which the jet gets divided after striking.
(b) Derive the equation for the impact of jet striking a curved plate at the centre when the plate is stationary. [8+8]

5. (a) Describe the status of hydroelectric power in India.
(b) Explain how the load factor, capacity factor and utilization factor interrelated. Also explain the significance of diversity factor. [8+8]

6. (a) Draw a schematic diagram of a Francis turbine and explain briefly its construction and working.(b) A Pelton wheel having a mean bucket diameter of 1.0 m is running at 1000 r.p.m. the side clearance angle is 150 and discharge through the nozzle is 0.1 m3/s, determine power available at the nozzle and hydraulic efficiency of the turbine. [16]

7. (a) Obtain an expression for unit speed, unit discharge and unit power for a turbine.
(b) A Pelton wheel is revolving at a speed of 200 r.p.m. and develops 5886 kW S.P when working under a head of 200 m with an overall efficiency of 80%. Determine unit speed, unit discharge and unit power. The speed ratio for the turbine is given as 0.48. Find the speed, discharge and power when this turbine is working under a head of 150 m. [8+8]

8. (a) Show from first principle that the work saved, against friction in the delivery pipe of a single-acting reciprocating pump, by fitting an air vessel is 84.8% while for a double-acting reciprocating pump the work saved is only 39.20%.
(b) What is negative slip in a reciprocating pump? Explain with neat sketches the function of air vessels in a reciprocating pump.

FEEL USEFUL PLEASE GIVE +1