Applied Hydraulics - 1 - Dec 2015
Civil Engineering (Semester 5)
TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.
Solve any Four:
1 (a) Define Moment of Momentum Equation.(5 marks)
1 (b) Explain the term Similitude.(5 marks)
1 (c) Explain Jet Propulsion of Ships.(5 marks)
1 (d) Write a short note on specific speed of turbine.(5 marks)
1 (e) What is Cavitation in Pump.(5 marks)
1 (f) Write a short notes on Hydraulic Accumulator.(5 marks)
2 (a) The diameter of a pipe bend is 0.3m at inlet and 0.15m at outlet and the flow is turned through 120° in a vertical plane. The axis at inlet is horizontal and centre of the outlet section is 1.5m below the centre of inlet section. The total volume of fluid contained in the bend is 0.085 m3. Neglecting friction, calculate the magnitude and direction of the force exerted on the bend by the water flowing through it at 225 1/s when the inlet pressure is 137.34 kN/m2.(10 marks)
2 (b) A twin jet unequal lawn sprinkler delivers a total discharge of 1.5 lps. Taking jet diameter as 0.9 cm, inclination of jet with the axis of pipe 45° in opposite directions and distance from the axis of rotation to jet 15 cm and 30 cm. Neglecting friction, find speed of sprinkler and torque required to keep the sprinkler stationary.(10 marks)
3 (a) A ship 300m long moves in sea water, whose density is 1030 kg/m3. A 1:100 model of this ship is to be tested in a wind tunnel. The velocity of air in the wind tunnel around the model is 30 m/s and the resistance of the model is 60 N. Determine the velocity of ship in sea-water and also the resistance of the ship in sea water. The density of air is given as 1.24 kg/m3. Take the kinematic viscosity of sea water and air as 0.012 strokes and 0.018 strokes respectively.(10 marks)
3 (b) A jet propelled boat, moving with a velocity of 5.5 m/s, draws water amid-ship. The water is discharged through two jets provided at the back of the ship. The diameter of each jet is 155 mm. The total resistance offered to the motion of the boat is 4905 N. Determine:
(a) Volume of water drwan by the pump per sound, and
(b) Efficiency of the jet propulsion.(10 marks) 4 (a) Penstock Supplies water from a reservoir to the Pelton wheel with a gross head of 500m. One third of the gross head is lost in friction in the penstock. The rate of flow of water through the nozzle fitted at the end of the penstock is 2.0 m3/s. The angle of deflection of jet is 165°. Determine the power given by the water to the runner and also hydraulic efficiency of the pelton wheel. Take speed ratio=0.45 and Cv=1.0.(10 marks) 4 (b) An outward flow reaction turbine has internal and external diameters of the runner as 0.5m and 1.0m respectively. The guide blade angle is 15° and velocity of flow is 4.0 m/s and is constant. If its speed 200 rpm, head 10 m and discharged at outlet is radial, find
(a) runner vane angles at intel and outlet.
(b) Work done/sec./kg of water.
(c) Hydraulic efficiency.(10 marks) 5 (a) A hub diameter of Kaplan turbine working under head of 14 m is 0.35 times the diameter of the runner. The turbine is running at 100 rpm. If vane angle of the extreme edge of runner at outlet is 20° and flow ratio 0.6. Find:
(a) Diameter of runner
(b) Diameter of Boss
(c) Discharged through runner.(10 marks) 5 (b) A conical draft tube having inlet and outlet diameters 1m and 1.5 m discharges water at outlet with a velocity of 2.5 m/s. The total length of the draft tube is 6m and 1.3m of the length of draft tube is immersed in water. If the atmosperic pressure head is 10.3 meters of water and loss of head due to friction in the draft tube is equal to 0.2x velocity head at outlet of the tube, find:
A Pressure head is inlet and efficiency of the draft tube.(10 marks) 6 (a) A centrifugal Pump is running at 1000 rpm. The outlet vane angle of the impeller is 45° and the velocity of flow at the outlet is 2.5 m/s. The discharge through the pump is 200 lit/s when the pump is working against a total head of 20m. If the inanometric efficiency of the pump is 80% determine the outer diameter of the impeller and the width of the impeller at outlet.(10 marks) 6 (b) Explain with neat sketch the construction and operation of Hydraulic Ram.(10 marks)