Hall Ticket No:
Question Paper Code: A3110
VARDHAMAN COLLEGE OF ENGINEERING
(AUTONOMOUS) B. Tech IV Semester Regular/Supplementary Examinations, May 2018
(Regulations: VCE-R15) HYDRAULICS AND HYDRAULIC MACHINES
(Civil Engineering) Date: 11 May, 2018 FN
Time: 3 hours
Max Marks: 75
Answer ONE question from each Unit
All Questions Carry Equal Marks
Unit I
1.
Briefly explain different types of flow in channels.
7M
A trapezoidal channel has side slopes of 1 horizontal to 2 vertical and the slope of the bed is 1 in 1000. The area of the section is 42m2. Determine the dimension of the section if it is most economical. Also determine the discharge of the most economical section if C=60.
8M
2.
Find the velocity of flow and rate of flow of water through a rectangular channel of 6m wide and 3m deep, when it is running full. The channel is having bed slope as 1 in 2000. Take Chezy's constant C=55.
8M
Find the discharge through a trapezoidal channel of width 8m and side slop 1 horizontal and 3 vertical. The depth of flow of water is 2.4m and chezy constant is 50. The slope of bed of channel is 1 in 4000.
7M
Unit II
3.
State and explain Buckingham's pi theorem.
7M
A 1:50 spillway model has a discharge of 1.25m3/s. What is the corresponding prototype discharge? If a flood phenomenon takes 12 hours to occur in the prototype, how long should it take in the model?
8M
4.
Explain the similarities that must exist between prototype and model.
6M
Explain the significance of:
i. Weber number
ii. Euler's number
iii. Reynolds number
9M
Unit III
5.
Derive an expression for torque exerted on a wheel with radial curved vanes.
8M
A jet of water 75mm in diameter having velocity of 20m/s strikes a series of the flat plates arranged around the periphery of a wheel such that each plate appears successively before the jet. If the plates are moving at a velocity of compute the force exerted by the jet on the plate, the work done per second on the plate and the efficiency of the jet.
7M
6.
Show that the force exerted by a jet on semi-circular curved vane (when the jet strikes at its centre) in the direction of motion of the jet is more than as that of the force on a flat plate.
8M
A 75mm diameter jet has a velocity of 35m/s. It strikes a moving curved vane in the same direction at 20m/s. The deflection angle of the vane is 150°. Assuming no friction, calculate the X and Y components of the force exerted by the water on the vane.
7M
Cont…2
2
Unit IV
7.
Draw general layout of a hydro-electric power plant when the type of turbine is:
i. Impulse turbine
ii. Reaction turbine
8M
A Kaplan turbine produces 60,000Kw under a net head of 25m with an overall efficiency of 90%. Taking the value of speed ratio Ku as 1.6, flow ratio as 0.5 and the hub diameter as 0.35 times the outer diameter, find the diameter and speed of the turbine.
7M
8.
With the help of a neat sketch explain various components in Francis turbine.
8M
Explain draft tube theory and derive an expression for the efficiency of a draft tube.
7M
Unit V
9.
Define cavitation and discuss the effects of cavitaiton.
5M
Find the power required to drive a centrifugal pump which delivers 40litres of water per second to a height of 20m through a 150mm diameter 100m long pipeline. The overall efficiency of pump is 70% and Darcy's f=0.06 for the pipeline. Assume inlet losses in suction pipe equal to 0.33m.
10M
10.
Define the following and write corresponding equations:
i. Manometer efficiency
ii. Volumetric efficiency
iii. Mechanical efficiency
iv. Overall efficiency
8M
A centrifugal pump delivers water at the rate of 1800lpm, to a height of 20m, through a 0.1m diameter, 80m long pipe. Find the power required to drive the pump, if the overall efficiency is and Darcy's friction factor=0.02.
7M