Cochin University of Science and Techology (CUST) 2005-5th Sem B.Tech Civil Engineering ,, Fluid Mechanics II - Question Paper

BTS(C) - V - (S) - 05 - 042 (E)

CE 505 (A) FLUID MECHANICS II

(2002 Admissions)

III    a) What are the basic assumptions in gradually varied flow?    (4)

b)    Draw the flow profiles in steep slope channels.    (6)

c)    A trapezoidal channel having bottom width 6m, side slopes - 2 horizontal to 1 vertical and bottom slop 0.0016, carries a discharge of 10m³/sec. A weir placed across the channel backs up the water to a depth of 2m. Calculate how far upstream the depth

is 1.5m. Take N=0.025.    (10)

OR

IV    a) Explain the direct integration method and Bressep method to find the length of flow

profiles.    +    (8)

b)    Starting from first principles derive equations for the slope of the water surface in gradually varied flow with respect to (i) channel bed,, (ii) horizontal.    (5)

c)    A rectangular channel 7.5 m wide has a uniform depth of flow of 2m and has a bed slope of 1 in 3000. If due to weir constructed at the downstream end of the channel, water surface at a section is raised by 0.75m, determine the water surface slope with respect to horizontal at this section. Assume mannings N^s=0.02    (7)

V    a) what are the practical applications of a hydraulic jump.    (5)

b)    Derive an expression for the depth after the hydraulic jump in a rectangular channel. (6)

c)    In a rectangular channel, the loss of energy in a hydraulic jump is 4.25m. The froude number before the jump is 7.5. Find(i) Discharge per metre width of channel

(ii) The depths before and after the hydraulic jump and (iii) Percentage loss of

energy due to the jump.    (9)

OR

VI    a) What are the effects of different types of jump in the design of stilling basin.    (6)

b)    Derive an equation for the celerity of a wave.    (6)

c)    A rectangular channel 4m wide carries a discharge of 12m³/sec at a depth of 2m.

Calculate the height and velocity of a surge produced when the flow is suddenly

stopped completely by the full closure of a sluice gate at the downstream end.    (8)

VII    a) A jet has a direct impact on a series of flat vanes mounted over the periphery of a large

b) A pelton wheel has to be designed for the following data: Power to be developed = 8000 hp.

Speed = 550 rpm

Ratio of jet diameter to wheel diameter =

10

Overall efficiency = 85%

Find the number of jets: diameter of the jet: diameter of the wheel and the quantity of water required.    (10)

OR

VIII    a) Derive an expression for the specific speed of a turbine.    (6)

c)    A Kaplan turbine produces 80000 HP under a head of 25m with an overall efficiency of 90%. Taking the value of speed ratio as 1.6, flow ratio as 0.5 and the

hub diameter as 0.35 times the outer, find the diameter and speed of the turbine.    (8)

IX    a) Explain with neat sketches the working of a single stage centrifugal pump.    (8)

c)    A centrifugal pump of the radial type delivers 5000 litres per minute against a total head of 38m, when running at a speed of 1450 rpm. If the outer diameter of the impeller is 30cm and its width at the outer periphery is 1.3 cm, find the vane angle

OR

X    a) Explain the functions of air vessels in a reciprocating pump.    (6)

b)    Show that the maximum inertia head in a reciprocating pump without air vessel is

I A

g a

c)    A single acting reciprocating pump has a plunger diameter 50cm and a stroke of 40cm. If the speed of the pump is 60 rpm and coefficient of discharge is 0.97,

determine the percentage slip and actual discharge of the pump.    (7)

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Attachment: cochin-university-of-science-and-techology--cust--2005-b-tech-civil-engineering-36858-1.pdf

Earning:   Approval pending.