Download AKTU B-Tech 4th Sem 2014-15 Electrical and Electronics Engineering Materials Question Paper

Code: 20A03301

B.Tech II Year I Semester (R20) Regular Examinations November 2021

FLUID MECHANICS

(Civil Engineering)

Time: 3 Hours                                                                                                            Max. Marks: 70

Note: Answer all questions. All questions carry equal marks.

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1. a) Define the following terms: Density, Specific weight, Specific volume, Specific gravity of a fluid.

   b) A 450 mm diameter shaft rotates at 200 rpm in a bearing of length 150 mm. The clearance between the shaft and bearing is 0.2 mm and the viscosity of lubricant oil is 1.0 poise. Determine the power absorbed in the bearing.

   OR

2. a) Derive the expression for total pressure and center of pressure for a vertically immersed plane surface.

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   b) A circular plate 3.0 m diameter is submerged in water, with its greatest and least depths below the surface being 4 m and 1.5 m respectively. Determine the total pressure on one face of the plate and the location of the center of pressure.

3. a) Define the equation of continuity. Obtain an expression for continuity equation for three-dimensional flow.

   b) The velocity potential function is given by ? = 5?, Calculate the velocity components at the point (4, 5). Also, verify whether the function represents a possible case of fluid flow.

   OR

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4. a) State Bernoulli's theorem for steady flow of an incompressible fluid. Derive an expression for it and state the assumptions made.

   b) A pipe of diameter 400 mm carries water at a velocity of 25 m/s. The pressures at the points A and B are given as 29.43 N/cm² and 22.563 N/cm² respectively while the datum head at A and B are 28 m and 30 m. Find the loss of head between A and B.

5. a) What is meant by Hydraulic Grade Line (HGL) and Total Energy Line (TEL)? Explain their significance.

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   b) Water is flowing through a horizontal pipe of diameter 200 mm at a velocity of 3 m/s. Find the loss of pressure in 15 m length of pipe if ? = 0.01.

   OR

6. a) Derive Darcy-Weisbach equation for head loss due to friction in pipe.

   b) A crude oil of viscosity 0.9 poise and relative density 0.9 is flowing through a horizontal circular pipe of diameter 80 mm and length 15 m. Calculate the difference of pressure at the two ends of the pipe, if the rate of flow of oil is 8 liters/sec.

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7. a) Explain the terms: Boundary layer, Boundary layer thickness, Displacement thickness, Momentum thickness and Energy thickness.

   b) Determine the thickness of the boundary layer at the end of a plate 2 m long and 0.8 m wide when placed in water flowing with a velocity of 0.2 m/s. Calculate the drag force on one side of the plate if the viscosity of water is 0.001 N.s/m².

   OR

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8. a) What do you understand by the terms: Lift, Drag, Coefficient of Lift and Coefficient of Drag?

   b) A kite weighing 2.5 N has an effective area of 0.75 m². It is maintained in air at an angle of 10° to the horizontal. The tension in the string is 25 N when the wind is blowing at 40 km/hr. Find the coefficients of lift and drag. Take density of air as 1.21 kg/m³.

9. a) What do you mean by dimensional homogeneity? Explain with examples.

   b) The efficiency ? of a fan depends on density ?, the dynamic viscosity ? of the fluid, angular velocity ?, diameter D of the rotor and the discharge Q. Express ? in terms of dimensionless parameters.

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   OR

10. a) Define the following dimensionless numbers: i) Reynolds number ii) Froude's number iii) Euler's number iv) Mach number and v) Weber number. Explain their physical significance.

    b) A pipe of diameter 1.5 m is required to transport 25 m³/s of water. Tests were conducted on a 15 cm diameter pipe using water at 20°C. Find the velocity and rate of flow in the model. Take viscosity of water at 20°C = 0.01 poise.

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