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III Semester B.E. (Civil) Degree Examination, January 2013 (2K11 Scheme) CE 304 : FLUID MECHANICS AND HYDRAULIC MACHINERY Time : 3 Hours

Max. Marks : 100

Instructions : 1) Part – A is compulsory. 2) Answer 5 questions by selecting atleast one from Part – B and Part – C. PART – A I. a) List important properties of fluid. b) For the following properties of fluid, write its units in SI system i) Mass Density ii) Weight density iii) Dynamic viscosity iv) Kinematic viscosity. c) Distinguish between piezometer and manometer. d) Write a neat line diagram for classification of pressure. e) Define total pressure and centre of pressure. f) List types of fluid flow. g) List the assumptions of Bernoullis equation. h) Distinguish between Notcher and weirs. i) Define specific speed of a centrifugal pump. Also write its mathematic expression. j) Explain the term Dimensionally homogeneous equation.

(2×10=20) P.T.O.

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PART – B 2. a) With neat figure obtain an expression for capillary rise and capillary fall.

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b) 2.2 liters of certain liquid weighs 20 N. Determine its specific weight, density and specific gravity.

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c) A plate 0.040 mm from a fixed surface moves at 0.6 m/s and requires a force of 1.50 N/m2 to maintain this speed. Determine fluid viscosity between the plates in Poise.

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3. a) State and prove Pascal’s law with neat figure.

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b) With a neat figure determine total pressure and centre of pressure on a vertically immersed plane surface.

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c) A circular plate 3.0 m dia is immersed in water in such a way that, its greatest and least depths below the free surface are 4 m and 1.50 m respectively. Determine the total pressure on one face of the plate and position of centre of pressure.

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4. a) With a neat figure obtain an expression for continuity equation for three dimensional flow.

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b) Define velocity potential function and stream function. Also write its properties.

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c) Calculate the unknown velocity component so that they satisfy continuity equation for u = 2x2 + 2xy, v = ? w = z3 – 4xz – 2yz.

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PART – C 5. a) With a neat figure derive Euler’s equation and then obtain Bernoullis equation. b) The inlet and throat diameters of a horizontal venturimeter are 30 cm and 20 cm respectively. The liquid flowing in the pipe is water. The pressure intensity at inlet is 13.734 N/cm2, whereas the vacuum pressure head at the throat is 37 cm of mercury. Determine discharge. Assume 4 percent of differential head is lost between inlet and throat. Also determine coefficient of discharge for venturimeter.

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6. a) With figure explain determination of Hydraulic coefficients experimentally.

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b) List advantages of Triangular notch over rectangular notch.

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c) Obtain an expression to determine rate of flow through a triangular notch.

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7. a) Obtain an expression for the force exerted by a jet of water on a fixed vertical plate in the direction of the jet.

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b) List and explain classification of turbines.

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c) With figure explain working of a centrifugal pump.

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8. a) State and explain Buckingham’s π theorem.

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b) Define and derive the expressions for the following : i) Froude’s number ii) Reynold’s number.

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c) A spillway model is constructed to a scale of 1 : 36. The length of spillway in prototype is 60 m and the discharge over it for the head of 4 m is 1298 m3/s. Determine discharge over the model. Also find the time scale ratio for the model.

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9. a) Derive an expression for the force exerted on an unsymmetrical moving curved vane, when the jet strikes the vane tangentially at one of its tips. Draw velocity triangles.

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b) Prove that the maximum efficiency developed in the case of jet striking a series of flat vanes mounted on the periphery of a wheel will be 50 %.

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