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III Semester B.E. (Civil Engg.) Degree Examination, Dec. 2014/Jan. 2015 (2K6 Scheme) CE – 303 : FLUID MECHANICS AND HYDRAULIC MACHINERY Time : 3 Hours

Max. Marks : 100

Instructions : 1) Part A is compulsory. 2) Answer five full questions from Part B and Part C, selecting atleast one question from each Part. PART – A 1. a) Write equations for determination of capillary rise and fall of a liquid in a small glass tube. b) With neat line diagram mention the classification of pressure. c) Explain fluid pressure at a point with fig. d) Explain uniform and non uniform flow. e) With neat figure write the component parts of orificemeter. f) Explain Hydraulic coefficients. g) Distinguish between notches and weirs. h) Write a note on specific speed of a Turbine. i) List different classification of Turbine. j) List different types of similarities and explain any one of them.

(2×10=20)

PART – B 2. a) With a neat figure state and prove Pascals law.

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b) A triangular plate having base 11.25 m and altitude 1.8 m lies in a vertical plane. The vertex of the plate is at top and lies 1.2 m below free surface of water. Base of the plate is horizontal. Determine total pressure and position of centre of pressure.

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P.T.O.

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3. a) With a neat figure derive continuity equation for three dimensional flow in cartesian firm.

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b) The velocity components in a two dimensional fluid flow are u = 2xy, v = b2 + x2 – y2 i) Is the flow possible ? ii) Is the flow rotational or irrotational ? iii) If flow is irrotational determine velocity potential function iv) Determine corresponding stream function. 4. a) With a neat figure explain dynamic viscosity and kinematic viscosity of a fluid. Obtain the equations and write units for the same in MKS and SI system.

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b) Explain surface tension phenomenon with fig.

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c) A clean tube of internal diameter 3 mm is immersed in a liquid with coefficient of surface tension 0.48 N/m, angle of contact in 130°. Determine rise of liquid level in tube by taking density of liquid as 13600 Kg/m3.

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PART – C 5. a) State and prove Bernoullis equation with neat figure by first deriving Eulers equation. b) A venturi meter 150 mm × 75 mm is installed in a horizontal pipe line of 150 mm diameter carrying oil of S.G. 0.9. The mercury level difference in the U-Tube manometer connected to inlet and the throat is 175 mm. Determine rate of flow through pipe. 6. a) Define Cc, Cv and Cd for an orifice and derive the relation between them.

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b) Derive an expression for discharge over a rectangular notch.

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c) Oil flows through a 25 mm dia pipe at the rate of 3 liters/sec. The jet strikes away 1.5 m away at 120 mm below centre line of orifice. Determine Cc, Cv and Cd.

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7. a) List the comparison between impulse turbine and reaction turbine.

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b) With neat fig. explain the performance of Pelton wheel turbine.

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8. a) Differentiate between radial flow and parallel flow turbines. Give examples.

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b) What are ranges of specific speed of a Pelton, Francis and Kaplan Turbine ? Also explain what is meant by specific speed.

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c) With neat fig, explain working principle of centrifugal pump.

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9. a) The pressure drop ( Δ P) in a venturimeter varies with fluid density ( ρ ), velocity ( ν ) at inlet, diameter at inlet D, and diameter of the thread d using Buckingham’s π theorem, obtain the relationship for pressure drop. 10 b) A model of venturimeter tested with water at 20° C. Shown a 5 KPa pressure drop when the approach velocity is 4 m/sec. A geometrically similar venturimeter is to be used to measure petrol of man desentily 680 Kg/m3 at 20° C and flow rate of 9 m3/min. Determine inlet diameter if the pressure drop is to be 15 KPa.

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