Code No. 2010 / O

FACULTY OF ENGINEERING B.E. 3/4 (Civil) I-Semester (Old) Examination, November / December 2012 Subject : Fluid Mechanics - II Time : 3 Hours Note: Answer all questions of Part - A and answer any five questions from Part-B. PART – A (25 Marks) 1. State the significance of pressure distribution in channel cross-section.

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2. Give in detail with sketches, the classification of flow profiles.

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3. Define displacement thickness.

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4. What is the significance of characteristic curves of turbines?

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5. What is critical period of a pipe line?

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6. Mention the applications of Bukingham- theorem.

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7. What do you understand by backwater effect?

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8. Define manometric efficiency and overall efficiency.

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9. Give in detail the classification of turbines.

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10. State the uses of draft tube.

(2) PART – B (5x10=50 Marks)

11.(a) Derive an expression for the most economical section for a trapezoidal channel section half of the top width is equal to one of the sloping side. (b) A rectangular channel is 6m wide and 1.50m deep. If the bed of the channel is laid at a slope of 1 in 5000, find the velocity and the discharge. Take C=50. 12.(a) A sluice spans a channel of rectangular section 15m wide and has an opening 0.60m wide and discharge 40m3/s of water. If a hydraulic jump is formed on the downstream side of the sluice, determine the probable height of the crest above the upper edge of the sluice. Find also the loss of energy head due to the jump. (b) Explain in detail the significance and procedure of direct step method. 13.(a) Define water hammer. Derive an expression for pressure rise due to sudden valve closure and gradual valve closure. 2

u 3y  y  (b) Assuming the velocity distribution in the boundary layer as     determine U   

the thickness of the boundary layer and the shear stress intensity 0.8m from the whole leading edge and the drag force on one side of a plate 1.25m long and 1.20m wide placed in water of velocity 0.30m/sec. Take  as -0.001 Ns/m2 for water. 14.(a) Explain different types of models and their scale ratios. (b) The discharge characteristics of a spillway 17.5m long are to be determined. It is designated to discharge 155 cumec at a head of 4.0m. The supply available in the laboratory is 40 lt/sec. Calculate : (i) prototype – model length ratio (ii) length of model spillway and (iii) Head over the model spillway ..2

Code No. 2010 / O ..2..

15.(a) A centrifugal pump delivers water against a net head of 14.5m at the design speed of 1100 rpm. The vanes are curved backwards at an angle of 30o with the periphery. The impeller diameter is 30cm and outer width 5cm. Determine discharge of the pump. Take manometric efficiency as 95%. (b) State the advantages and disadvantages of a Francis Turbine over a Pelton wheel. 16.(a) What points should be considered while selecting right type of hydraulic turbines for hydro electric power plants? (b) What do you understand by critical depth of an open channel when the flow in it is not uniform? Also state the conditions under which uniform and non-uniform flows are produced. 17. Write short notes on the following: (a) Positive and negative surges in an open channel (b) Boundary layer growth and separation *****