POKHARA UNIVERSITY

Level: Bachelor Semester – Spring Year : 2010Programme: BE Full Marks : 100

Pass Mark : 45Course: Hydropower Time : 3 hrs

Candidates are required to give their answers in their own words as far as practicable.The figures in the margin indicate full marks.Attempt all the questions.

1. a. On what principle the continuity equation is based on? State and derive the continuity equation for a pipe flow.

b. A pipeline ABC 180 m long is laid on a upward slope of I in 60. The length of the portion AB is 90m and its diameter is 150mm. At B the pipe section suddenly enlarges to 300 mm diameter and remains so for the remainder of its length BC, 90 m. A flow of 0.05 m3/s is pumped into the pipe at its lower end A and is discharged at the upper end C into a closed tank. The pressure at the supply end A is 140 KN/m2 than find the pressure at the discharge end C.

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2. a. What are the differences between friction factor and fanning friction factor? Describe it. And also derive friction factor in head loss in pipe.

b. Using 30 years data and Gumbel’s method the flood magnitudes for return periods of 100 and 50 years for a river found to be 1200 and 1060 cusec respectively. Estimate the magnitude of a flood with a return period of 500 years.

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3. a. What are the selection criteria of turbine? Describe it.b. Describe construction of Kaplan turbine with the help of sketch.

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4. a. Describe working principle of centrifugal pump with neat sketch.

b. Water is supplied to a town of 400,000 inhabitants. The reservoir is 6.4 Km away from the town and loss of head due to friction in pipe line is measured as 15 m. Calculate size of supply main if each inhabitants consumes180 lit of water per day and half of the daily supply is pump in 8 hr.(f = 0.030)

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5. a. Why it is necessary to dissipate energy when water is spilled out 7

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through the overflow dam? Explain different types of spillways with neat sketch.

b. What is meant by hydraulic jumps? Describe different types of surge tanks with necessary sketches.

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6. a. Describe the methods used to estimate the missing rainfall data at a station. How would you determine optimum number of rain gauges to be installed in a given catchments?

b. A storm with 20 cm of precipitation produced a surface runoff of 11.6 cm. Estimate the ø-index of the storm if the temporal distribution of rainfall is as follows:

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Duration(hr) 1 2 3 4 5 6 7 8

Incremental rainfall per hour(cm)

0.8 1.8 3.0 4.6 3.6 3.2 2.0 1.0

7. Write short notes on any two:c. Continuity equationd. U-Tube manometere. Types of concrete and fill dams

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