Question

A 1-m diameter penstock is 10-km long and carries water to an impulse turbine. If the turbine/generator is 83 percent efficient, what power can be extracted if the elevation difference between the reservoir and the nozzle is 650 m. The jet (nozzle) diameter is 16 cm.

Answer 1

Explanation:

Difference in diameter = (1 - 16/100)m = (1.00 - 0.16) = 0.84m

∴ Radius, r = 0.84/2 = 0.42m

Volume of pipe, V = πr²h = 22/7 X (0.42)² X 10,000 (where height, h = 10km or 10,000m)

V = 5544m³ or 5.54 Liters (in capacity)