Question

A double jet Pelton wheel operates under a 40 m head and has to develop 735 kW when running
at 450 rpm. The overall efficiency is given as 85% and the coefficient of velocity is C, = 0.98.
Find the total flow rate of water supplied to the wheel.
(a) Q = 4.204 m/s
(b) Q=2.204 m/s
(C) Q=1.204 m/s
(d) Q = 20.204 m/s

Answer 1

23.335 m/s

Explanation:

• Water velocity from Nozzle in Peltonwheel is given by

                               $V = C_v\sqrt{2gH}$

• Where V is velocity, Cv is coeff velocity, H is the net head

• Given Cv = 0.98, H = 40m, efficiency = 85%
• Thherefore V = $0.85 \times 0.98 \times \sqrt{2 \times 9.8 \times 40}$ = 23.335 m/s