An Impulse turbine with a head m and an efficiency η of 85 % develops a power kW. The runner is driven by two water jets at 400 rpm. The losses in the nozzle are 3 % and the friction coefficient of the blades is .85. The water spreads at 170° from the runner blades. The velocity ratio between the water jet and the runner velocity is r = Rω / uj = 0.46. Neglecting the losses in the pipe, determine:
(a) the water jet diameter.
(b) the hydraulic efficiency of the turbine.