Consider a pumpturbine that operates both as a pump and as a turbine. Under conditions in which

Question:

Consider a pump–turbine that operates both as a pump and as a turbine. Under conditions in which the rotational speed ω and the volume flow rate V̇ are the same for the pump and the turbine, verify that turbine specific speed and pump specific speed are related as

Nst = NSV Nsp St = mturbine H pump H turbine Nsp(nturbine) 5/4 (pump) 3/4 bhp pump 3/4 bhpurbine