A model pump (Fig. P12.32) delivers 80°C water at a speed of 2400 rpm. It begins to cavitate when the inlet pressure pi = 83 kPa absolute and inlet velocity Vi 6 m/s.
(a) Compute the NPSH of the model pump. Neglect losses and elevation changes between the inlet section where pi is recorded and the cavitation region in the pump.
(b) What is the required NPSH of a prototype pump that is four times larger and runs at 1000 rpm?
