Written by Jerry Ratzlaff on . Posted in Pump

Suction head coefficient, abbreviated as $$C_{NPSH}$$, a dimensionless number, is the angular velocity of the turbomachine shaft and the turbomachine impeller diameter.

 $$\large{ S = \frac{ g \; NPSH }{ \left( \frac{ 2 \; \pi }{ t } \right)^2 \; d^2 } }$$

### Where:

$$\large{ C_{NPSH} }$$ = suction head coefficient

$$\large{ NPSH }$$ = net positive suction head

$$\large{ t }$$ = period

$$\large{ \pi }$$ = Pi

$$\large{ g }$$ = standard gravity

$$\large{ d }$$ = turbomachine impeller diameter