express efficiency of a centrifugal pump in terms of torque

express efficiency of a centrifugal pump in terms of torque T, rpm N, pump head H, pump capacity Q and densisity of the fluid

Solution

Pump Efficiency: The term pump efficiency is used on all types of pumps to describe the ratio of power supply to the drive shaft against water horsepower.

Pump Efficiency p =( Water horse power/Required power) x 100%

or
Pump Efficiency p = (Q x H x x g)/ x T
where: Q = capacity (m³/s)
H = total head/pressure (m)
= fluid density (kg/m³)
g = acceleration due to gravity (m/s²)
= shaft angular velocity (rad/s)
T = shaft torque (Nm)