Hydraulic Efficiency of a pump

The Hydraulic Efficiency of a pump is the ratio of the useful hydrodynamic energy in the fluid to the energy supplied to the rotor of the pump.

Hydraulic Efficiency = Useful hydrodynamic Energy / Energy Supplied to the Rotor of the pump

The hydraulic efficiency is related to the number of vanes in centrifugal pumps and the depth of the channels. Optimizing the design of the impeller such that the friction between the liquid and the impeller surface is minimum can also improve hydraulic efficiency.