Mechanical Efficiency

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Mechanical efficiency, abbreviated as \( \eta_m \)  (Greek symbol eta), a dimensionless number, is the ratio of theoretical power the pump needs to operate to the actual power delivered to the pump itself.

 

Mechanical Efficiency Formulas

\(\large{ \eta_m = \frac{ PSI \; 100 }{ TT } }\) (motor (pressure differential PSI) )
\(\large{ \eta_m = \frac{ PSI \; 100 }{ TP } }\) (pump (gauge pressure PSI) ) 

Where:

\(\large{ \eta_m }\)  (Greek symbol eta) = mechanical efficiency

\(\large{ CIR }\) = cubic inch per revolution

\(\large{ PSI }\) = gauge pressure in pounds per square inch

\(\large{ PSI }\) = pressure differential across motor in pounds per square inch

\(\large{ TP }\) = theoretical pressure

\(\large{ TT }\) = theoretical torque

\(\large{ \tau }\)  (Greek symbol tau) = torque

Solve for:

\(\large{ TT = \frac{ CIR \; PSI }{ 6.28 } }\) (motor)
\(\large{ TP = \frac{ \tau \; 6.28 }{ CIR } }\)  (pump) 

Tags: Equations for Efficiency