Engineering Calculator
Professional engineering calculations for pressure, torque, stress, force, and more. Precision tools for engineers and technical professionals.
Calculates the hydraulic power required to pump a fluid, and the shaft power needed from the motor accounting for pump efficiency.
Hydraulic power: P_hydraulic = ΟgQH (W). Shaft power: P_shaft = P_hydraulic / Ξ·_pump. Motor power: P_motor = P_shaft / Ξ·_motor. Total efficiency: Ξ·_total = Ξ·_pump Γ Ξ·_motor (typically 0.55β0.75).
The Reynolds number β determining whether flow is laminar or turbulent β was derived by Osborne Reynolds in 1883 using dye injected into glass pipes. His original experimental apparatus is still on display at the University of Manchester.
Sizing a pump at exactly the required duty point. Pump efficiency falls at off-design flows β a pump sized right at BEP (best efficiency point) operates poorly if system resistance varies. Select pump so normal duty is 80β110% of BEP flow.