Brake Horsepower

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Brake horsepower, abbreviated as BPH, is the engine's horsepower required to overcome the loss in power caused by the pump.

 

Brake Horsepower formulas

\(\large{ BHP = \frac{ 100 \; Q \; h_t }{ 3960 \; \eta }  }\)   
\(\large{ BHP = \frac{ Q \; h_t  \; SG }{ 3960 \; \eta }  }\)  
\(\large{ BHP = \frac{ \tau \; RPM }{ 5252 }  }\)  
\(\large{ BHP = \frac{ WHP }{ \eta_p }  }\)  

Where:

 Units English Metric
\(\large{ BHP }\) = brake horsepower \(\large{\frac{lbf-ft}{sec}}\) \(\large{\frac{Btu}{s}}\)
\(\large{ Q }\) = flow rate \(\large{\frac{ft^3}{sec}}\) \(\large{\frac{m^3}{s}}\)
\(\large{ \eta_{tp} }\)  (Greek symbo; eta) = efficiency dimensionless
\(\large{ \eta_p }\)  (Greek symbol eta) = pump efficiency dimensionless
\(\large{ RPM }\) = revolutions per minute \(\large{\frac{rev}{min}}\) \(\large{\frac{rev}{min}}\)
\(\large{ \tau }\)  (Greek symbol tau) = torque \(lbf-ft\) \(N-m\)
\(\large{ h_t }\) = total head \(ft\) \(m\)
\(\large{ SG }\) = specific gravity dimensionless
\(\large{ WHP }\) = water horsepower \(\large{\frac{lbf-ft}{sec}}\) \(\large{\frac{Btu}{s}}\)

 

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Tags: Power Equations Horsepower Equations