Hagen–Poiseuille Equation

Written by Jerry Ratzlaff on . Posted in Fluid Dynamics

Hagen–Poiseuille equation, also called Hagen–Poiseuille Law, Poiseuille equation, or Poiseuille law, gives the pressure loss in a fluid flowing through a long cylindrical pipe.

 

Hagen–Poiseuille Equation formula

\(\large{ \Delta p = \frac { 8 \; \mu \; l \; Q }{ \pi \; r^4 }   }\) 
Symbol English Metric
\(\large{ \Delta p }\) = pressure loss \(\large{\frac{lbf}{in^2}}\)  \(\large{Pa}\) 
\(\large{ \mu }\)  (Greek symbol mu) = dynamic viscosity \(\large{\frac{lbf-sec}{ft^2}}\) \(\large{Pa-s}\)
\(\large{ l }\) = length of pipe \(\large{ft}\) \(\large{m}\)
\(\large{ \pi }\) = Pi \(\large{3.141 592 653 ...}\)
\(\large{ r }\) = pipe inside diameter \(\large{in}\) \(\large{mm}\)
\(\large{ Q }\) = volumetric flow rate \(\large{\frac{ft^3}{sec}}\) \(\large{\frac{m^3}{s}}\)

 

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Tags: Pressure Equations Pipe Equations