Hagen–Poiseuille Law

Written by Jerry Ratzlaff on . Posted in Properties

Hagen–Poiseuille Law (Poiseuille Law, Poiseuille Equation or Hagen–Poiseuille Equation) gives the pressure loss in a fluid flowing through a long cylindrical pipe.

Abbreviated as \(Q\)

formula

\(\Delta p = \frac { 8 \mu l Q }{ \pi r^4 }   \)

\(\Delta p = \frac { 128 \mu l Q }{ \pi d^4 }   \)

Where:

\(\Delta p\) = pressure loss

\(\mu\) = dynamic viscosity

\(l\) = length

\(Q\) = volumetric flow rate

\(\pi \) = Pi

\(r\) = radius

\(d\) = diameter