Pressure Drop due to Friction

Fanning friction factor (\(f\)): \[f = \frac{\tau_w}{\rho v^2/2}\] Pressure drop (\(\Delta P\)) due to friction for flow through a pipeline is given by \[\Delta P = \frac{2fL\rho v^2}{D} \tag*{(1)}\]

\(D\) = diameter of pipe
\(v\) = fluid velocity
\(L\) = length of pipe over which pressure drop is measured
\(\rho\) = density of fluid
\(f\) = friction factor

The above equation is also known as Darcy-Weisbach equation. It should be noted that the ‘\(f\)’ used here is Fanning friction factor.