Kinetic energy correction factor
= Kinetic energy correction factor
{title2=$\alpha=\frac{\int_Au^3\,dA}{A\overline u^3}$}
For unidirectional flow through area $A$ with mean speed $\overline u$, the outgoing kinetic-energy flux is $\tfrac12\rho A\alpha\overline u^3$, where $\alpha=(A\overline u^3)^{-1}\int_Au^3dA$. Cubing the mean speed generally differs from averaging the cube. A uniform profile has $\alpha=1$; circular laminar <Hagen-Poiseuille flow> has $\alpha=2$.