Kinetic energy flux of a uniform jet
= Kinetic energy flux of a uniform jet
{title2=$\dot K=\rho Au^3/2$}
A steady uniform incompressible jet has <mass flow rate> $\rho Au$, <momentum flux> $\rho Au^2$ and kinetic-energy flux $\rho Au^3/2$. These use the area and velocity at the same cross section. A nonuniform profile instead requires integrating powers of local speed; using mean speed in a cubic flux without a profile correction is generally wrong.