Specific internal energy
= Specific internal energy
{title2=$e$}
Specific <internal energy> is <internal energy> per unit mass. For a <perfect gas> with constant <specific-heat ratio>, $e=p/[(\gamma-1)\rho]$. Its material balance is $\rho De/Dt=-p\nabla\cdot\mathbf u+Q$, where $Q$ is <heat> supplied per unit volume per unit time.