Specific enthalpy
= Specific enthalpy
{title2=$h$}
Specific enthalpy is <enthalpy> per unit mass. For a simple compressible fluid of fixed composition, the <first law of thermodynamics> gives
$$
dh=T\,ds+\frac{dp}{\rho},
$$
where $T$ is <temperature>, $s$ is <specific entropy>, $p$ is <pressure>, and $\rho$ is <mass density>. Along an <isentropic flow>, $dh=dp/\rho$. For a <perfect gas> with constant <specific-heat ratio> $\gamma$, $h=\gamma p/[(\gamma-1)\rho]$.