Entropy advection equation
= Entropy advection equation
For an adiabatic ideal fluid, entropy is materially conserved away from shocks: $Ds/Dt=0$. For a perfect gas this is equivalent to $Dp/Dt+\gamma p\nabla\mathbin\cdot\mathbf u=0$.
= Entropy advection equation
For an adiabatic ideal fluid, entropy is materially conserved away from shocks: $Ds/Dt=0$. For a perfect gas this is equivalent to $Dp/Dt+\gamma p\nabla\mathbin\cdot\mathbf u=0$.