[tangd]

I looked into the code of totalPressure and guess that the equation for total pressure is only applied to incompressible fluid flow. The equation I copied from totalPressureFvPatchScalarField.C is:

operator==(p0_/(1.0+0.5*psi*(1.0-pos(phip))*magSqr(Up)));

or

operator==(p0_-0.5*(1.0-pos(phip))*magSqr(Up));

That could be part of the reason why my simulation with sonicTurbFoam failed. So I think when using compressible solvers, atmosphere boundary type could not be used. Is my conclusion correct?

In my opinion, the corresponding total pressure equation for compressible flow should be derived from second law and the enthalpy equation dh = cp(T)dT, if Cp is not constant. So the mathematical expression for ptot should be more complicated. Maybe I'm wrong, but I want to confirm this information. Thanks!