# Total Pressure BC for High-speed compressible flow - erroneous activation conditions

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 August 5, 2019, 17:14 Total Pressure BC for High-speed compressible flow - erroneous activation conditions #1 New Member   A. Z. Join Date: Jan 2019 Location: France Posts: 3 Rep Power: 6 Hello, Trying to derive the totalPressure boundary condition for a specific use, I found that the conditions for the selection between transonic and supersonic regimes for High-speed compressible flow are not consistent with the aerodynamic definition of these regimes. These conditions are associated with \gamma (specific heat ratios), where they should depend on the speed at least (Mach number). See the script here below from: fields/fvPatchFields/derived/totalPressure/totalPressureFvPatchScalarField.C (OpenFOAM-5.x) ################################################## ########################## Code:  else { // High-speed compressible flow const fvPatchField& psip = patch().lookupPatchField(psiName_); if (gamma_ > 1) { scalar gM1ByG = (gamma_ - 1)/gamma_; operator== ( p0p /pow ( (1.0 + 0.5*psip*gM1ByG*(1.0 - pos0(phip))*magSqr(Up)), 1.0/gM1ByG ) ); } else { operator==(p0p/(1.0 + 0.5*psip*(1.0 - pos0(phip))*magSqr(Up))); } } ################################################## ######################### This may induce errors, any comment or suggestion regarding the way to proceed with this? Thanks. Zi Aun. Last edited by Zi_Aun; August 5, 2019 at 20:16. Reason: Add of the traditional "Hello"

 Tags gamma, totalpressure bc