[sahmed]

Dear foamers
I am sure lots of you are using totalPressure boundary condition in your simulations. I am trying to use it as my outlet boundary condition for pressure since I have possibility of backflow and in that case, the totalPressure bc is numerically most stable one along with pressureInletOutletVelocity boundary for velocity.
In the manual, it is mentioned that the data to specify with totalPressure is only p0, but I saw that there are a number of parameters speficied, e.g. gamma, phi, rho, U etc. Could anyone PLEASE tell me what values I have to specify along with totalPressure boundary condition?

[sahmed]

I used the parameters of the totalPressure from the top 'atmosphere' boundary of the dam breaking tutorial. But it always gives me diverged solution- 'floating point exception'. Can anyone please help me regarding the parameters to be specified for this totalPressure boundary??

[TobM]

Look here for settings:
https://cpp.openfoam.org/v4/a02729.html

In older versions of OF you had to specify more than just p0, the totalPressure BC was simplified.

[sibo]

Dear TobM,

I have a question about the ganma in totalpressure Bc setting. I thought the value of gamma should be determined by the temperature of air not the mach number. but from the page you provided, for transonic flow the gamma is 1. Does that mean no matter what the initial condition is, as long as the flow is transonic, the gamma should be 1 in the totalpressure Bc?

Also, it said for compressible subsonic flow, there is no need to input gamma, but when i delete the gamma for my subsonic flow case, there will be an error"gamma undefined".

Could you help me with these questions? Thanks a lot!!!!!!!

[calf.Z]

I am also interested in the parameters in this boundary setting. Can you give some explains?

Thank you very much.