[keda xu]

SonicFoam is applied.

Max Velocity is defined in fvSolution file “UMax”, but the results showed that the velocity limit did not work.

Courant number limit is defined in ControlDict file, but it did not work either. The way how to limit Courant number is from the solutions in this forum。

Anyone knows how to fix these problems?

[Pappelau]

I never used SonicFoam, but for other Solvers its possible to limit U in the constant/fvOptions file. If you use Foam 9 fvOption is splitted in two parts.

limitU
    {
        type            limitVelocity;
        active          yes;

        selectionMode   all;
        max             40;
    }

[keda xu]

Thanks, Lukas, I created fvoptions file in constant and it works. Do you know how to limit courant number?

[Pappelau]

Courant number can be limited only for transient runs and then it is limited through the controlDict in system

add this :

adjustTimeStep yes;

maxCo           0.25;
#maxAlphaCo      0.05;  #is used for two phaseflows
maxDeltaT       0.1; # upper limit