[kaergaard]

Dear Forum.
I have a problem wiith interFoam. With a plane water surface and no flow trough any boundaries I get a flow along the bottom boundary when the mesh elements near the boundary are non-orthogonal. I expected zero velocity everywhere.
The flow velocity increases as time goes and ends up blowing up the computation. I have attatched an image showing the same simulation with slightly different meshes the top one has a maximum non-orthogonality of 65, the middle 35 and the bottom 15 (mesh is made using snappyMesh). The shown time is 0.01 s.
I would like to be able to run the simulaiton with a larger non-orthogonality since this will describe my bottom better. I have tried
nOrthoCorrectors = 5, with no improvement, I have also tried different combinations of schemes for laplace (MUSCL uncorrected, corrected linear, upwind), and div (MUSCL, upwind, linear). Any ideas are most welcome.

Best regards Kasper


My fvSolution file is:
solvers
{
pcorr PCG
{
preconditioner DIC;
tolerance 1e-10;
relTol 0;
};
p PCG
{
preconditioner DIC;
tolerance 1e-10;
relTol 0;
};
pFinal PCG
{
preconditioner DIC;
tolerance 1e-10;
relTol 0;
};
U PBiCG
{
preconditioner DILU;
tolerance 1e-10;
relTol 0;
};
}

PISO
{
pdRefCell 0;
pdRefValue 0;
momentumPredictor yes;
nCorrectors 3;
nNonOrthogonalCorrectors 5;
nAlphaCorr 1;
nAlphaSubCycles 1;
cAlpha 1;
}
fvSchemes:
ddtSchemes
{
default Euler;
}

gradSchemes
{
default Gauss linear;
grad(U) Gauss linear;
grad(alpha) Gauss linear;
}

divSchemes
{
default Gauss linear;
// div(rho*phi,U) Gauss MUSCL;
// div(phi,alpha) Gauss vanLeer;
// div(phirb,alpha) Gauss interfaceCompression;
}

laplacianSchemes
{
default Gauss upwind phi corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}

fluxRequired
{
default yes;
p;
pcorr;
alpha;
}