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-   -   how to use 'turbFoam standard k-Epsilon ?' (https://www.cfd-online.com/Forums/openfoam/69416-how-use-turbfoam-standard-k-epsilon.html)

 panda60 October 22, 2009 06:27

how to use 'turbFoam standard k-Epsilon ?'

Dear Foamers:
I want to simulate the air flow across an single building . I try to use the standard k-Epsilon of turbFoam. This is my steps:
1. generate the mesh using ICEM in windows, and then save to *.msh;
2. using "fluentMeshToFoam *.msh -scale 0.001",convert to foam mesh;
3.checkMesh, no problem;
4.copy turorials/turbFoam/cavity to my case directory, delete the "nuTilda and R" files, note the nuTilda and R lines in fvSchemes file.

divSchemes
{
default none;
div(phi,U) Gauss limitedLinearV 1;
div(phi,k) Gauss limitedLinear 1;
div(phi,epsilon) Gauss limitedLinear 1;
// div(phi,R) Gauss limitedLinear 1;
// div(R) Gauss linear;
// div(phi,nuTilda) Gauss limitedLinear 1;
div((nuEff*dev(grad(U).T()))) Gauss linear;
}
laplacianSchemes
{
default none;
laplacian(nuEff,U) Gauss linear corrected;
laplacian((1|A(U)),p) Gauss linear corrected;
laplacian(DkEff,k) Gauss linear corrected;
laplacian(DepsilonEff,epsilon) Gauss linear corrected;
// laplacian(DREff,R) Gauss linear corrected;
// laplacian(DnuTildaEff,nuTilda) Gauss linear corrected;
}

5. when I run , it displays the following mistakes:
kEpsilonCoeffs
{
Cmu 0.09;
C1 1.44;
C2 1.92;
alphaEps 0.76923;
}

Starting time loop
Time = 0.0005
Courant Number mean: 0.0197359 max: 0.237347
DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 1.2995e-06, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 1.91917e-09, No Iterations 2
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 7.8287e-09, No Iterations 2
DICPCG: Solving for p, Initial residual = 1, Final residual = 9.7326e-07, No Iterations 177
time step continuity errors : sum local = 1.35378e-10, global = 9.41494e-13, cumulative = 9.41494e-13
DICPCG: Solving for p, Initial residual = 0.0826107, Final residual = 9.50741e-07, No Iterations 158
time step continuity errors : sum local = 4.28276e-11, global = 1.23514e-13, cumulative = 1.06501e-12
DILUPBiCG: Solving for epsilon, Initial residual = 0.556573, Final residual = 1.13615e-06, No Iterations 2
DILUPBiCG: Solving for k, Initial residual = 1, Final residual = 2.70281e-07, No Iterations 3
ExecutionTime = 10.26 s ClockTime = 11 s

It seems does not converge. because I'm newer , don't understand why. If it is because I haven't used turbFoam k-Epsilon correctly?
I think it is only an simple case ,fluent can solve this easily, Why OpenFOAM has so many problem?
Thank you very much.

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