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-   -   Problem to run kEpsilonSST in OpenFOAM (http://www.cfd-online.com/Forums/openfoam-solving/118190-problem-run-kepsilonsst-openfoam.html)

 OpenF May 22, 2013 10:58

Problem to run kOmegaSST in OpenFOAM

Hi everyone,

I'm trying to adapt the tutorial "motorBike" which contains kOmegaSST turbulence model to my own case "the Backward facing step".

I'm not running in parallel. I just implemented the classical files to run a computation.

The computation starts and the residuals look good except "time step continuity errors" which crash.

I don't understand where the problem is. My boundaries conditions seem good.

I get this error in the terminal.

Code:

```smoothSolver: Solving for Ux, Initial residual = 0.545989, Final residual = 0.0462827, No Iterations 34 smoothSolver: Solving for Uy, Initial residual = 0.495099, Final residual = 0.0440825, No Iterations 28 GAMG: Solving for p, Initial residual = 0.999999, Final residual = 0.104651, No Iterations 1000 time step continuity errors : sum local = 7.15765e+24, global = -1.17591e+21, cumulative = -1.17591e+21 smoothSolver: Solving for omega, Initial residual = 0.962478, Final residual = 0.0860166, No Iterations 18 smoothSolver: Solving for k, Initial residual = 0.53023, Final residual = 2.24728e-06, No Iterations 1 ExecutionTime = 125.26 s ClockTime = 126 s Time = 34 smoothSolver: Solving for Ux, Initial residual = 0.388555, Final residual = 192672, No Iterations 1000 smoothSolver: Solving for Uy, Initial residual = 0.448615, Final residual = 32484.1, No Iterations 1000 #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #2 in "/lib/x86_64-linux-gnu/libc.so.6" #3 Foam::GAMGSolver::scale(Foam::Field<double>&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #4 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMatrix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #5 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #6 Foam::fvMatrix<double>::solveSegregated(Foam::dictionary const&) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libfiniteVolume.so" #7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/simpleFoam" #8 in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/simpleFoam" #9 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #10 in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/simpleFoam" Floating point exception (core dumped)```
I will be very grateful if someone could help me ! If necessary I can provide other files.

Best regards,
Anselme

 OpenF May 24, 2013 09:49

The computation is still crahing after 34 iterations.. After reading some threads about running in parallel, I think the error come from the turbulence model implementation because originally, the motorbike tutorial is implemented to run in parallel and files "fvSchemes" and "fvSolution" have not been changed. I don't know..

Maybe some files will be usefull to debug the code..

Thank you very much for your assistance !

fvScheme

Code:

``` FoamFile {     version    2.0;     format      ascii;     class      dictionary;     location    "system";     object      fvSchemes; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ddtSchemes {     default        steadyState; } gradSchemes {     default        Gauss linear; } divSchemes {     default        none;     div(phi,U)      bounded Gauss linearUpwindV grad(U);     div(phi,k)      bounded Gauss upwind;     div(phi,omega)  bounded Gauss upwind;     div((nuEff*dev(T(grad(U))))) Gauss linear; } laplacianSchemes {     default        Gauss linear corrected; } interpolationSchemes {     default        linear; } snGradSchemes {     default        corrected; } fluxRequired {     default        no;     p; }```

fvSolution

Code:

```FoamFile {     version    2.0;     format      ascii;     class      dictionary;     location    "system";     object      fvSolution; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // solvers {     p     {         solver          PCG;         preconditioner  DIC;         tolerance        1e-7;         relTol          0.1;     }     U     {         solver          PBiCG;         preconditioner  DILU;         tolerance        1e-8;         relTol          0.1;         nSweeps          1;     }     k     {         solver          PBiCG;         preconditioner  DILU;         tolerance        1e-8;         relTol          0.1;     }     omega     {         solver          PBiCG;         preconditioner  DILU;         tolerance        1e-8;         relTol          0.1;     } } SIMPLE {     nNonOrthogonalCorrectors 0; } potentialFlow {     nNonOrthogonalCorrectors 10; } relaxationFactors {     fields     {         p              0.3;     }     equations     {         U              0.7;         k              0.7;         omega          0.7;     } } cache {     grad(U); }```
ControlDict

Code:

```FoamFile {     version    2.0;     format      ascii;     class      dictionary;     location    "system";     object      controlDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // application    simpleFoam; startFrom      latestTime; startTime      0; stopAt          endTime; endTime        20000; deltaT          1; writeControl    timeStep; writeInterval  200; purgeWrite      0; writeFormat    ascii; writePrecision  6; writeCompression off; timeFormat      general; timePrecision  6; runTimeModifiable true;```
U file

Quote:
 FoamFile { version 2.0; format ascii; class volVectorField; location "0"; object U; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // #include "include/initialConditions" dimensions [0 1 -1 0 0 0 0]; internalField uniform (0 0 0); boundaryField { inlet { type fixedValue; value uniform (10 0 0); } outlet { type zeroGradient; } lowerWall { type fixedValue; value uniform (0 0 0); } upperWall { type fixedValue; value uniform (0 0 0); } frontAndBack { type empty; } }
p file
Code:

```FoamFile {     version    2.0;     format      ascii;     class      volScalarField;     location    "0";     object      p; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // #include        "include/initialConditions" dimensions      [0 2 -2 0 0 0 0]; internalField  uniform \$pressure; boundaryField {     inlet     {         type            zeroGradient;     }     outlet     {         type            fixedValue;         value          \$internalField;     }     lowerWall     {         type            zeroGradient;     }     upperWall     {         type            zeroGradient;     }     frontAndBack     {         type            empty;     } }```
Initialconditions
Code:

```flowVelocity        (10 0 0); pressure            0; turbulentKE          0.24; turbulentOmega      1.78; #inputMode          merge```

 ignacio May 24, 2013 10:41

Regarding your first message. Your turbulent model is kOmega SST, kEpsilon SST does not exist

 OpenF May 24, 2013 10:51

Quote:
 Originally Posted by ignacio (Post 429828) Regarding your first message. Your turbulent model is kOmega SST, kEpsilon SST does not exist
Yes I'm sorry I had slipped on that one..
Thank you, I'll just correct it.

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