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Error during initialization of "rhoSimpleFoam" |
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September 16, 2013, 09:58 |
Error during initialization of "rhoSimpleFoam"
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#1 |
Member
Frank Ubber
Join Date: Aug 2013
Posts: 32
Rep Power: 13 |
Hello everyone,
I am running a "rhoSimpleFoam" case and got an error message while it just initialized the case (see below). At my walls I am using: "alphatWallFunction", "compressible::epsilonWallFunction", "compressible::kqRWallFunction", and "mutkWallFunction". I can't see where I did a mistake, does anybody know what's wrong? Best regards, Frank The error message: Code:
/*---------------------------------------------------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.2.1 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ Build : 2.2.1-57f3c3617a2d Exec : rhoSimpleFoam Date : Sep 16 2013 Time : 14:05:28 Host : "korn-cae-ubuntu" PID : 20302 Case : /home/korn/Arbeitsfläche/case_rotating_compressible nProcs : 1 sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE). fileModificationChecking : Monitoring run-time modified files using timeStampMaster allowSystemOperations : Disallowing user-supplied system call operations // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create mesh for time = 0 SIMPLE: convergence criteria field p tolerance 1e-05 field U tolerance 1e-05 field "(k|epsilon)" tolerance 0.0001 Reading thermophysical properties Selecting thermodynamics package { type hePsiThermo; mixture pureMixture; transport const; thermo hConst; equationOfState perfectGas; specie specie; energy sensibleEnthalpy; } Reading field U Reading/calculating face flux field phi Creating turbulence model Selecting RAS turbulence model kEpsilon #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libOpenFOAM.so" #2 in "/lib/x86_64-linux-gnu/libc.so.6" #3 Foam::compressible::mutkWallFunctionFvPatchScalarField::calcMut() const in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libcompressibleRASModels.so" #4 Foam::compressible::mutWallFunctionFvPatchScalarField::updateCoeffs() in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libcompressibleRASModels.so" #5 Foam::fvPatchField<double>::evaluate(Foam::UPstream::commsTypes) in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/rhoSimpleFoam" #6 Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::GeometricBoundaryField::evaluate() in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/rhoSimpleFoam" #7 Foam::compressible::RASModels::kEpsilon::kEpsilon(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::fluidThermo const&, Foam::word const&, Foam::word const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libcompressibleRASModels.so" #8 Foam::compressible::RASModel::adddictionaryConstructorToTable<Foam::compressible::RASModels::kEpsilon>::New(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::fluidThermo const&, Foam::word const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libcompressibleRASModels.so" #9 Foam::compressible::RASModel::New(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::fluidThermo const&, Foam::word const&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libcompressibleRASModels.so" #10 in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/rhoSimpleFoam" #11 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #12 in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/rhoSimpleFoam" floating-point-exception my "thermophysicalProperties" file: Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 1.6 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; location "constant"; object thermophysicalProperties; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // thermoType { type hePsiThermo; mixture pureMixture; transport const; thermo hConst; equationOfState perfectGas; specie specie; energy sensibleEnthalpy; } pRef 101325; mixture { specie { nMoles 1; molWeight 28.9583; } thermodynamics { Cp 1006.4; Hf 0; } transport { mu 18.205e-06; Pr 0.7081; } } // ************************************************************************* // my "fvSolution" file: Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.1.1 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; object fvSolution; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // solvers { p { solver GAMG; tolerance 1e-7; relTol 0.05; smoother GaussSeidel; nPreSweeps 0; nPostSweeps 2; cacheAgglomeration on; agglomerator faceAreaPair; nCellsInCoarsestLevel 10; mergeLevels 1; } U { solver smoothSolver; smoother GaussSeidel; tolerance 1e-7; relTol 0.1; nSweeps 3; } h { solver PBiCG; preconditioner DILU; tolerance 1e-06; relTol 0.1; } "(k|epsilon)" { solver smoothSolver; smoother GaussSeidel; tolerance 1e-6; relTol 0.1; nSweeps 3; } } SIMPLE { nNonOrthogonalCorrectors 2; rhoMin rhoMin [ 1 -3 0 0 0 ] 0.5; rhoMax rhoMax [ 1 -3 0 0 0 ] 1.5; residualControl { p 1e-5; U 1e-5; "(k|epsilon)" 1e-4; // T 1e-5; } } relaxationFactors { p 0.15; U 0.3; h 0.3; rho 1; k 0.3; epsilon 0.3; } // ************************************************************************* // |
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September 16, 2013, 11:42 |
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#2 |
New Member
Thomas Reviol
Join Date: Jul 2011
Location: Germany, Kaiserslautern
Posts: 27
Rep Power: 15 |
Hello,
you could try to start your simulation without using a turbulence model. When the solver doesn't blow up, you should check the physical plausibility of the initial conditions for the turbulence model. Regards Thomas |
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September 16, 2013, 14:21 |
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#3 |
Member
Frank Ubber
Join Date: Aug 2013
Posts: 32
Rep Power: 13 |
Thanks, Thomas! I did it and it actually ran through without a turbulence model. So it seems something's wrong with my turbulence settings. Do you mean the k and Epsilon initial values with initial conditions for the turbulence model?
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September 16, 2013, 15:31 |
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#4 |
New Member
Thomas Reviol
Join Date: Jul 2011
Location: Germany, Kaiserslautern
Posts: 27
Rep Power: 15 |
Hello,
yes, I meant k and epsilon (or which values your turbulent model is modelling). There is a very usefull tool on cfd-online to estimate k, epsilon, omega and nut. Follow this link. Consider the turbulent length scale! In Fluent it is 7% (I am not Sure about this value) of a length, that is characteristic for your Problem. There is also a hint on the URL above. Since I initialize with the "Fluent-definition", my Simulation is not/rarely blowing up because initial problems. Regards Thomas |
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September 16, 2013, 15:34 |
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#5 |
Member
Frank Ubber
Join Date: Aug 2013
Posts: 32
Rep Power: 13 |
Oh wow, that's neat! Thank you so much! I already calculated k, eps and mut but my values seem to be unrealistic low. I'll try this calculator
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September 16, 2013, 16:01 |
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#6 |
Member
Frank Ubber
Join Date: Aug 2013
Posts: 32
Rep Power: 13 |
Alright I got reasonable values for k&eps but it's still the same error message... I've found THIS site where it's explained where "sigfpe" originates from and it seems that it can only be a "division by 0 from having an initial field set to 0" issue.
I actually do have some initial fields set to 0 (pressure, alphat, mut) but that shouldn't be a problem, right? |
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September 17, 2013, 03:29 |
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#7 |
New Member
Thomas Reviol
Join Date: Jul 2011
Location: Germany, Kaiserslautern
Posts: 27
Rep Power: 15 |
Hmm ..ok, there seems to be another mistake. I often set pressure to zero. Did you run checkMesh? Maybe there are bad elements?
You can also unset the Floating Point Exception control by using this command "unset FOAM_SIGFPE". Sometimes, the calculation became stable after a few Iteration steps. |
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September 17, 2013, 06:08 |
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#8 | |
Member
Frank Ubber
Join Date: Aug 2013
Posts: 32
Rep Power: 13 |
Yes, I did checkMesh and there are actually some high aspect ratio cells. But I did some incompressible simpleFoam calculations before with this mesh and I never had with those before. I also changed the inlet- and outlet types of k/eps but the error message remains the same.
It's interesting that the message occurs even before the first iteration started, does the solver even check the plausibility of the bc valued in this state? If I unset sigFpe it actually runs through to the first iteration. The Ux/Uy/Uz residuals are pretty reasonable but my h-initial-residual is already at 10^-6 at the first iteration. And every following one (T, k, eps) are "nan". In a different post I found this if the "nan" error occurs: Quote:
In the T-file I just defined a fixedValue at the inlet and a inletOutlet at the outlet. In the pressure-file I defined a totalPressure inlet and a fixedValue outlet. And in the U-file I defined a pressureInletVelocity inlet and a zeroGradient outlet. The simulation with the U- and p-bcs worked fine with simpleFoam. my k-file: Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.1.1 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object k; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -2 0 0 0 0]; internalField uniform 3.6; boundaryField { //FAN fan_hub { type compressible::kqRWallFunction; value $internalField; } fan_wall { type compressible::kqRWallFunction; value $internalField; } fan_cyclic_right { type cyclic; } fan_cyclic_left { type cyclic; } fan_blade_front { type compressible::kqRWallFunction; value $internalField; } fan_blade_back { type compressible::kqRWallFunction; value $internalField; } fan_blade_wall { type compressible::kqRWallFunction; value $internalField; } //INLET inlet { type turbulentIntensityKineticEnergyInlet; //was fixedvalue intensity 0.05; value uniform 3.6; } inlet_cyclic_right { type cyclic; } inlet_cyclic_left { type cyclic; } inlet_wall { type compressible::kqRWallFunction; value $internalField; } inlet_hub_fan { type compressible::kqRWallFunction; value $internalField; } inlet_front_wall { type compressible::kqRWallFunction; value $internalField; } //OUTLET outlet { type inletOutlet; inletValue uniform 3.6; value uniform 3.6; } outlet_cyclic_right { type cyclic; } outlet_cyclic_left { type cyclic; } outlet_hub { type compressible::kqRWallFunction; value $internalField; } outlet_fan_hub { type compressible::kqRWallFunction; value $internalField; } outlet_back_wall { type compressible::kqRWallFunction; value $internalField; } outlet_case_wall { type compressible::kqRWallFunction; value $internalField; } outlet_wall { type compressible::kqRWallFunction; value $internalField; } } // ************************************************************************* // my eps-file: Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.1.1 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object epsilon; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -3 0 0 0 0]; internalField uniform 27; boundaryField { //FAN fan_hub { type compressible::epsilonWallFunction; value $internalField; } fan_wall { type compressible::epsilonWallFunction; value $internalField; } fan_cyclic_right { type cyclic; } fan_cyclic_left { type cyclic; } fan_blade_front { type compressible::epsilonWallFunction; value $internalField; } fan_blade_back { type compressible::epsilonWallFunction; value $internalField; } fan_blade_wall { type compressible::epsilonWallFunction; value $internalField; } //INLET inlet { type compressible::turbulentMixingLengthDissipationRateInlet; mixingLength 0.005; value uniform 27; } inlet_cyclic_right { type cyclic; } inlet_cyclic_left { type cyclic; } inlet_wall { type compressible::epsilonWallFunction; value $internalField; } inlet_hub_fan { type compressible::epsilonWallFunction; value $internalField; } inlet_front_wall { type compressible::epsilonWallFunction; value $internalField; } //OUTLET outlet { type inletOutlet; inletValue uniform 27; value uniform 27; } outlet_cyclic_right { type cyclic; } outlet_cyclic_left { type cyclic; } outlet_hub { type compressible::epsilonWallFunction; value $internalField; } outlet_fan_hub { type compressible::epsilonWallFunction; value $internalField; } outlet_back_wall { type compressible::epsilonWallFunction; value $internalField; } outlet_case_wall { type compressible::epsilonWallFunction; value $internalField; } outlet_wall { type compressible::epsilonWallFunction; value $internalField; } } // ************************************************************************* // my mut-file: Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 1.6 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object mut; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [1 -1 -1 0 0 0 0]; internalField uniform 0; boundaryField { //FAN fan_hub { type mutkWallFunction; value uniform 0; } fan_wall { type mutkWallFunction; value uniform 0; } fan_cyclic_right { type cyclic; } fan_cyclic_left { type cyclic; } fan_blade_front { type mutkWallFunction; value uniform 0; } fan_blade_back { type mutkWallFunction; value uniform 0; } fan_blade_wall { type mutkWallFunction; value uniform 0; } //INLET inlet { type calculated; value uniform 0; } inlet_cyclic_right { type cyclic; } inlet_cyclic_left { type cyclic; } inlet_wall { type mutkWallFunction; value uniform 0; } inlet_hub_fan { type mutkWallFunction; value uniform 0; } inlet_front_wall { type mutkWallFunction; value uniform 0; } //OUTLET outlet { type calculated; value uniform 0; } outlet_cyclic_right { type cyclic; } outlet_cyclic_left { type cyclic; } outlet_hub { type mutkWallFunction; value uniform 0; } outlet_fan_hub { type mutkWallFunction; value uniform 0; } outlet_back_wall { type mutkWallFunction; value uniform 0; } outlet_case_wall { type mutkWallFunction; value uniform 0; } outlet_wall { type mutkWallFunction; value uniform 0; } } // ************************************************************************* // my alphat-file: Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 1.6 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object alphat; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [1 -1 -1 0 0 0 0]; internalField uniform 0.0001; boundaryField { //FAN fan_hub { type alphatWallFunction; value $internalField; } fan_wall { type alphatWallFunction; value $internalField; } fan_cyclic_right { type cyclic; } fan_cyclic_left { type cyclic; } fan_blade_front { type alphatWallFunction; value $internalField; } fan_blade_back { type alphatWallFunction; value $internalField; } fan_blade_wall { type alphatWallFunction; value $internalField; } //INLET inlet { type calculated; value $internalField; } inlet_cyclic_right { type cyclic; } inlet_cyclic_left { type cyclic; } inlet_wall { type alphatWallFunction; value $internalField; } inlet_hub_fan { type alphatWallFunction; value $internalField; } inlet_front_wall { type alphatWallFunction; value $internalField; } //OUTLET outlet { type calculated; value $internalField; } outlet_cyclic_right { type cyclic; } outlet_cyclic_left { type cyclic; } outlet_hub { type alphatWallFunction; value $internalField; } outlet_fan_hub { type alphatWallFunction; value $internalField; } outlet_back_wall { type alphatWallFunction; value $internalField; } outlet_case_wall { type alphatWallFunction; value $internalField; } outlet_wall { type alphatWallFunction; value $internalField; } } // ************************************************************************* // |
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September 17, 2013, 06:37 |
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#9 |
New Member
Thomas Reviol
Join Date: Jul 2011
Location: Germany, Kaiserslautern
Posts: 27
Rep Power: 15 |
On a first view, I didn't see a mistake in your conditions (although the values for k and epsilon seems to be realy high). Could you send me a PM with a zip-file from your case? Then I will try to find out whats wrong.
Thomas |
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