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January 17, 2015, 10:42 |
simpleFoam: floating point exception
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#1 |
Senior Member
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Hi all,
i'm facing a floating point exception as for bounding of k on a MRF simulation with simpleFoam. As you may see, k bounding min value goes zero and then solution blows up. Code:
/*---------------------------------------------------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.1 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ Build : 2.3.1-bcfaaa7b8660 Exec : simpleFoam Date : Jan 17 2015 Time : 14:00:39 Host : "imatUbuntu" PID : 10043 Case : /home/imatubuntu/OpenFOAM/imatubuntu-2.3.1/run/work/daria_small/canaleOutEBM/run nProcs : 1 sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE). fileModificationChecking : Monitoring run-time modified files using timeStampMaster allowSystemOperations : Allowing user-supplied system call operations // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create mesh for time = 450 Reading field p Reading field U Reading/calculating face flux field phi AMI: Creating addressing and weights between 23802 source faces and 24851 target faces AMI: Patch source sum(weights) min/max/average = 0.99887638, 1.0072276, 1.0003408 AMI: Patch target sum(weights) min/max/average = 0.99894094, 1.0013817, 1.0000049 AMI: Creating addressing and weights between 19122 source faces and 4952 target faces AMI: Patch source sum(weights) min/max/average = 0.81524507, 1.0000002, 0.99936938 AMI: Patch target sum(weights) min/max/average = 0.88260207, 1, 0.99875295 AMI: Creating addressing and weights between 12730 source faces and 2812 target faces AMI: Patch source sum(weights) min/max/average = 0.99845796, 1.0051665, 1.0002107 AMI: Patch target sum(weights) min/max/average = 0.99968809, 1.0016961, 1.0000635 Selecting incompressible transport model Newtonian Selecting RAS turbulence model kEpsilon bounding k, min: 3.4598366e-31 max: 790.70186 average: 1.6601081 kEpsilonCoeffs { Cmu 0.09; C1 1.44; C2 1.92; sigmaEps 1.3; } Creating finite volume options from "system/fvOptions" Selecting finite volume options model type MRFSource Source: MRF1 - applying source for all time - selecting cells using cellZone MRF - selected 2071456 cell(s) with volume 0.00052479319 Selecting finite volume options model type explicitPorositySource Source: porosity1 - applying source for all time - selecting cells using cellZone batteria - selected 316332 cell(s) with volume 0.0017791776 Porosity region porosity1: selecting model: DarcyForchheimer creating porous zone: batteria SIMPLE: convergence criteria field p tolerance 0.0001 field U tolerance 0.001 field "(k|epsilon|omega)" tolerance 0.001 Starting time loop phi: phi Compressible: 0 Turbulent: 1 LES: 0 Time = 465 --> FOAM Warning : From function gaussConvectionScheme in file finiteVolume/convectionSchemes/gaussConvectionScheme/gaussConvectionScheme.H at line 123 Reading "/home/imatubuntu/OpenFOAM/imatubuntu-2.3.1/run/work/daria_small/canaleOutEBM/run/system/fvSchemes.divSchemes.div(phi,U)" at line 34 Unbounded 'Gauss' div scheme used in steady-state solver, use 'bounded Gauss' to ensure boundedness. To remove this warning switch off 'warnUnboundedGauss' in "/opt/openfoam231/etc/controlDict" DILUPBiCG: Solving for Ux, Initial residual = 0.00073404819, Final residual = 1.4551955e-05, No Iterations 1 DILUPBiCG: Solving for Uy, Initial residual = 0.00060673146, Final residual = 1.1398202e-05, No Iterations 1 DILUPBiCG: Solving for Uz, Initial residual = 0.00067247603, Final residual = 1.2637159e-05, No Iterations 1 GAMG: Solving for p, Initial residual = 0.00093841547, Final residual = 8.1897134e-07, No Iterations 7 GAMG: Solving for p, Initial residual = 6.7902153e-05, Final residual = 6.4216769e-08, No Iterations 8 time step continuity errors : sum local = 1.9119291e-06, global = 5.0391913e-07, cumulative = 2.4629033e-06 DILUPBiCG: Solving for epsilon, Initial residual = 0.00011465046, Final residual = 3.22368e-06, No Iterations 1 DILUPBiCG: Solving for k, Initial residual = 0.00019167693, Final residual = 3.4461782e-06, No Iterations 1 bounding k, min: 0 max: 789.99843 average: 1.6552599 ExecutionTime = 602.8 s ClockTime = 604 s MassFlows: outlet = 37.136307 inlet = -37.127109 Time = 466 --> FOAM Warning : From function gaussConvectionScheme in file finiteVolume/convectionSchemes/gaussConvectionScheme/gaussConvectionScheme.H at line 123 Reading "/home/imatubuntu/OpenFOAM/imatubuntu-2.3.1/run/work/daria_small/canaleOutEBM/run/system/fvSchemes.divSchemes.div(phi,U)" at line 34 Unbounded 'Gauss' div scheme used in steady-state solver, use 'bounded Gauss' to ensure boundedness. To remove this warning switch off 'warnUnboundedGauss' in "/opt/openfoam231/etc/controlDict" DILUPBiCG: Solving for Ux, Initial residual = 0.00073368581, Final residual = 1.4702976e-05, No Iterations 1 DILUPBiCG: Solving for Uy, Initial residual = 0.00060705033, Final residual = 1.1472962e-05, No Iterations 1 DILUPBiCG: Solving for Uz, Initial residual = 0.00067250209, Final residual = 1.2664494e-05, No Iterations 1 GAMG: Solving for p, Initial residual = 0.00093413777, Final residual = 5.7548539e-07, No Iterations 7 GAMG: Solving for p, Initial residual = 6.7233025e-05, Final residual = 4.1306896e-08, No Iterations 9 time step continuity errors : sum local = 1.2317376e-06, global = -8.7246108e-08, cumulative = 2.3756572e-06 #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 in "/lib/x86_64-linux-gnu/libc.so.6" #3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) at ??:? #4 void Foam::divide<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:? #5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator/<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) at ??:? #6 Foam::incompressible::RASModels::kEpsilon::correct() at ??:? #7 at ??:? #8 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #9 at ??:? Floating point exception (core dumped) Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.2.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; location "system"; object fvSchemes; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ddtSchemes { default steadyState; } gradSchemes { default cellLimited Gauss linear 1; //Gauss linear// /* grad(p) cellLimited Gauss linear 1;// Gauss; grad(U) Gauss;*/ } divSchemes { default none; // div(phi,U) bounded Gauss linearUpwind default; //Joel suggestion div(phi,U) Gauss linearUpwindV cellLimited Gauss linear 1; //Alberto http://www.cfd-online.com/Forums/openfoam/74618-simplefoam-convergence-large-domain-2.html //div(phi,U) bounded Gauss limitedLinear 1; // bounded Gauss upwind div(phi,k) bounded Gauss upwind; div(phi,epsilon) bounded Gauss upwind; div((nuEff*dev(T(grad(U))))) Gauss linear; } laplacianSchemes { default Gauss linear limited 0.5; //Joel suggestion // default Gauss linear limited 0.333;;//Gauss linear corrected; /* 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; */} interpolationSchemes { default linear; // interpolate(U) linear; } snGradSchemes { //default limited 0.5; //joel suggestion // default limited 0; default corrected; } fluxRequired { default no; p ; } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.2.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; location "system"; object fvSolution; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // solvers { p { solver GAMG; tolerance 1e-08; relTol 0.001;//era 0.05 smoother GaussSeidel; cacheAgglomeration true; nCellsInCoarsestLevel 20; agglomerator faceAreaPair; mergeLevels 1; } U { solver PBiCG; preconditioner DILU; tolerance 1e-05; relTol 0.1; } k { solver PBiCG; preconditioner DILU; tolerance 1e-05; relTol 0.1; } epsilon { solver PBiCG; preconditioner DILU; tolerance 1e-05; relTol 0.1; } } potentialFlow { nNonOrthogonalCorrectors 1; //era10 } SIMPLE { nNonOrthogonalCorrectors 1; residualControl { p 1e-4; U 1e-3; "(k|epsilon|omega)" 1e-3; } } relaxationFactors { fields { p 0.2;//0.2; } equations { U 0.3;//0.3;; k 0.3;//0.3;; epsilon 0.3;//0.3;; } } // ************************************************************************* // thanks a lot |
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January 17, 2015, 11:41 |
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#2 |
Senior Member
anonymous
Join Date: Aug 2014
Posts: 205
Rep Power: 13 |
bounding k, min: 0 max: 789.99843 average: 1.6552599
The max value doesn't seem to be right, which are your boundary conditions for the turbulence variables? What does checkMesh say about your mesh? |
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January 17, 2015, 12:57 |
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#3 | |
Senior Member
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Hi,
thanks for answering. Just for understanding why do you say? Quote:
Code:
/*---------------------------------------------------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.1 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ Build : 2.3.1-bcfaaa7b8660 Exec : checkMesh -parallel Date : Jan 17 2015 Time : 17:43:48 Host : "imatUbuntu" PID : 8809 Case : /home/imatubuntu/OpenFOAM/imatubuntu-2.3.1/run/work/daria_small/canaleOutEBM/run nProcs : 8 Slaves : 7 ( "imatUbuntu.8810" "imatUbuntu.8811" "imatUbuntu.8812" "imatUbuntu.8813" "imatUbuntu.8814" "imatUbuntu.8815" "imatUbuntu.8816" ) Pstream initialized with: floatTransfer : 0 nProcsSimpleSum : 0 commsType : nonBlocking polling iterations : 0 sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE). fileModificationChecking : Monitoring run-time modified files using timeStampMaster allowSystemOperations : Allowing user-supplied system call operations // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Create polyMesh for time = 0 Time = 0 Mesh stats points: 4172243 faces: 11183065 internal faces: 10306710 cells: 3505516 faces per cell: 6.1302744 boundary patches: 21 point zones: 0 face zones: 0 cell zones: 3 Overall number of cells of each type: hexahedra: 3271330 prisms: 22206 wedges: 0 pyramids: 24665 tet wedges: 0 tetrahedra: 13498 polyhedra: 173817 Breakdown of polyhedra by number of faces: faces number of cells 6 27315 7 11608 8 1449 9 102527 12 24206 13 2 15 6082 16 1 17 1 18 372 20 4 21 190 24 60 Checking topology... Boundary definition OK. Cell to face addressing OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. *Number of regions: 3 The mesh has multiple regions which are not connected by any face. <<Writing region information to "0/cellToRegion" <<Writing region 0 with 2064714 cells to cellSet region0 <<Writing region 1 with 726918 cells to cellSet region1 <<Writing region 2 with 713884 cells to cellSet region2 Checking basic patch addressing... Patch Faces Points AMI_ROT1 23802 25146 AMI_ROT3 19122 19718 AMI_ROT2 12730 13839 blades 299506 302735 boccaglio 125559 127400 wallStat 31222 32677 amiAsp1 2812 3124 amiAsp2 4952 5017 inlet 16413 16848 tubi 38109 38461 wallAsp 41432 41375 wallBatt 32061 33455 wallDead 3590 3824 amiFanRotating 24851 25628 outlet 74704 74937 wallEspulsione 56594 57131 wallExt 13638 14000 Checking geometry... Overall domain bounding box (-0.173186 -0.2175 -0.35) (0.54 0.8 0.32225) Mesh (non-empty, non-wedge) directions (1 1 1) Mesh (non-empty) directions (1 1 1) Boundary openness (-1.1273693e-15 -6.0712876e-15 -5.5882177e-16) OK. Max cell openness = 3.9932212e-16 OK. Max aspect ratio = 22.763918 OK. Minimum face area = 1.1992557e-13. Maximum face area = 0.00023338634. Face area magnitudes OK. Min volume = 2.829272e-14. Max volume = 3.7684994e-06. Total volume = 0.12891844. Cell volumes OK. Mesh non-orthogonality Max: 79.296812 average: 6.0672307 *Number of severely non-orthogonal (> 70 degrees) faces: 103. Non-orthogonality check OK. <<Writing 103 non-orthogonal faces to set nonOrthoFaces Face pyramids OK. ***Max skewness = 5.0571991, 82 highly skew faces detected which may impair the quality of the results <<Writing 99 skew faces to set skewFaces Coupled point location match (average 0) OK. Failed 1 mesh checks. End Finalising parallel run Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.0 | | \\ / 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 0.03375; boundaryField { outlet { type zeroGradient; } inlet { type zeroGradient; } wallAsp { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } wallDead { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } wallExt { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } boccaglio { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } blades { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } wallStat { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } /* wallFan { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; }*/ wallEspulsione { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } tubi { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } wallBatt { type kLowReWallFunction; //kqRWallFunction; value uniform 0.0000001; } AMI_ROT1 { type cyclicAMI; value $internalField; } AMI_ROT2 { type cyclicAMI; value $internalField; } AMI_ROT3 { type cyclicAMI; value $internalField; } amiAsp1 { type cyclicAMI; value $internalField; } amiAsp2 { type cyclicAMI; value $internalField; } amiFanRotating { type cyclicAMI; value $internalField; } } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.0.1 | | \\ / A nd | Web: www.OpenFOAM.com | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object epsilon; // EPSILON = Turbulent Dissipation Rate recalculate // for each new case. e=Cu*((k^(3/2))/l) // Cu=Turbulent Constant=0.09 // k=Turbulent Kinetic Energy l=Turbulent Length Scale // l can be estimated. l=0.038*dh dh=pipe diameter } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -3 0 0 0 0]; internalField uniform 0.006975; // was 0.000765 boundaryField { outlet { type zeroGradient; } inlet { type zeroGradient; } wallAsp { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } wallDead { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } wallExt { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } boccaglio { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } blades { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } wallStat { value uniform 0.006975; } wallEspulsione { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } tubi { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } wallBatt { type epsilonLowReWallFunction; //epsilonWallFunction; value uniform 0.006975; } AMI_ROT1 { type cyclicAMI; value $internalField; } AMI_ROT2 { type cyclicAMI; value $internalField; } AMI_ROT3 { type cyclicAMI; value $internalField; } amiAsp1 { type cyclicAMI; value $internalField; } amiAsp2 { type cyclicAMI; value $internalField; } amiFanRotating { type cyclicAMI; value $internalField; } } // ************************************************************************* // Code:
Time = 100 Reading field U Reading/calculating face flux field phi Selecting incompressible transport model Newtonian Selecting RAS turbulence model kEpsilon kEpsilonCoeffs { Cmu 0.09; C1 1.44; C2 1.92; sigmaEps 1.3; } Patch 3 named blades y+ : min: 0.67807798 max: 47.861605 average: 10.385627 Patch 4 named boccaglio y+ : min: 0.15849079 max: 42.118054 average: 3.7682556 Patch 5 named wallStat y+ : min: 0.36632298 max: 10.071332 average: 4.5537257 Patch 9 named tubi y+ : min: 0.10642169 max: 23.319607 average: 3.006639 Patch 10 named wallAsp y+ : min: 0.00080009906 max: 8.0571449 average: 1.8477912 Patch 11 named wallBatt y+ : min: 0.026648156 max: 30.8113 average: 2.1785036 Patch 12 named wallDead y+ : min: 0.00056670836 max: 2.7034135 average: 0.53314965 Patch 15 named wallEspulsione y+ : min: 0.15375772 max: 13.502387 average: 3.3477829 Patch 16 named wallExt y+ : min: 0.039157284 max: 3.4930396 average: 0.58972471 Writing yPlus to field yPlus End |
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January 17, 2015, 15:51 |
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#4 | ||
Retired Super Moderator
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
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Greetings to all!
Quote:
From what I can see from the boundary conditions you've described, it seems to me that you've incorrectly defined them. I say this because you posted that you have the following boundary condition in the file "epsilon": Code:
wallStat { value uniform 0.006975; } Therefore, my guess is that you've modified the field files in the "0" folder, after having already simulated for 465 iterations or less. Which is why you should double-check the boundary conditions you have defined for these field files in the folder "465". Best regards, Bruno |
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January 17, 2015, 17:58 |
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#5 |
Senior Member
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Hi and thanks.
I think the best solution is re-mesh the whole domain once again. Maybe skewness is quite surely 20% of the problem that can help me to improve by 80%. By the way I try to ask: what's the reason of using bounding schemes? or where can I read something about them? About turbulence BC: as for complex geometry it's quite hard to keep a proper value for y+; are epsilonLowReWallFunction & kLowReWallFunction a good alternative choice for wall functions? Bye |
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January 18, 2015, 05:16 |
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#6 | |
Retired Super Moderator
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
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Quick answers:
Quote:
Personally I've only recently found about the existence of these wall functions. I have not yet managed to fully understand in what situations it's correct to use them, therefore my advice is that you first test with simpler cases and prove with those cases if those boundary conditions are good enough for your case or not. |
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February 12, 2016, 05:56 |
MRFSimpleFoam - Convergence Problem!!
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#7 |
New Member
ravi
Join Date: Nov 2013
Posts: 10
Rep Power: 13 |
Hi all,
I am trying to simulate a centrifugal fan with 3 individual meshes merged-(suction, impeller and spiral). My BC's are : Total Pressure Inlet and Volumetric Flow Outlet. My solver is blowing up showing the time step errors, bounding k and bounding epsilon in the range of e+30. How should I rectify this problem? CheckMesh result is: ------------------------------------------------------------------------------- Time = 0 Mesh stats points: 814585 faces: 8243673 internal faces: 7706091 cells: 3987441 faces per cell: 4 boundary patches: 18 point zones: 0 face zones: 3 cell zones: 3 Overall number of cells of each type: hexahedra: 0 prisms: 0 wedges: 0 pyramids: 0 tet wedges: 0 tetrahedra: 3987441 polyhedra: 0 Checking topology... Boundary definition OK. Cell to face addressing OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. Topological cell zip-up check OK. Face-face connectivity OK. <<Writing 7128 cells with two non-boundary faces to set twoInternalFacesCells *Number of regions: 3 The mesh has multiple regions which are not connected by any face. <<Writing region information to "0/cellToRegion" <<Writing region 0 with 1619250 cells to cellSet region0 <<Writing region 1 with 1005986 cells to cellSet region1 <<Writing region 2 with 1362205 cells to cellSet region2 Checking patch topology for multiply connected surfaces... Patch Faces Points Surface topology Bounding box BOTTOM_SUCTION 5851 3445 ok (non-closed singly connected) (-3.22441 -0.712981 0.619) (0.712984 3.22441 0.619) ...... CP_1_SPIRAL 2407 2391 ok (non-closed singly connected) (-0.807087 -0.806972 0.415827) (0.807087 0.806995 0.494288) Checking geometry... Overall domain bounding box (-3.22441 -3.022 -0.132) (1.8 3.22441 1.564) Mesh (non-empty, non-wedge) directions (1 1 1) Mesh (non-empty) directions (1 1 1) Boundary openness (2.36031e-16 2.32438e-17 -1.14065e-15) OK. Max cell openness = 3.07852e-16 OK. Max aspect ratio = 6.08759 OK. Minimum face area = 3.71673e-07. Maximum face area = 0.00797706. Face area magnitudes OK. Min volume = 1.86704e-10. Max volume = 0.00016558. Total volume = 19.3189. Cell volumes OK. Mesh non-orthogonality Max: 68.1213 average: 15.5462 Non-orthogonality check OK. Face pyramids OK. Max skewness = 0.749613 OK. Coupled point location match (average 0) OK. Face tets OK. Min/max edge length = 0.000457433 0.15509 OK. <<Writing 16 near (closer than 8.19382e-06 apart) points to set nearPoints All angles in faces OK. All face flatness OK. Cell determinant (wellposedness) : minimum: 0 average: 1.47314 ***Cells with small determinant (< 0.001) found, number of cells: 7128 <<Writing 7128 under-determined cells to set underdeterminedCells Concave cell check OK. Face interpolation weight : minimum: 0.0775184 average: 0.437831 Face interpolation weight check OK. Face volume ratio : minimum: 0.0840324 average: 0.794736 Face volume ratio check OK. Failed 1 mesh checks. End ---------------------------------------------------------------------------- Please check the file attached and guide me. I have removed the polyMesh file as it is confidential. https://drive.google.com/file/d/0B7c...ew?usp=sharing |
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February 21, 2016, 15:20 |
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#8 | |
Retired Super Moderator
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,981
Blog Entries: 45
Rep Power: 128 |
Quote:
If you can provide a complete test case that reproduces the same error, but while using a non-confidential geometry/mesh, then anyone will be able to assist you. It's very simple, you only have to use a very simple format/shape for the blades and any other pieces, while at the same time you use the same case set-up strategy.
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February 23, 2016, 08:36 |
Ercoftac Centrifugal Pump - 3D - Convergence Issue
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#9 |
New Member
ravi
Join Date: Nov 2013
Posts: 10
Rep Power: 13 |
I am facing convergence problem while running Ercoftac Centrifugal Pump (3D case) using MRF approach in OF 2.4, OS: Ubuntu 14.04. I am getting some bounding epsilon and k problems. Pls let me know the corrections/suggestions. You can find the case here:
https://drive.google.com/file/d/0B7c...ew?usp=sharing |
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March 13, 2016, 19:23 |
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#10 |
Retired Super Moderator
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 10,981
Blog Entries: 45
Rep Power: 128 |
Quick answer: I've taken a look into your case and there are 2 apparent critical issues:
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