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Problem in fvschemes divSchemes cannot use Gauss linearUpwind |
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November 16, 2011, 04:02 |
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#21 |
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Felipe
Join Date: Apr 2010
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how do your results compare to measurements? are you under or over predicting?
In my case I over predict from 10 to 20 degrees |
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August 2, 2012, 15:34 |
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#22 |
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Join Date: Jun 2012
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hi all
I noticed that both in both tutorial cases and posted fvschemes there is always Code:
div(R) Gauss linear; I tried Code:
div(R) Gauss limitedLinear 1; div(R) Gauss QUICK; div(R) Gauss MUSCL; thanks Uli |
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August 2, 2012, 15:40 |
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#23 |
Senior Member
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Hi! It is for other turbulence model where you use Reynolds stress
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Best regards, Dr. Alexander VAKHRUSHEV Christian Doppler Laboratory for "Metallurgical Applications of Magnetohydrodynamics" Simulation and Modelling of Metallurgical Processes Department of Metallurgy University of Leoben http://smmp.unileoben.ac.at |
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August 2, 2012, 16:12 |
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#24 |
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Thanks for your reply.
So using a k-Epsilon model does not involve R? But how is it possible that I get different results after switching the scheme for div(R)? |
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August 2, 2012, 16:18 |
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#25 |
Senior Member
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You wrote you get the SAME results. You can easily check which schemes you solver uses, just set "default none;", and you will get errors until you define all schemes.
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Best regards, Dr. Alexander VAKHRUSHEV Christian Doppler Laboratory for "Metallurgical Applications of Magnetohydrodynamics" Simulation and Modelling of Metallurgical Processes Department of Metallurgy University of Leoben http://smmp.unileoben.ac.at |
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August 21, 2012, 19:34 |
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#26 |
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hi, sorry for the late reply.
I wrote "similar" results since the plots are slightly different. I removed the schemes and it still worked, thanks for your help. |
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April 9, 2014, 02:54 |
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#27 |
Member
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Hi all,
I have to simulate the case of time varying BC 'uniformValue' for p and T I tried various ways listed here and also from other open-sources, for schemes and solvers, to solve the 'p' with rhoSimpleFoam. whatever may be the conditions applied, the solver is unable to run after third time-step. here I am posting my schemes and solvers. I am thinking that the problem is with these files only because I have cross-checked the p, T and U files and am also able to run 'rhoPimpleFoam' successfully. Please let me know what went wrong. Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.2.2 | | \\ / 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 leastSquares 1;//Gauss linear; // grad(U) Gauss linear; grad(P) Gauss linear; } divSchemes { default none;//Gauss linear corrected; // div(phi,U) bounded Gauss upwind; div((muEff*dev2(T(grad(U))))) Gauss linear; div(phi,e) bounded Gauss upwind; div(phi,h) bounded Gauss upwind; div(phi,epsilon) bounded Gauss upwind; div(phi,omega) bounded Gauss upwind; div(phi,k) bounded Gauss upwind; div(phi,K) bounded Gauss upwind; div(phi,Ekp) bounded Gauss upwind; div(phid,p) Gauss upwind;//bounded Gauss upwind; div(U,p) bounded Gauss upwind; } laplacianSchemes { default Gauss linear orthogonal;//Gauss linear corrected; // laplacian(muEff,U) Gauss linear corrected; // laplacian(alphaEff,e) Gauss linear corrected; // laplacian(alphaEff,h) Gauss linear corrected; // laplacian((rho*(1|A(U))),p) Gauss linear corrected; // laplacian((rho|A(U)),p) Gauss linear corrected; // laplacian((rho*rAU),p) Gauss linear corrected; // laplacian(DepsilonEff,epsilon) Gauss linear corrected; // laplacian(DomegaEff,omega) Gauss linear corrected; // laplacian(DkEff,k) Gauss linear corrected; // laplacian(1,p) Gauss linear corrected; } interpolationSchemes { default linear; div(U,p) upwind phi; } snGradSchemes { default corrected; } fluxRequired { default no; p ; } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.2.2 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; location "system"; object fvSolution; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // solvers { p { solver PCG;//GAMG;// preconditioner none;//DIC;//FDIC;//GAMG;//diagonal;// agglomerator faceAreaPair; tolerance 1e-07; relTol 0;//0.05; smoother GaussSeidel; cacheAgglomeration true;//off; nCellsInCoarsestLevel 10;//20; mergeLevels 1; } //temperoraily not using "(U|e|h|R|k|epsilon|omega)" //"(U|p|e|h|R|k|epsilon|omega)" { solver smoothSolver;//solver diagonal;// smoother GaussSeidel; nSweeps 2; tolerance 1e-06; // relTol 0; //0.1; // solver PBiCG; // preconditioner DILU; // tolerance 1e-06; // relTol 0; //0.1; } // "(k|epsilon|omega)" // { // $U; // tolerance 1e-05; // relTol 0; //0.1; // } } SIMPLE { nNonOrthogonalCorrectors 0; rhoMin rhoMin [ 1 -3 0 0 0 ] 0.4; rhoMax rhoMax [ 1 -3 0 0 0 ] 1.5; residualControl { p 1e-2; U 1e-4; e 1e-3; // possibly check turbulence fields "(k|epsilon|omega)" 1e-3; } // residual control temporarily not used } PIMPLE { momentumPredictor yes; nOuterCorrectors 1; nCorrectors 1; nNonOrthogonalCorrectors 0; rhoMin rhoMin [ 1 -3 0 0 0 ] 0.5; rhoMax rhoMax [ 1 -3 0 0 0 ] 2.0; maxCo 0.2; rDeltaTSmoothingCoeff 0.1; rDeltaTDampingCoeff 1; maxDeltaT 1; } relaxationFactors { fields { p 0.03; rho 0.05; } equations { U 0.07; "(k|epsilon|omega)" 0.04; e 0.05; h 0.01; } } // ************************************************************************* // |
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June 3, 2014, 06:29 |
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#28 | |
Senior Member
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Quote:
A user can edit those files. Use the following conditions for relaxation factors: relaxationFactors { fields { p 0.3; rho 1; } equations { U 0.7; "(k|epsilon|omega)" 0.7; e 0.7; h 0.7; } } User has an option to edit the "fvSchemes" as well depending on problem statement. Best Luck! |
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August 9, 2018, 07:52 |
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#29 | |
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Sunil
Join Date: Aug 2016
Posts: 7
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Quote:
In this case, does it mean that divergence scheme Gauss linearUpwind uses the gradient scheme of respective variables? Thanks, Sunil. |
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August 9, 2018, 08:23 |
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#30 | |
Senior Member
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Quote:
Yes, you are right. It can either use specific scheme listed in the gradient section or just use default scheme. You can also specify your name for the scheme to use it with several variables, for example like this: Code:
gradSchemes { default none; grad(DDD) cellLimited Gauss linear 1; grad(p) leastSquares; } divSchemes { default none; div(phi,epsilon) Gauss linearUpwind grad(DDD); div(phi,k) Gauss linearUpwind grad(DDD); div(phi,U) Gauss linearUpwind grad(DDD); }
__________________
Best regards, Dr. Alexander VAKHRUSHEV Christian Doppler Laboratory for "Metallurgical Applications of Magnetohydrodynamics" Simulation and Modelling of Metallurgical Processes Department of Metallurgy University of Leoben http://smmp.unileoben.ac.at |
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August 9, 2018, 08:39 |
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#31 |
New Member
Sunil
Join Date: Aug 2016
Posts: 7
Rep Power: 10 |
Great. Thanks a lot Dr. Vakhrushev.
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