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February 14, 2013, 04:44 |
Don't understand solver's behaviour
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#1 |
Member
Fabian E.
Join Date: Nov 2009
Posts: 38
Rep Power: 16 |
Hello guys,
today I'm facing a problem, which I can't explain. I have done a dummy calculation for a variable f. f is set everywhere to 1 (boundary/internal). Nevertheless OpenFOAM calculates values differing from 1. Can anyone explain that behaviour to me? Thank you very much in advance. I have a normal transport equation for variable f: Code:
f_( IOobject ( "f", mesh.time().timeName(), mesh, IOobject::MUST_READ, IOobject::AUTO_WRITE ), mesh ), Boundary and internal values all set to 1. Code:
multivariateSurfaceInterpolationScheme<scalar>::fielTable fields; fields.add(f); tmp<fv::convectionScheme<scalar> > convection ( fv::convectionScheme<scalar>::New ( mesh_, fields, phi, mesh_.divScheme("div(phi,f)") ) ); So again keep in mind, for testing purpose I set all values to 1. Now I'm trying to solve the following equations: Code:
Info << "fmin/max = " << min(f_).value() << ", " << max(f_).value() << endl;; tmp<fvScalarMatrix> fEqn ( fvm::ddt(rho, f_) + convection->fvmDiv(phi, f_) - fvm::laplacian(turbulence_->alphaEff(), f_) ); fEqn().relax(); solve(fEqn == rho* fSource); Code:
Info << "fmin/max = " << min(f_).value() << ", " << max(f_).value() << endl;; f min/max = 1, 1 f min/max = 0.90082369, 1.1320949 Schemes: laplacian(alphaEff,f) Gauss linear corrected; div(phi,f) Gauss upwind; RASModel kEpsilon; Last edited by galap; February 14, 2013 at 07:33. |
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February 14, 2013, 05:05 |
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#2 |
Member
Fabian E.
Join Date: Nov 2009
Posts: 38
Rep Power: 16 |
solver used:
solver PBiCG; preconditioner DILU; tolerance 1e-7; relTol 0.01; |
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