I'm trying to run a 2-D vortex
I'm trying to run a 2-D vortex shedding simulation with a circular cylinder in icoFoam. The conditions are u=1 m/s, d = 0.05 m and the comp domain is 1 m in the x direction and 0.5 m in the y-direction.
The BCs are inlet, outlet and symmetric at the top and bottom. I am using a integration time step of 1e-4 with the following schemes: ddtSchemes { default CrankNicholson 0.5; } gradSchemes { default Gauss linear; grad(p) Gauss linear; } divSchemes { default none; div(phi,U) Gauss limitedLinearV 1; } laplacianSchemes { default none; laplacian(nu,U) Gauss linear corrected; laplacian((1|A(U)),p) Gauss linear corrected; } interpolationSchemes { default linear; interpolate(HbyA) linear; } snGradSchemes { default corrected; } fluxRequired { default no; p; } I also used the following solver settings: solvers { p PCG { tolerance 1e-07; relTol 0; preconditioner DIC; }; U smoothSolver { tolerance 1e-07; relTol 0; smoother GaussSeidel; nSweeps 1; }; } PISO { momentumPredictor yes; nCorrectors 2; nNonOrthogonalCorrectors 2; pRefCell 0; pRefValue 0; } Before shedding starts, the Courant no blows up and the following message is seen: #0 Foam::error::printStack(Foam:http://www.cfd-online.com/OpenFOAM_D...part/proud.gifstream&) in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #1 Foam::sigFpe::sigFpeHandler(int) in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #2 Uninterpreted: [0xb7f08420] #3 Foam::GaussSeidelSmoother::smooth(Foam::word const&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::Field<double> const&, Foam::FieldField<foam::field,> const&, Foam::UPtrList<foam::lduinterfacefield> const&, unsigned char, int) in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #4 Foam::GaussSeidelSmoother::smooth(Foam::Field<doub le>&, Foam::Field<double> const&, unsigned char, int) const in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"ddtSche mes #5 Foam::smoothSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #6 Foam::fvMatrix<foam::vector<double> >::solve(Foam::Istream&) in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/icoFoam" #7 Foam::lduMatrix::solverPerformance Foam::solve<foam::vector<double> >(Foam::tmp<foam::fvmatrix<foam::vector<double> > > const&) in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/icoFoam" #8 main in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/icoFoam" #9 __libc_start_main in "/lib/i686/libc.so.6" #10 Foam::regIOobject::readIfModified() in "/home/caelinux/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/icoFoam" Until 0.269 sec, the max Courant # is stable at 0.088, and then starts ramping up. I use an unstructured mesh with ~9500 tetrahedral prisms. As the solution develops, the outlet region has high velocity including flow reversal that isn't transported from the cylinder. CheckMesh does not report any errors. What am I doing wrong? Thanks Anant |
BTW, The Reynolds no is approx
BTW, The Reynolds no is approx 350. I am reducing the time step by 10 to see if this overcomes the problem.
Anant |
Email your case/ 0, constant a
Email your case/ 0, constant and system to me, and let me have a look.
Daniel |
what's about your mesh?
Is th
what's about your mesh?
Is the mesh orthogonal enough? |
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