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Please excuse for the late reply. Try the following changes in the attachments: Code:
interpolationSchemes Code:
equations - Best Luck! |
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Thanks for the suggestions. I have solved this problem already.I changed the grad schemes to gaussian and others to first order,increased all the relaxations apart from p to 0.7, also there were few problems with bc. However, I am keen on understanding about your suggestion. Changing to linear schemes is clear, it is because of accuracy,but why were you hinting on changing the relaxation factor alone to 0.7??! Is it very evident from the error to do so or how?Thanks. Regards Nagesh |
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Dear Nagesh, Many things you will come to know with experience. In short, I would say that it is more related to theory. _ Best Luck! |
Foam::error::printStack(Foam::Ostream&) at ??:?
Hi all,
I am getting the same error as discussed in above posts .I am pasting what error i am getting. Reading field U Reading/calculating face flux field phi No finite volume options present SIMPLE: no convergence criteria found. Calculations will run for 0.5 steps. Starting time loop Time = 0.005 smoothSolver: Solving for Ux, Initial residual = 0, Final residual = 0, No Iterations 0 smoothSolver: Solving for Uy, Initial residual = 0, Final residual = 0, No Iterations 0 #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>&, double const&, Foam::UList<double> const&) at ??:? #4 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator/<Foam::fvPatchField, Foam::volMesh>(Foam::dimensioned<double> const&, Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > const&) at ??:? #5 ? at ??:? #6 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #7 ? at ??:? Floating point exception (core dumped) Can anybody help me with this . where is the error. Any help will be appreciated.... Regards AJAY |
Hey Ajay,
In my experience this error is often the result of incorrectly initialized values. Check with ur bcs'. It happens when the solver comes across expressions like 0/0 or something that is equally strange. Or your mesh Quality is not good enough. Check with the tool checkMesh. Initial and final residuals=0 is something that I havent come across until now. May be someone else can comment better on these values?! Cheers. |
Nagesh,
Hi were u able to figure out the problem ?? |
Hi,
I am new to OpenFOAM. Currently I'm trying to simulate flow through an S duct and I'm getting the following error when I'm trying to run simpleFoam #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/lib/x86_64-linux-gnu/libpthread.so.0" #3 Foam::GAMGSolver::scale(Foam::Field<double>&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const at ??:? #4 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMa trix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const at ??:? #5 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:? #6 Foam::fvMatrix<double>::solveSegregated(Foam::dict ionary const&) at ??:? #7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) at ??:? #8 Foam::fvMatrix<double>::solve() at ??:? #9 ? at ??:? #10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #11 ? at ??:? Floating point exception (core dumped) Can someone pls explain me where I have gone wrong? Pls help me if you can :( |
See your #1 error. There it says sigFpe error.
It means that you have some variable value which is making 0/0 (divison by zero) form somewhere in your solver. Also you have to check the boundary conditions of your variables in the solver. This error also comes when there are wrong BC. Hope this helps. Best Ajay |
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Thank you Ajay and Tobi.
But I'm not understanding where to check for the 0/0 error or the BC error. I've given in my 0 directory the values for k and epsilon I've calculated and walls have been assigned specific wall criteria. I'm not quite sure where to edit:( |
Hi,
I'm working on a 65mmX65mm inlet and exit, s shaped duct of 90 degree rotation. u=15.79m/s at inlet, pressure 0 at exit. epsilon in 0 file=24.92, k=0.35, nut=4.424e-4, nuTilda=0. In transport properties, nu=1.50934e-5. I'm using pimplefoam for solving the system directories are as below: controldict application pimpleFoam; startFrom latestTime; startTime 0; stopAt endTime; endTime 1; deltaT 0.0001; writeControl adjustableRunTime; writeInterval 0.001; purgeWrite 0; writeFormat ascii; writePrecision 6; writeCompression off; timeFormat general; timePrecision 6; runTimeModifiable yes; adjustTimeStep yes; maxCo 5; fvschemes ddtSchemes { default Euler; } gradSchemes { default Gauss linear; grad(p) Gauss linear; grad(U) Gauss linear; } divSchemes { default none; div(phi,U) bounded Gauss linearUpwind grad(U); div(phi,k) bounded Gauss upwind; div(phi,epsilon) bounded Gauss upwind; div(phi,R) bounded Gauss upwind; div(R) Gauss linear; div(phi,nuTilda) bounded Gauss upwind; div((nuEff*dev2(T(grad(U))))) Gauss linear; } laplacianSchemes { default none; laplacian(nuEff,U) Gauss linear corrected; laplacian(rAUf,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 corrected; } fvsolution solvers { p { solver GAMG; tolerance 1e-7; relTol 0.01; smoother DICGaussSeidel; cacheAgglomeration true; nCellsInCoarsestLevel 10; agglomerator faceAreaPair; mergeLevels 1; } pFinal { $p; relTol 0; } "(U|k|epsilon)" { solver smoothSolver; smoother symGaussSeidel; tolerance 1e-05; relTol 0.1; } "(U|k|epsilon)Final" { $U; relTol 0; } } PIMPLE { nNonOrthogonalCorrectors 0; nCorrectors 2; } Please help if you find any mistake in my calculations or the system properties. I've tried all what I've understood. Not sure why the following error is coming up : PIMPLE: iteration 1 smoothSolver: Solving for Ux, Initial residual = 1, Final residual = 0.0083465, No Iterations 1000 smoothSolver: Solving for Uz, Initial residual = 1, Final residual = 0.0303338, No Iterations 1000 GAMG: Solving for p, Initial residual = 1, Final residual = 1.54301e+34, No Iterations 1000 time step continuity errors : sum local = 2.68132e+31, global = 1.9573e+26, cumulative = 1.9573e+26 GAMG: Solving for p, Initial residual = 0.970831, Final residual = 2.76941e+30, No Iterations 1000 time step continuity errors : sum local = 7.67121e+61, global = 2.29341e+57, cumulative = 2.29341e+57 #0 Foam::error::printStack(Foam::Ostream&) at ??:? #1 Foam::sigFpe::sigHandler(int) at ??:? #2 ? in "/lib/x86_64-linux-gnu/libpthread.so.0" #3 Foam::symGaussSeidelSmoother::smooth(Foam::word const&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::Field<double> const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, unsigned char, int) at ??:? #4 Foam::symGaussSeidelSmoother::smooth(Foam::Field<d ouble>&, Foam::Field<double> const&, unsigned char, int) const at ??:? #5 Foam::smoothSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:? #6 Foam::fvMatrix<double>::solveSegregated(Foam::dict ionary const&) at ??:? #7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) at ??:? #8 Foam::fvMatrix<double>::solve() at ??:? #9 Foam::SolverPerformance<double> Foam::solve<double>(Foam::tmp<Foam::fvMatrix<doubl e> > const&) at ??:? #10 Foam::RASModels::kEpsilon<Foam::IncompressibleTurb ulenceModel<Foam::transportModel> >::correct() at ??:? #11 ? at ??:? #12 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6" #13 ? at ??:? Floating point exception (core dumped) |
Hi,
first of all, please use code tags. The formating of your post is really everything else than readable-friendly. In the first lines of the solver, you can see that you have 1000 iterations for U and p and the final residuals are increasing. This give you the hint that your set-up of the BCs are probably complete wrong and the matrix system you are building and trying to solve has a lot of solutions. Check them, make sure that it is physical. In addition a mesh problem, complete wrong initialization parameters and other stuff can cause this. But having the final residuals going to 1e30 should be a good indicator that there is an fatal mistake (just check the continuity error). Good luck. |
Hi,
Since your sigFpe error is coming in initial iteration there is a high probability that you have some wrong BC in your case which is leading to this error. Also as Tobi mentioned this error also comes when your meshing is wrong. I have encountered this error many times. So, by changing BC, Analyzing your solver code to see if any variable value making 0/0 form there and checking the mesh length and number of divisons made in x and y directions in your blockMeshDict file helps a lot to debug this error. Hope this helps Best Ajay |
Hi,
I simulate the water-gas two phase using interFoam(openfoam3.0.0). But i got a error message. I change the boundary conditions, and try it again and again. It still does not work. There are always the same mistakes(Foam::error...). Could you please help me understand this error? Code:
Courant Number mean: 3.40147e-05 max: 0.502766 |
Why my deltaT is so small? I couldn't understand. It has been bothering me for a long time. I really hope someone here could help me. Thank you.
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