[jishnusoni]

Hello,

I am trying to simulate an Impinging jet. I have created geometry and meshed it in Salome and transfered in the Openfoam using IdeasUnvToFoam.

I am getting this error after few time iterations:

Time = 0.205425

DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 0.0266363, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 0.0300905, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 0.0434508, No Iterations 1
DICPCG: Solving for p, Initial residual = 0.913357, Final residual = 0.00844998, No Iterations 5
time step continuity errors : sum local = 1.88172e+57, global = 3.94684e+45, cumulative = 3.94684e+45
DILUPBiCG: Solving for epsilon, Initial residual = 1, Final residual = 0.0502332, No Iterations 17
DILUPBiCG: Solving for k, Initial residual = 2.0615e-20, Final residual = 2.0615e-20, No Iterations 0
ExecutionTime = 588.83 s ClockTime = 589 s

Time = 0.206338

DILUPBiCG: Solving for Ux, Initial residual = 0.436017, Final residual = 0.0316758, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.403818, Final residual = 0.0338512, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.491748, Final residual = 0.0305268, No Iterations 1
DICPCG: Solving for p, Initial residual = 1, Final residual = 208.867, No Iterations 1001
time step continuity errors : sum local = 4.23244e+62, global = 1.42026e+59, cumulative = 1.42026e+59
#0 Foam::error:rintStack(Foam::Ostream&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib/libc.so.6"
#3 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#4 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so"
#5 Foam::lduMatrix::solverPerformance Foam::solve<double>(Foam::tmp<Foam::fvMatrix<doubl e> > const&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#6 Foam::incompressible::RASModels::kEpsilon::correct () in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#7 main in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/applications/bin/linux64GccDPOpt/simpleFoam"
#8 __libc_start_main in "/lib/libc.so.6"
#9 _start at /build/buildd/eglibc-2.10.1/csu/../sysdeps/x86_64/elf/start.S:116
Floating point exception

Can someone please help me. I have attached my case with this message.

thanks in advance

regards
jish

[linnemann]

Hi

This does not look right.

DILUPBiCG: Solving for k, Initial residual = 2.0615e-20, Final residual = 2.0615e-20, No Iterations 0

Maybe you should switch u/k/e to smoothSolver and p to GAMG, and set a min iteration number to 1 on k.

         p GAMG
     {
         tolerance       1e-07;
         relTol          0.01;
         smoother        GaussSeidel;
         cacheAgglomeration true;
         nCellsInCoarsestLevel 100;
         agglomerator    faceAreaPair;
         mergeLevels     1;
        minIter          0;
        maxIter          2000;
     };



k smoothSolver
    {
        smoother        GaussSeidel;
        nSweeps         1;
        tolerance       1e-06;
        relTol          0.1;
        minIter          1;
        maxIter          2000;
    };

[jishnusoni]

Hello Linnemann,

I have tried to apply your changes in the fvsolutions, but its showing me a fatal error.

Can you please tell me where to apply these changes?

thanks

/jish

[jishnusoni]

Further information,

I am using SimpleFoam to compute these and at high Re of 10000.

/jish

[linnemann]

Hi it should be applied in you fvSolution file

are you using 1.6 or 1.5-dev?

I dont remember if 1.6 supports the minIter/maxIter but you could try and comment these if it throws an error.

Can you post the error since I don't have a whole lot to work with when I don't know the error.

[jishnusoni]

Hi,

I am using OpenFoam 1.6. I tried to change the fvsolution as you mentioned but I got another error.

*first full error which I got when I was trying to simulate is this:

Time = 0.205425

DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 0.0266363, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 0.0300905, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 0.0434508, No Iterations 1
DICPCG: Solving for p, Initial residual = 0.913357, Final residual = 0.00844998, No Iterations 5
time step continuity errors : sum local = 1.88172e+57, global = 3.94684e+45, cumulative = 3.94684e+45
DILUPBiCG: Solving for epsilon, Initial residual = 1, Final residual = 0.0502332, No Iterations 17
DILUPBiCG: Solving for k, Initial residual = 2.0615e-20, Final residual = 2.0615e-20, No Iterations 0
ExecutionTime = 587.78 s ClockTime = 588 s

Time = 0.206338

DILUPBiCG: Solving for Ux, Initial residual = 0.436017, Final residual = 0.0316758, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 0.403818, Final residual = 0.0338512, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 0.491748, Final residual = 0.0305268, No Iterations 1
DICPCG: Solving for p, Initial residual = 1, Final residual = 208.867, No Iterations 1001
time step continuity errors : sum local = 4.23244e+62, global = 1.42026e+59, cumulative = 1.42026e+59
#0 Foam::error:rintStack(Foam::Ostream&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib/libc.so.6"
#3 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#4 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so"
#5 Foam::lduMatrix::solverPerformance Foam::solve<double>(Foam::tmp<Foam::fvMatrix<doubl e> > const&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#6 Foam::incompressible::RASModels::kEpsilon::correct () in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#7 main in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/applications/bin/linux64GccDPOpt/simpleFoam"
#8 __libc_start_main in "/lib/libc.so.6"
#9 _start at /build/buildd/eglibc-2.10.1/csu/../sysdeps/x86_64/elf/start.S:116
Floating point exception



The second error after applying your changes in the fvsolutions are:


/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.6.x |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 1.6.x-47a041d77269
Exec : simpleFoam
Date : Mar 18 2010
Time : 13:08:16
Host : jish-laptop
PID : 3244
Case : /home/jish/Desktop/impingingjet
nProcs : 1
SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

// using new solver syntax:
p
{
solver GAMG;
tolerance 1e-07;
relTol 0.01;
smoother GaussSeidel;
cacheAgglomeration true;
nCellsInCoarsestLevel 100;
agglomerator faceAreaPair;
mergeLevels 1;
minIter 0;
maxIter 2000;
}

// using new solver syntax:
U
{
solver smoothSolver;
smoother GaussSeidel;
nSweeps 1;
tolerance 1e-06;
relTol 0.1;
minIter 1;
maxIter 2000;
}

// using new solver syntax:
epsilon
{
solver smoothSolver;
smoother GaussSeidel;
nSweeps 1;
tolerance 1e-06;
relTol 0.1;
minIter 1;
maxIter 2000;
}

Reading field p

Reading field U

Reading/calculating face flux field phi



--> FOAM FATAL IO ERROR:
keyword SIMPLE is undefined in dictionary "/home/jish/Desktop/impingingjet/system/fvSolution"

file: /home/jish/Desktop/impingingjet/system/fvSolution from line 20 to line 93.

From function dictionary::subDict(const word& keyword) const
in file db/dictionary/dictionary.C at line 457.

FOAM exiting




Can you give me any suggestions.

/jish

[linnemann]

Hi

Yup your parenthesis are not defined properly.

Check for matching parenthesis.

Something is cutting the dict reader before it hits the SIMPLE keyword.

[jishnusoni]

I am attaching my fvsolution, can you check it and tell me whats wrong, because I am trying, but keep getting the errors.

/jish

[linnemann]

Hi you are missing the semicolon a few places, this is C++ so you have to be sure that you have ; at the right places

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.6                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p GAMG
     {
    tolerance       1e-07;
        relTol          0.01;
        smoother        GaussSeidel;
        cacheAgglomeration true;
        nCellsInCoarsestLevel 100;
        agglomerator    faceAreaPair;
        mergeLevels     1;
        minIter          0;
        maxIter          2000;
     };


    U smoothSolver
    {
    smoother        GaussSeidel;
        nSweeps         1;
        tolerance       1e-06;
        relTol          0.1;
        minIter          1;
        maxIter          2000;
    }; // there was one missing here

    k smoothSolver
    {
    smoother        GaussSeidel;
        nSweeps         1;
        tolerance       1e-06;
        relTol          0.1;
        minIter          1;
        maxIter          2000;
    };

    epsilon smoothSolver
    {
    smoother        GaussSeidel;
        nSweeps         1;
        tolerance       1e-06;
        relTol          0.1;
        minIter         1;
        maxIter         2000;
    }; // there was one missing here

    R
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-05;
        relTol          0.1;
    }; // there was one missing here

    nuTilda
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-05;
        relTol          0.1;
    }; // there was one missing here
}

SIMPLE
{
    nNonOrthogonalCorrectors 0;
}

relaxationFactors
{
    p               0.3;
    U               0.7;
    k               0.7;
    epsilon         0.7;
    R               0.7;
    nuTilda         0.7;
}


// ************************************************************************* //

[jishnusoni]

hi
I am still getting error.

Time = 0.166166

smoothSolver: Solving for Ux, Initial residual = 0.0275854, Final residual = 0.00146647, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 0.0718824, Final residual = 0.000758482, No Iterations 2
smoothSolver: Solving for Uz, Initial residual = 0.968862, Final residual = 0.0409947, No Iterations 2
GAMG: Solving for p, Initial residual = 0.938635, Final residual = 0.00441988, No Iterations 1
time step continuity errors : sum local = 8.94404e+39, global = 1.23604e+35, cumulative = 1.15359e+35
smoothSolver: Solving for epsilon, Initial residual = 0.169669, Final residual = 1.73112e-23, No Iterations 1
bounding epsilon, min: -1.07468e+84 max: 1.76614e+89 average: 4.16457e+85
smoothSolver: Solving for k, Initial residual = 1.18578e-06, Final residual = 1.52363e-07, No Iterations 1
bounding k, min: -1.08842e+59 max: 8.52353e+80 average: 4.05931e+77
ExecutionTime = 1135.36 s ClockTime = 1136 s

Time = 0.167079

smoothSolver: Solving for Ux, Initial residual = 0.570872, Final residual = 0.0457938, No Iterations 3
smoothSolver: Solving for Uy, Initial residual = 0.958293, Final residual = 0.0716294, No Iterations 3
smoothSolver: Solving for Uz, Initial residual = 0.999977, Final residual = 0.0660372, No Iterations 3
#0 Foam::error:rintStack(Foam::Ostream&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib/libc.so.6"
#3 Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#4 Foam::GAMGSolver::solveCoarsestLevel(Foam::Field<d ouble>&, Foam::Field<double> const&) const in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#5 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::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#6 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libOpenFOAM.so"
#7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/lib/linux64GccDPOpt/libfiniteVolume.so"
#8 main in "/home/jish/OpenFOAM/OpenFOAM-1.6.x/applications/bin/linux64GccDPOpt/simpleFoam"
#9 __libc_start_main in "/lib/libc.so.6"
#10 _start at /build/buildd/eglibc-2.10.1/csu/../sysdeps/x86_64/elf/start.S:116
Floating point exception


I have implemented your changes but after few iterations its still showing me the above error.

I am attching my case again, let me know if there is anything wrong with the whole case.

/jish

[linnemann]

Hi

You can see that k/epsilon is exploding as well as the time step continuity errors.

The case setup should be ok, but here is something wrong with your initial boundary conditions or the scale of the mesh. Otherwise k/epsilon should not blow up like this.

on a sidenote, if you are using simpleFoam deltaT should be 1. simpleFoam is a steady-state solver so no need to have a small deltaT.

[jishnusoni]

Hi,

Do you think that the wall functions is creating this error. As I have tried to use the boundary condition similar to the pitzDaily tutorial. Does the kqRwallfunction and nutwallfunction, epsilonWallfunction causing the error?

I have attached the boundary condition files let me know what would be potentially wrong.

/jish

[maysmech]

Originally Posted by linnemann

on a sidenote, if you are using simpleFoam deltaT should be 1. simpleFoam is a steady-state solver so no need to have a small deltaT.

Hi,
Is it possible to describe more about role of deltaT. is it mean its magnitude has no effect on results accuracy?