[gara1988]

Hello, I'm trying to find the solution, with simpleFoam, around a wing.

I did the mesh with GMSH, I checked it and it's ok!

When I run simpleFoam, after some time I have this error:

---------------------------------------------------------------------------------------------------------------------------

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.7.x                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 1.7.x-131caa989cd3
Exec   : simpleFoam
Date   : Oct 23 2012
Time   : 14:48:03
Host   : mattia-Satellite-A100
PID    : 4265
Case   : /media/HDE_Mattia/TESI/OpenFoam_SIM/My_OneraM6
nProcs : 1
SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).

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

Create mesh for time = 0

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting RAS turbulence model kEpsilon
kEpsilonCoeffs
{
    Cmu             0.09;
    C1              1.44;
    C2              1.92;
    sigmaEps        1.3;
}


Starting time loop

Time = 1

smoothSolver:  Solving for Ux, Initial residual = 1, Final residual = 0.0156354, No Iterations 4
smoothSolver:  Solving for Uy, Initial residual = 1, Final residual = 0.0147744, No Iterations 4
smoothSolver:  Solving for Uz, Initial residual = 1, Final residual = 0.0141945, No Iterations 4
GAMG:  Solving for p, Initial residual = 1, Final residual = 0.0765887, No Iterations 5
time step continuity errors : sum local = 0.00785526, global = -6.37702e-05, cumulative = -6.37702e-05
DILUPBiCG:  Solving for epsilon, Initial residual = 0.0122775, Final residual = 0.000168175, No Iterations 2
bounding epsilon, min: -5574.49 max: 71373.4 average: 145.518
DILUPBiCG:  Solving for k, Initial residual = 1, Final residual = 0.023163, No Iterations 2
bounding k, min: -147.366 max: 951.351 average: 5.56723
ExecutionTime = 50.28 s  ClockTime = 51 s

Time = 2

smoothSolver:  Solving for Ux, Initial residual = 0.26106, Final residual = 0.00377569, No Iterations 4
smoothSolver:  Solving for Uy, Initial residual = 0.0441241, Final residual = 0.000763274, No Iterations 4
smoothSolver:  Solving for Uz, Initial residual = 0.390185, Final residual = 0.0058094, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.147535, Final residual = 0.0107923, No Iterations 1
time step continuity errors : sum local = 0.053149, global = 0.000500766, cumulative = 0.000436996
DILUPBiCG:  Solving for epsilon, Initial residual = 0.0402059, Final residual = 0.00171671, No Iterations 1
bounding epsilon, min: -121237 max: 5.27191e+06 average: 3535.89
DILUPBiCG:  Solving for k, Initial residual = 0.0747554, Final residual = 0.00241621, No Iterations 2
bounding k, min: -146.836 max: 5643.87 average: 31.7521
ExecutionTime = 78.74 s  ClockTime = 79 s

Time = 3

smoothSolver:  Solving for Ux, Initial residual = 0.247456, Final residual = 0.0206429, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.0387877, Final residual = 0.0032168, No Iterations 2
smoothSolver:  Solving for Uz, Initial residual = 0.343374, Final residual = 0.024948, No Iterations 2
GAMG:  Solving for p, Initial residual = 0.166044, Final residual = 0.0114922, No Iterations 2
time step continuity errors : sum local = 0.0447917, global = 0.000423066, cumulative = 0.000860062
DILUPBiCG:  Solving for epsilon, Initial residual = 0.0555406, Final residual = 0.00191473, No Iterations 1
bounding epsilon, min: -5.39163e+06 max: 5.54757e+08 average: 71838.7
DILUPBiCG:  Solving for k, Initial residual = 0.0707114, Final residual = 0.00186781, No Iterations 2
bounding k, min: -3189.27 max: 154294 average: 95.4119
ExecutionTime = 106.9 s  ClockTime = 107 s

Time = 4

smoothSolver:  Solving for Ux, Initial residual = 0.192757, Final residual = 0.00805001, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.0908262, Final residual = 0.00341814, No Iterations 2
smoothSolver:  Solving for Uz, Initial residual = 0.291972, Final residual = 0.011914, No Iterations 2
GAMG:  Solving for p, Initial residual = 0.463544, Final residual = 0.0389622, No Iterations 2
time step continuity errors : sum local = 0.0852108, global = 0.00132486, cumulative = 0.00218492
DILUPBiCG:  Solving for epsilon, Initial residual = 0.0594854, Final residual = 0.000642822, No Iterations 1
bounding epsilon, min: -8.30055e+09 max: 3.0866e+11 average: 4.61978e+06
DILUPBiCG:  Solving for k, Initial residual = 0.338118, Final residual = 0.00675346, No Iterations 1
bounding k, min: -6.38181e+06 max: 5.92471e+07 average: 1001.34
ExecutionTime = 133.67 s  ClockTime = 134 s

Time = 5

smoothSolver:  Solving for Ux, Initial residual = 0.797821, Final residual = 0.0211082, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.739135, Final residual = 0.0658153, No Iterations 2
smoothSolver:  Solving for Uz, Initial residual = 0.54783, Final residual = 0.0312859, No Iterations 2
GAMG:  Solving for p, Initial residual = 0.424735, Final residual = 0.0249722, No Iterations 2
time step continuity errors : sum local = 7.96186e+10, global = -2.33191e+07, cumulative = -2.33191e+07
DILUPBiCG:  Solving for epsilon, Initial residual = 0.999997, Final residual = 0.0964261, No Iterations 1
bounding epsilon, min: -2.27741e+23 max: 8.88371e+24 average: 4.00346e+19
DILUPBiCG:  Solving for k, Initial residual = 0.999975, Final residual = 0.0152503, No Iterations 1
bounding k, min: -5.98034e+19 max: 4.30253e+20 average: 6.4329e+15
ExecutionTime = 160.39 s  ClockTime = 161 s

Time = 6

smoothSolver:  Solving for Ux, Initial residual = 0.503326, Final residual = 0.0145054, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.516262, Final residual = 0.0087694, No Iterations 2
smoothSolver:  Solving for Uz, Initial residual = 0.663085, Final residual = 0.0268232, No Iterations 2
GAMG:  Solving for p, Initial residual = 0.992137, Final residual = 9.14002e-05, No Iterations 1
time step continuity errors : sum local = 1.55743e+12, global = 4.00732e+10, cumulative = 4.00499e+10
DILUPBiCG:  Solving for epsilon, Initial residual = 9.499e-09, Final residual = 9.499e-09, No Iterations 0
bounding epsilon, min: 5.95232e-21 max: 2.63588e+31 average: 1.74496e+26
DILUPBiCG:  Solving for k, Initial residual = 1, Final residual = 5.60578e-08, No Iterations 1
bounding k, min: -9.87096e+31 max: 4.69593e+33 average: 1.50957e+29
ExecutionTime = 184.34 s  ClockTime = 185 s

Time = 7

smoothSolver:  Solving for Ux, Initial residual = 0.176609, Final residual = 0.00788783, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.00488076, Final residual = 6.44686e-05, No Iterations 2
smoothSolver:  Solving for Uz, Initial residual = 0.062501, Final residual = 0.00183637, No Iterations 2
GAMG:  Solving for p, Initial residual = 2.91086e-11, Final residual = 2.91086e-11, No Iterations 0
time step continuity errors : sum local = 7.19548e+23, global = -3.95748e+09, cumulative = 3.60925e+10
DILUPBiCG:  Solving for epsilon, Initial residual = 6.70065e-12, Final residual = 6.70065e-12, No Iterations 0
bounding epsilon, min: 6.75762e-21 max: 1.83829e+46 average: 6.2131e+40
DILUPBiCG:  Solving for k, Initial residual = 0.137207, Final residual = 0.000197093, No Iterations 2
bounding k, min: -1.8125e+40 max: 1.33333e+43 average: 5.85742e+37
ExecutionTime = 208.37 s  ClockTime = 209 s

Time = 8

smoothSolver:  Solving for Ux, Initial residual = 2.84546e-11, Final residual = 2.84546e-11, No Iterations 0
smoothSolver:  Solving for Uy, Initial residual = 3.46671e-09, Final residual = 3.46671e-09, No Iterations 0
smoothSolver:  Solving for Uz, Initial residual = 4.31442e-11, Final residual = 4.31442e-11, No Iterations 0
#0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#1  Foam::sigFpe::sigFpeHandler(int) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#2  Uninterpreted: 
#3  Foam::GAMGSolver::scalingFactor(Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double> const&, Foam::Field<double> const&) const in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#4  Foam::GAMGSolver::scalingFactor(Foam::Field<double>&, Foam::lduMatrix const&, Foam::Field<double>&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#5  Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMatrix::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 "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#6  Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#7  Foam::fvMatrix<double>::solve(Foam::dictionary const&) in "/opt/openfoam171/lib/linuxGccDPOpt/libfiniteVolume.so"
#8  
 in "/opt/openfoam171/applications/bin/linuxGccDPOpt/simpleFoam"
#9  __libc_start_main in "/lib/i386-linux-gnu/libc.so.6"
#10  
 in "/opt/openfoam171/applications/bin/linuxGccDPOpt/simpleFoam"
Floating point exception (core dumped)

--------------------------------------------------------------------------------------------------------------------------

Is it an error from the numerical scheme? I see that there are a large value for bounding epsilon and k. Is here the problem?

The fvScheme file is:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  1.7.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default         steadyState;
}

gradSchemes
{
    default         Gauss linear;
    grad(p)         Gauss linear;
    grad(U)         Gauss linear;
}

divSchemes
{
    default         none;
    div(phi,U)      Gauss limitedLinear 1;
    div(phi,k)      Gauss limitedLinear 1;
    div(phi,epsilon) Gauss limitedLinear 1;
    div(phi,R)      Gauss limitedLinear 1;
    div(R)          Gauss linear;
    div(phi,nuTilda) Gauss limitedLinear 1;
    div((nuEff*dev(grad(U).T()))) Gauss linear;
}

laplacianSchemes
{
    default         none;
    laplacian(nuEff,U) Gauss linear corrected;
    laplacian((1|A(U)),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;
}

fluxRequired
{
    default         no;
    p               ;
}

Thanks for the replies.
Best regards.

Mattia

[gara1988]

When I turn off turbulence in RAS Properties, It goes ok and the time step continuity errors has no large value. The solution, seen by Paraview, seems ok. How can I correct the problem with epsilon and K.

Thanks.
Best regards.

[yzf1215]

would you please send your Mesh file and your case file to yzf1215@gmail.com? I'm having a similar problem like you.

[gara1988]

Hello, I solved the problem. It was in the turbulence model. I imposed Spalart-Allmras or Realizable K-epsilon and the solution now doesn't diverge!