CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

Floating point exception and increasing corruant numbers

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 5, 2022, 14:55
Question Floating point exception and increasing corruant numbers
  #1
New Member
 
Join Date: Aug 2022
Posts: 6
Rep Power: 4
Eman Eal is on a distinguished road
I am attempting to set up my first real simulation after doing several tutorials.
Currently I have successfully created a mesh for my system. In the end I will need a fairly complicated system but currently I am just attempting to get the simulation to run and am planning to add in features one at a time.
Currently I am attempting to simulate incompressible flow in a region that is adjacent to a spinning shaft.
I can get the simulation to run successfully if I don't have the wall rotating but if I add any conditions that would cause motion in the region my corruant number quickly grows, and then after a point I get the following error.

Time = 0.005s

Courant Number mean: 0.0642621 max: 1.20394
#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/lib/x86_64-linux-gnu/libc.so.6"
#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 ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#7 ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#8 ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#9 ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/icoFoam"
#10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#11 ? in "/opt/openfoam10/platforms/linux64GccDPInt32Opt/bin/icoFoam"
Floating point exception (core dumped)

I assume that my simulation is set up incorrectly. Does anyone have experience with similar errors?

This is my U file at 0:

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 10
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
symPlane
{
type symmetryPlane;
}

hotInlet
{
type zeroGradient;
}

coldInlet
{
type zeroGradient;
//value uniform (0 0 -.001);
}

circOutlet
{
type zeroGradient;
}

axialOutlet
{
type zeroGradient;
}

rotatingWall
{
// type noSlip;
type rotatingWallVelocity;
origin (0 0 -20);
axis (0 1 0);
omega 0.1;
}

staticWall
{
type noSlip;
}

defaultFaces
{
type empty;
}
}

my controlDict:
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 10
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "system";
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application icoFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 1;

deltaT .001;

writeControl runTime;

writeInterval 1;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;

}
/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 10
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "system";
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application icoFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 1;

deltaT .001;

writeControl runTime;

writeInterval 1;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;

}


my fvSchemes:

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 10
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "system";
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
default steadyState;
}

gradSchemes
{
default leastSquares;
}

divSchemes
{
default none;
div(phi,U) Gauss linearUpwind grad(U);
//div(div(phi,U)) Gauss linear;
}

laplacianSchemes
{
default Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}


and my fvSolutions:

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 10
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
p
{
solver PCG;
preconditioner DIC;
tolerance 1e-06;
relTol 0.05;
}

// pFinal
// {
// $p;
// relTol 0;
// }

U
{
solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-05;
relTol 0;
}
}

PISO
{
nCorrectors 2;
nNonOrthogonalCorrectors 0;
pRefCell 0;
pRefValue 0;
}

I have an image of the mesh but am having trouble uploading it to this post because it asks for a url, does anyone know a good way to do this?

I suspect that the issue is linked to the fact that the corruant number increases every time step until it becomes larger than 1.
I have also tried simply defining a slow flow from one of the inlets and that causes a similar error. I tried a few divergence schemes as well but that just changed when the error occurred. I am hoping that I have committed some common rookie mistake so I figured I would ask for help.
Eman Eal is offline   Reply With Quote

Reply

Tags
beginner, courant, error


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Floating Point Exception Error nyox FLUENT 11 November 30, 2018 13:31
icoFoam floating point exception (8) leizhao512 OpenFOAM Running, Solving & CFD 7 November 1, 2018 12:43
FATAL: floating point exception (AMG divergence) KeganLeckness FLUENT 1 December 2, 2015 12:10
Help with solving floating point exception crash. rendagar Main CFD Forum 1 March 26, 2014 08:34
Floating point error and divergence detected aannjj FLUENT 0 July 2, 2013 04:44


All times are GMT -4. The time now is 12:45.