[hssnjfry]

hi
when i try to solve my project after 10 time solving stoped and say like below

Time = 10

smoothSolver: Solving for Ux, Initial residual = 2.33919e-06, Final residual = 1.83275e-07, No Iterations 1
smoothSolver: Solving for Uy, Initial residual = 2.73437e-07, Final residual = 2.73437e-07, No Iterations 0
#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::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 ? at ??:?
#9 ? at ??:?
#10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#11 ? at ??:?
Floating point exception (core dumped)

why this happened and what i should to do?

[coolcrasher]

I suppose there is not sufficient space in your drive to run your simulation or to write the results.
Make space and run the simulation again. Check if this works

[hssnjfry]

i have 100 GB space but number of mesh is 32000 and ram is 3GB and my cpu is core 2duo but my procces is 2D.youn thinck my system is weak to run that?

[alexeym]

Hi,

Usually this means diverging solution. What should you do? It depends on the result you would like to achieve.

Start with checkMesh. If mesh is OK, you can change GAMG solver for pressures equation to PCG in fvSolution. Then you can check you relaxation factors.

If these steps do not help, you can either describe your case, post case files here (tar.gz archive of case folder), or (if you not allowed to post case files) describe your case, post boundary conditions you are using, post checkMesh output.

(And in general this error has nothing to do with free disk space)

[hssnjfry]

hi my file is here please check that

[alexeym]

Yeah. Checked.

[hssnjfry]

hi sorry you can download now here

[alexeym]

And you really think this is better? You have plenty of choices: attache your small archive to the message here, put your case files on github, put your case files on bitbucket, put your files on Dropbox, put your files on Box, well there are A LOT of places where you can store legal content without all these pauses and banners.

Also as I said, you need to describe your case. Surely I can try to guess what you are trying to simulate, ask more questions, wait for the answers, ask even more questions. Yet it would be MUCH MORE easier if you describe the case yourself. Somehow you have missed "describe your case" clause in my answer.

[hssnjfry]

hi i fixed link
my describe case
i want to simulation a train 2D and calculation drag and turbulent parameter
my boundary is inlet: pached oulet: pached topbottom:wall train:wall frontback:empty
file in 0 folder is
for U
boundaryField
{
inlet
{
type fixedValue;
value uniform (15 0 0);
}

outlet
{
type zeroGradient;
}

topbottom
{
type fixedValue;
value uniform (0 0 0);
}

train
{
type fixedValue;
value uniform (0 0 0);
}

frontback
{
type empty;
}
}

for P
boundaryField
{
inlet
{
type zeroGradient;
}

outlet
{
type fixedValue;
value uniform 0;
}

topbottom
{
type zeroGradient;
}

train
{
type zeroGradient;
}

frontback
{
type empty;
}
}
for nut
internalField uniform 0;

boundaryField
{
inlet
{
type calculated;
value uniform 0;
}
outlet
{
type calculated;
value uniform 0;
}
topbottom
{
type nutkWallFunction;
value uniform 0;
}
train
{
type nutkWallFunction;
value uniform 0;
}
frontback
{
type empty;
}
}
for k
dimensions [0 2 -2 0 0 0 0];

internalField uniform 0.844;

boundaryField
{
inlet
{
type fixedValue;
value uniform 0.844;
}
outlet
{
type zeroGradient;
}
topbottom
{
type kqRWallFunction;
value uniform 0.844;
}
train
{
type kqRWallFunction;
value uniform 0.844;
}
frontback
{
type empty;
}
}

for epsilon

boundaryField
{
inlet
{
type fixedValue;
value uniform 40.4;
}
outlet
{
type zeroGradient;
}
topbottom
{
type epsilonWallFunction;
value uniform 40.4;
}
train
{
type epsilonWallFunction;
value uniform 40.4;
}
frontback
{
type empty;
}
}

transportModel Newtonian;

nu nu [ 0 2 -1 0 0 0 0 ] 1e-05;

CrossPowerLawCoeffs
{
nu0 nu0 [ 0 2 -1 0 0 0 0 ] 1e-06;
nuInf nuInf [ 0 2 -1 0 0 0 0 ] 1e-06;
m m [ 0 0 1 0 0 0 0 ] 1;
n n [ 0 0 0 0 0 0 0 ] 1;
}

BirdCarreauCoeffs
{
nu0 nu0 [ 0 2 -1 0 0 0 0 ] 1e-06;
nuInf nuInf [ 0 2 -1 0 0 0 0 ] 1e-06;
k k [ 0 0 1 0 0 0 0 ] 0;
n n [ 0 0 0 0 0 0 0 ] 1;
}


// ************************************************** *********************** //
object controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application simpleFoam;

startFrom latestTime;

startTime 0;

stopAt endTime;

endTime 2000;

deltaT 1;

writeControl timeStep;

writeInterval 100;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression off;

timeFormat general;

timePrecision 6;

runTimeModifiable true;


FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
default steadyState;
}

gradSchemes
{
default Gauss linear;
}

divSchemes
{
default none;
div(phi,U) bounded Gauss linearUpwind grad(U);
div(phi,k) bounded Gauss linearUpwind grad(k);
div(phi,epsilon) bounded Gauss linearUpwind grad(epsilon);
div(phi,R) bounded Gauss upwind;
div(R) Gauss linear;
div(phi,nuTilda) bounded Gauss upwind;
div((nuEff*dev(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
default Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}

fluxRequired
{
default no;
p ;
}


FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
p
{
solver GAMG;
tolerance 1e-06;
relTol 1e-06;
smoother GaussSeidel;
nPreSweeps 0;
nPostSweeps 2;
cacheAgglomeration on;
agglomerator faceAreaPair;
nCellsInCoarsestLevel 10;
mergeLevels 1;
}

"(U|k|epsilon|R|nuTilda)"
{
solver smoothSolver;
smoother symGaussSeidel;
tolerance 1e-06;
relTol 1e-6;
}
}

SIMPLE
{
nNonOrthogonalCorrectors 0;
}

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


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

[RodriguezFatz]

You patch inlet and outlet? Are you sure you have 100% the same flux? How does that work? If there is just any small difference your simulation will blow up.

Also: How can your residuals be that low after just 10 iterations of SIMPLE?

[hssnjfry]

hi
actually i want simulate a train in open air like airfoil
are you have better boundary condition for that ?i designed my shape in salome with dimension mm and meshed in that,is that need when export to openfoam consider translation scale or not ?
and i dont no how residuals be that low after just 10 iterations.i think maybe my epsilon is very high like 40 and k is 4 .

[RodriguezFatz]

What do you use for patching?
If you run checkMesh I think the physical dimensions of the grid are shown. You can see there if this is correct.

[hssnjfry]

i use this order to convert mesh in salome to openfoam ideasUnvToFoam Mesh_1.unv then checkmesh and sayed ok

[RodriguezFatz]

I am not sure if that is an answer to my post...
If you run checkMesh it says "Overall domain bounding box..." in one line.
What does say inside the brackets ( xxxx ) ( xxxx)?

[hssnjfry]

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.4.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 2.4.0-f0842aea0e77
Exec : checkMesh
Date : Oct 06 2015
Time : 17:48:10
Host : "hssn"
PID : 4255
Case : /home/hssn/Desktop/DNS/tryop
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

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

--> FOAM Warning :
From function checkMesh
in file db/Time/timeSelector.C at line 262
No time specified or available, selecting 'constant'
Create polyMesh for time = constant

Time = constant

Mesh stats
points: 22331
faces: 177246
internal faces: 145582
cells: 80707
faces per cell: 4
boundary patches: 5
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 0
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 80707
polyhedra: 0

Checking topology...
Boundary definition OK.
Cell to face addressing OK.
Point usage OK.
Upper triangular ordering OK.
Face vertices OK.
Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces...
Patch Faces Points Surface topology
inlet 102 104 ok (non-closed singly connected)
topbottom 672 676 ok (non-closed singly connected)
frontback 18292 10386 ok (non-closed singly connected)
outlet 102 104 ok (non-closed singly connected)
train 12496 7054 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (-13.064 -1.25179 0.003) (-11.564 -0.801795 0.013)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Boundary openness (-1.12574e-19 -9.56173e-18 9.14914e-16) OK.
Max cell openness = 2.83931e-16 OK.
Max aspect ratio = 12.4271 OK.
Minimum face area = 3.85e-08. Maximum face area = 0.00252149. Face area magnitudes OK.
Min volume = 6.54628e-12. Max volume = 8.40498e-06. Total volume = 0.00660707. Cell volumes OK.
Mesh non-orthogonality Max: 75.4738 average: 20.8571
*Number of severely non-orthogonal (> 70 degrees) faces: 54.
Non-orthogonality check OK.
<<Writing 54 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
Max skewness = 0.808257 OK.
Coupled point location match (average 0) OK.

Mesh OK.

End

[RodriguezFatz]

Now your brain comes into play!
The bounding box shows the size of your domain. From (x1, y1, z1) to (x2, y2, z2). So does that make sense that x goes from -13.064 to -11.564, thus having an x-length of about 1.5 meters?

[hssnjfry]

yes my x length is 1.5 meter but i set salome to mm and i think that enough to recognized by openfoam.
i use transport scale to convert meter to mm but same error happened.i attached my filehere you can see that.i think my boundary is problem

[RodriguezFatz]

I don't understand you.

[hssnjfry]

i fixed errore before.

i solved model by SpalartAllmaras but when used k-epsilon model residual in Iteration 8 for k and epsilon as below

smoothSolver: Solving for epsilon, Initial residual = 1, Final residual = 6.30323e-07, No Iterations 39
smoothSolver: Solving for k, Initial residual = 1, Final residual = 8.58102e-07, No Iterations 10
bounding k, min: -1.29847e+22 max: 1.98718e+33 average: 7.76856e+28

i want now way this happened? this is major question .

[RodriguezFatz]

I can't understand your english, sorry. Maybe someone else understands this.