CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM Running, Solving & CFD (http://www.cfd-online.com/Forums/openfoam-solving/)
-   -   potentialFoam giving strange error when initialising simpleFoam (http://www.cfd-online.com/Forums/openfoam-solving/124757-potentialfoam-giving-strange-error-when-initialising-simplefoam.html)

maero21 October 12, 2013 06:40

potentialFoam giving strange error when initialising simpleFoam
 
3 Attachment(s)
Dear OpenFOAM users,

I want to run a 3D simulation of a double element wing with endplates. The mesh is around 5 million cells. However when I run simpleFoam it will immediately diverge. Therefore I want to initialize the simpleFoam run by first running potentialFoam. However, I keep getting a very strange error which does not give me any information:

Code:

Calculating potential flow
#0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1  Foam::sigFpe::sigHandler(int) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2  in "/lib/x86_64-linux-gnu/libc.so.6"
#3  Foam::adjustPhi(Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh>&, Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&) in "/opt/openfoam221/platforms/linux64GccDPOpt/lib/libfiniteVolume.so"
#4 
 in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/potentialFoam"
#5  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#6 
 in "/opt/openfoam221/platforms/linux64GccDPOpt/bin/potentialFoam"
Floating point exception (core dumped)

I have attached my fvSolution, fvSchemes and controlDict.

I hope someone has had this error before and knows what to do.

By the way, I am running OpenFoam 2.1.1.

wyldckat October 12, 2013 14:41

Greetings maero21,

"sigFpe" means this: http://en.wikipedia.org/wiki/SIGFPE#SIGFPE
Quote:

The SIGFPE signal is sent to a process when it executes an erroneous arithmetic operation, such as division by zero (the FPE stands for floating point error).
In the line below that it says that it was running the method "adjustPhi". Therefore, something very wrong is happening with the pressure values and/or flow velocity, since it triggered a division by zero.

This usually has to do with bad boundary conditions or a damaged mesh. You can use checkMesh to ascertain the quality of the mesh:
Code:

checkMesh -allTopology -allGeometry
Best regards,
Bruno

maero21 October 15, 2013 11:47

Thank you! Indeed the mesh failed 1 mesh check. It says that it has found "cells with small determinant". I am guessing that is the reason it divides something by 0 in the solving.
How can I see those small determinant cells? I have generated the mesh in Pointwise, but apparently Pointwise is not good with 3D meshes? That would be strange, right?

wyldckat October 15, 2013 16:19

Quick answer:
Code:

foamToVTK -cellSet nameOfCellSetIndicatedByCheckMesh


All times are GMT -4. The time now is 02:08.