[sara]

Hi everyone
I'm just starting with OpenFOAM. I want to simulate oil mist filtration and I chose the solver twoPhaseEulerFoam.
After changing some of the files and filling in my parameters I run the calculation. Then I get this error message:

DILUPBiCG: Solving for alpha, Initial residual = 1, Final residual = 7.5185e-14, No Iterations 3
Dispersed phase volume fraction = 5.09482e-08 Min(alpha) = 0 Max(alpha) = 0.0005236
DILUPBiCG: Solving for alpha, Initial residual = 0.00235546, Final residual = 1.54916e-13, No Iterations 2
Dispersed phase volume fraction = 5.09482e-08 Min(alpha) = -3.26858e-18 Max(alpha) = 0.0005236
#0 Foam::error::printStack(Foam:stream&) in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#2 Uninterpreted: [0xb7f9d420]
#3 Foam::DICPreconditioner::calcReciprocalD(Foam::Fie ld<double>&, Foam::lduMatrix const&) in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#4 Foam::DICSmoother::DICSmoother(Foam::word const&, Foam::lduMatrix const&, Foam::FieldField<foam::field,> const&, Foam::FieldField<foam::field,> const&, Foam::UPtrList<foam::lduinterfacefield> const&) in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#5 Foam::lduMatrix::smoother::addsymMatrixConstructor ToTable<foam::dicsmoother>::Ne w(Foam::word const&, Foam::lduMatrix const&, Foam::FieldField<foam::field,> const&, Foam::FieldField<foam::field,> const&, Foam::UPtrList<foam::lduinterfacefield> const&) in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#6 Foam::lduMatrix::smoother::New(Foam::word const&, Foam::lduMatrix const&, Foam::FieldField<foam::field,> const&, Foam::FieldField<foam::field,> const&, Foam::UPtrList<foam::lduinterfacefield> const&, Foam::Istream&) in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#7 Foam::GAMGSolver::initVcycle(Foam::PtrList<foam::f ield<double> >&, Foam::PtrList<foam::field<double> >&, Foam::PtrList<foam::ldumatrix::smoother>&) const in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#8 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libOpenFOAM.so"
#9 Foam::fvMatrix<double>::solve(Foam::Istream&) in "/home/schairer/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt/libfiniteVolume.so"
#10 main in "/home/schairer/OpenFOAM/OpenFOAM-1.5/applications/bin/linuxGccDPOpt/twoPhaseEul erFoam"
#11 __libc_start_main in "/lib/tls/i686/cmov/libc.so.6"
#12 Foam::regIOobject::readIfModified() in "/home/schairer/OpenFOAM/OpenFOAM-1.5/applications/bin/linuxGccDPOpt/twoPhaseEul erFoam"
Floating point exception

Does anybody know what this is about? I didn't change anything in the directories mentioned in there.
I'd be grateful for some help.
Cheers, Sara

[dmoroian]

Hi Sara,
The listing says:

...
#7 Foam::GAMGSolver::...
...

which I think complains about your pressure field that could not be resolved (GAMG is usually used for solving the pressure equation).
So it seems there is something wrong with your pressure settings (boundary conditions, initial conditions).

I hope this is helpful,
Dragos

[sara]

Hi Drago
Maybe it was. I changed alpha, too. Because it was set to 0 in the internal field and I thought that maybe somewhere during the calculation it tried to divide by zero.
In the p file I only changed the expression of the value from 1e+05 to 100000.
And I changed zeroGradient for the boundaries to fixedValue...
At least it works now, though I'm not sure if it's doing what I want it to do ;)
Anyway, thanks a lot for the quick answer.
Cheers, Sara