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-   -   Parallel Run problem (http://www.cfd-online.com/Forums/openfoam-solving/74490-parallel-run-problem.html)

shhe April 1, 2010 10:47

Parallel Run problem
 
I have a problem with running firefoam in parallel. Working with serial there is no problem. With parallel, I encountered a problem after writing two or three data set the program stopped and exit and give the following statments:

#0 Foam::error::printStack(Foam::Ostream&) in "/home/shhe/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/shhe/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ??smoothSolver: Solving for Uz, Initial residual = 0.00703829, Final residual = 5.77079e-09, No Iterations 8
DILUPBiCG: Solving for ft, Initial residual = 0.00165804, Final residual = 4.86177e-10, No Iterations 3
max(ft) = 1
min(ft) = -3.744e-09
in "/lib64/libc.so.6"
#3 Foam::GaussSeidelSmoother::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)max(ftVar) = 0.0341966
min(ftVar) = 1.3266e-128
in "/home/shhe/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#4 Foam::GaussSeidelSmoother::smooth(Foam::Field<doub le>&, Foam::Field<double> const&, unsigned char, int) const in "/home/shhe/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#5 Foam::smoothSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) constDILUPBiCG: Solving for ft, Initial residual = 0.00185502, Final residual = 9.89006e-10, No Iterations 3
max(ft) = 1
min(ft) = -4.84243e-07
in "/home/shhe/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#6 GAMG: Solving for pd, Initial residual = 0.0173815, Final residual = 6.79687e-09, No Iterations 13
max(ftVar) = 0.0340001
min(ftVar) = 9.06034e-141
diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
Foam::fvMatrix<Foam::Vector<double> >::solve(Foam::dictionary const&)time step continuity errors : sum local = 1.79503e-11, global = -8.99262e-13, cumulative = 0.000116242
in "/home/shhe/OpenFOAM/shhe-1.6/applications/bin/linux64GccDPOpt/fireFoam"
#7 smoothSolver: Solving for k, Initial residual = 0.00373242, Final residual = 4.77105e-09, No Iterations 6
mainExecutionTime = 1301.07 s ClockTime = 1311 s

in "/home/shhe/OpenFOAM/shhe-1.6/applications/bin/linux64GccDPOpt/fireFoam"
#8 __libc_start_mainCourant Number mean: 0.0316383 max: 0.505215
deltaT = 0.00146301
Time = 0.185297
in "/lib64/libc.so.6"
#9 diagonal: Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
Foam::regIOobject::writeObject(Foam::IOstream::str eamFormat, Foam::IOstream::versionNumber, Foam::IOstream::compressionType) constDILUPBiCG: Solving for ft, Initial residual = 0.00166794, Final residual = 4.49196e-10, No Iterations 3
max(ft) = 1
min(ft) = -5.56997e-09
in "/home/shhe/OpenFOAM/shhe-1.6/applications/bin/linux64GccDPOpt/fireFoam"
max(ftVar) = 0.0345528
min(ftVar) = 9.88153e-128
19253 (n1) exited due to signal 8



The following is my controlDict:
application fireFoam;

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 20.0;

deltaT 1e-5;

//writeControl adjustableRunTime;
writeControl runTime;
writeInterval 0.1;

purgeWrite 0;

writeFormat ascii;

writePrecision 6;

writeCompression uncompressed;

timeFormat general;

timePrecision 6;

graphFormat raw;

runTimeModifiable yes;
adjustTimeStep yes;

maxCo 0.5;

maxDeltaT 0.01;


and decomposeParDict:

numberOfSubdomains 8;

method simple;
//method metis;
//method scotch;

simpleCoeffs
{
n (2 2 2);
delta 0.001;
}

hierarchicalCoeffs
{
n (1 1 1);
delta 0.001;
order xyz;
}


scotchCoeffs
{
processorWeights
(
1
1
1
1
1
1
1
1


);
}

manualCoeffs
{
dataFile "";
}

distributed no;

roots
(
"<root0>"
"<root1>"
"<root2>"
"<root3>"
"<root4>"
"<root5>"
"<root6>"
"<root7>"


);

fgal April 27, 2010 07:52

Hi,
Your Courant number is of 0.5, I noticed that above 0.45, with most of the schemes I used, fireFoam diverges due to numerical instability. Could you try to reduce your time step by setting the maxCo entry to 0.3 in controlDict ?

Francois


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