[pajofego]

Hello all,

I've been trying to do some simulations with reactingFoam. I've also used different ODE Solver (SIBS, RK, KRR4) to see if it's possible to get a stable simulation.

Both Solver (RK, KRR4) stops with following error message:

Courant Number mean: 0.0104708 max: 0.394021
deltaT = 3.1361e-05
Time = 0.00293728

Solving chemistry


--> FOAM FATAL ERROR: 
Too many integration steps

    From function ODESolver::solve(const ODE& ode, const scalar  xStart, const scalar xEnd,scalarField& yStart, const scalar eps,  scalar& hEst) const
    in file ODESolvers/ODESolver/ODESolver.C at line 107.

FOAM exiting

The maximum integration steps is hard coded as a constant variable in the source file. Could it make sense to keep it free for the user?

The SIBS Solver stops with following error message:

Solving chemistry


--> FOAM FATAL ERROR: 
attempt to use janafThermo<equationOfState> out of temperature range 200 -> 5000;  T = 187.14

    From function janafThermo<equationOfState>::checkT(const scalar T) const
    in file /home/opencfd/OpenFOAM/OpenFOAM-1.7.x/src/thermophysicalModels/specie/lnInclude/janafThermoI.H at line 63.

FOAM aborting

#0  Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#1  Foam::error::abort() in "/opt/openfoam171/lib/linuxGccDPOpt/libOpenFOAM.so"
#2  Foam::specieThermo<Foam::janafThermo<Foam::perfectGas> >::H(double) const in "/opt/openfoam171/lib/linuxGccDPOpt/libreactionThermophysicalModels.so"
#3  Foam::ODEChemistryModel<Foam::psiChemistryModel, Foam::sutherlandTransport<Foam::specieThermo<Foam::janafThermo<Foam::perfectGas> > > >::solve(double, double) in "/opt/openfoam171/lib/linuxGccDPOpt/libchemistryModel.so"
#4  
 in "/opt/openfoam171/applications/bin/linuxGccDPOpt/reactingFoam"
#5  __libc_start_main in "/lib/tls/i686/cmov/libc.so.6"
#6  
 in "/opt/openfoam171/applications/bin/linuxGccDPOpt/reactingFoam"
Aborted

With my setup I wasn't able to get my Simulation go forward. Maybe someone has some marks or suggestions how I can get a stable ODE Solver for my reactinFoam simulation.

Thanks in advance.
pajofego

*********************************chemestryProperti es**********************************
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.7.1 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format binary;
class dictionary;
location "constant";
object chemistryProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

psiChemistryModel ODEChemistryModel<gasThermoPhysics>;

chemistry on;

chemistrySolver ode;
//chemistrySolver EulerImplicit;
//chemistrySolver sequential;

initialChemicalTimeStep 1e-07;

turbulentReaction on;

sequentialCoeffs
{
cTauChem 0.001;
equilibriumRateLimiter off;
}

EulerImplicitCoeffs
{
cTauChem 0.05;
equilibriumRateLimiter off;
}

odeCoeffs
{
ODESolver KRR4; //RK; //KRR4;
eps 0.05;
scale 1;
}

Cmix Cmix [ 0 0 0 0 0 0 0 ] 0.1;

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

[nakul]

Hi,

These error are coming because your solution begins to diverge. I don't think its a good idea to change the maximum number of integration steps without properly understanding its theoretical background.

Rather its better if you make changes in your test case and try to run it completely with SIBS and then see if you still get any error with KRR4.

You may check your BC as they are a major reason for causing the JANAF error you are getting with SIBS.

[conceptone]

Hi Nakul, I also meet the "too many integration step" problem, can you specify the possibility of the BC or is there any previous post discussing this?
Thanks

[conceptone]

Hi,pajofego
I confront this problem too, did you find the reason eventually?
Thanks