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floating point exception - epsilon bounds

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Old   May 3, 2016, 17:36
Default floating point exception - epsilon bounds
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Vinícius da Costa Ávila
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Hi,

I am running a case with twoPhaseEulerFoam (of30x) and it is diverging, the turbulence parameters bounds are exploding. I am running with mixtureKEpsilon

I have a mass source (1e-3 kg/s) for air. I have 750k cells on my mesh, approximately.
My checkMesh returns Mesh OK, I really don’t think the mesh is the problem.

I have attached my case files.

Here are the last lines of my logfile:

Code:
Courant Number mean: 8.188e-06 max: 0.361754
Max Ur Courant Number = 0.459206
deltaT = 2.1298e-42
Time = 7.07349

PIMPLE: iteration 1
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.0565778  Min(alpha.air) = -0.00807788  Max(alpha.air) = 1
Constructing face momentum equations
smoothSolver:  Solving for e.air, Initial residual = 1, Final residual = 1, No Iterations 0
smoothSolver:  Solving for e.water, Initial residual = 1, Final residual = 1, No Iterations 0
min T.air 293
min T.water 292.979
GAMG:  Solving for p_rgh, Initial residual = 0.33279, Final residual = 6.33525e-21, No Iterations 1
GAMG:  Solving for p_rgh, Initial residual = 3.86492e-23, Final residual = 3.86492e-23, No Iterations 0
PIMPLE: iteration 2
MULES: Solving for alpha.air
MULES: Solving for alpha.air
alpha.air volume fraction = 0.0565752  Min(alpha.air) = -0.0298379  Max(alpha.air) = 1.0266
Constructing face momentum equations
smoothSolver:  Solving for e.air, Initial residual = 1, Final residual = 1, No Iterations 0
smoothSolver:  Solving for e.water, Initial residual = 1, Final residual = 1, No Iterations 0
min T.air 293
min T.water 292.979
GAMG:  Solving for p_rgh, Initial residual = 0.0360245, Final residual = 1.12064e-19, No Iterations 1
GAMG:  Solving for p_rgh, Initial residual = 3.59528e-21, Final residual = 3.59528e-21, No Iterations 0
bounding km, min: -2628.02 max: 6.0619e+46 average: 9.90038e+40
bounding epsilonm, min: -6.60646e+118 max: 7.6561e+117 average: 5.28961e+112
smoothSolver:  Solving for epsilonm, Initial residual = 0.38965, Final residual = 2.44749e-21, No Iterations 1
bounding epsilonm, min: -5.4597e+115 max: 5.56411e+117 average: 1.23861e+113
smoothSolver:  Solving for km, Initial residual = 1.02552e-56, Final residual = 1.02552e-56, No Iterations 0
[1] #0  Foam::error::printStack(Foam::Ostream&) at ??:?
[1] #1  Foam::sigFpe::sigHandler(int) at ??:?
[1] #2  ? in "/lib64/libc.so.6"
[1] #3  Foam::nutkWallFunctionFvPatchScalarField::calcNut() const at ??:?
[1] #4  Foam::nutWallFunctionFvPatchScalarField::updateCoeffs() at ??:?
[1] #5  Foam::fvPatchField<double>::evaluate(Foam::UPstream::commsTypes) at ??:?
[1] #6  Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::GeometricBoundaryField::evaluate() at ??:?
[1] #7  Foam::RASModels::mixtureKEpsilon<Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Foam::PhaseCompressibleTurbulenceModel<Foam::phaseModel> > > >::correctNut() at ??:?
[1] #8  Foam::RASModels::mixtureKEpsilon<Foam::EddyDiffusivity<Foam::ThermalDiffusivity<Foam::PhaseCompressibleTurbulenceModel<Foam::phaseModel> > > >::correct() at ??:?
[1] #9  Foam::twoPhaseSystem::correctTurbulence() at ??:?
Does anyone have any suggestion? It'd be REALLY appreciated.
Attached Files
File Type: zip case.zip (24.1 KB, 8 views)
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Old   May 26, 2016, 16:13
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Hi

I use your solver,and I have this problem too
Do you solve it?

Best Regards
Masoud
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Old   May 26, 2016, 16:34
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Hi, I think increasing pimple outer loops solved it for me.
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Old   May 26, 2016, 17:20
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Quote:
Originally Posted by avila.vc View Post
Hi, I think increasing pimple outer loops solved it for me.
Hi

thank u for your suggestion
can i see your case?
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Old   July 1, 2016, 10:54
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I am facing the same problems with twoPhaseEulerFoam coupled with mixtureKEpsilon. Only the epsilonm equation after some iteration starts to become unbounded and negative minimum values start to occur. I do not think that it is due to nOuterCorrection since now I have 3 nOuterCorrection.

Thanks for any suggestion
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