[srimantamaity96@gmail.com]

Dear All,

I am currently working on simulating gas filling in a capillary gas cell. The geometry of the gas cell is shown in the attached figure. It features two inlets through which helium gas is introduced, driven by a fixed inlet pressure of 4000 Pa. Along the axis of the capillary tube, there are two outlets maintained at a constant pressure of 1 Pa.

I am using OpenFOAM v12 with the fluid solver for a compressible, turbulent flow under steady-state conditions.

The simulation converged successfully when I modeled the front and back walls as empty - effectively a 2D configuration. However, when I extended the model to 3D by setting the front and back walls to type wall (and updated the relevant boundary conditions for p, U, T, epsilon, k, etc.), the simulation terminated with the error:

"Floating point exception (core dumped)"
after only a few iterations.

I would greatly appreciate any suggestions or insights you might have to resolve this issue.

The details of the output log file, p/U files, and fvSolution, fvSchemes are given below.

Best regards,
Srimanta


Time = 3s

smoothSolver: Solving for Ux, Initial residual = 0.449802, Final residual = 0.0373715, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 0.207146, Final residual = 0.0160427, No Iterations 2
smoothSolver: Solving for Uz, Initial residual = 0.44778, Final residual = 0.0363282, No Iterations 2
smoothSolver: Solving for h, Initial residual = 0.0317376, Final residual = 0.0016145, No Iterations 2
GAMG: Solving for p, Initial residual = 0.708277, Final residual = 0.0351155, No Iterations 26
time step continuity errors : sum local = 0.691129, global = -0.0797781
GAMG: Solving for p, Initial residual = 0.366553, Final residual = 0.0181471, No Iterations 28
time step continuity errors : sum local = 0.405866, global = -0.0558136, cumulative = -0.13899
smoothSolver: Solving for epsilon, Initial residual = 0.575394, Final residual = 3.63079e-09, No Iterations 1
smoothSolver: Solving for k, Initial residual = 0.0915262, Final residual = 3.98163e-05, No Iterations 1
ExecutionTime = 168.073 s ClockTime = 169 s

Time = 4s

smoothSolver: Solving for Ux, Initial residual = 0.111691, Final residual = 0.00918139, No Iterations 2
smoothSolver: Solving for Uy, Initial residual = 0.259757, Final residual = 0.0203449, No Iterations 2
smoothSolver: Solving for Uz, Initial residual = 0.308091, Final residual = 0.0250928, No Iterations 2
smoothSolver: Solving for h, Initial residual = 0.0761183, Final residual = 0.00352772, No Iterations 2
#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 ? in "/usr/lib/x86_64-linux-gnu/libc.so.6"
#3 Foam::GAMGSolver::scale(Foam::Field<double>&, Foam::Field<double>&, Foam::lduMatrix const&, Foam::FieldField<Foam::Field, double> const&, Foam::UPtrList<Foam::lduInterfaceField const> const&, Foam::Field<double> const&, unsigned char) const at ??:?
#4 Foam::GAMGSolver::Vcycle(Foam::PtrList<Foam::lduMa trix::smoother> const&, Foam::Field<double>&, Foam::Field<double> const&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::Field<double>&, Foam::PtrList<Foam::Field<double> >&, Foam::PtrList<Foam::Field<double> >&, unsigned char) const at ??:?
#5 Foam::GAMGSolver::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
#6 Foam::fvMatrix<double>::solveSegregated(Foam::dict ionary const&) at ??:?
#7 Foam::fvMatrix<double>::solve(Foam::dictionary const&) at ??:?
#8 Foam::fvMatrix<double>::solve() at ??:?
#9 Foam::solvers::isothermalFluid::correctPressure() at ??:?
#10 Foam::solvers::isothermalFluid:ressureCorrector( ) at ??:?
#11 ? in "/opt/openfoam12/platforms/linux64GccDPInt32Opt/bin/foamRun"
#12 ? in "/usr/lib/x86_64-linux-gnu/libc.so.6"
#13 __libc_start_main in "/usr/lib/x86_64-linux-gnu/libc.so.6"
#14 ? in "/opt/openfoam12/platforms/linux64GccDPInt32Opt/bin/foamRun"
Floating point exception (core dumped)




/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 12
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [1 -1 -2 0 0 0 0];

internalField uniform 1;

boundaryField
{
inlet
{
type totalPressure;
p0 uniform 4000;
gamma 1.66;
}
outlet
{
type fixedValue;
value uniform 1;
}
upperWall
{
type zeroGradient;
}
lowerWall
{
type zeroGradient;
}
sideWall
{
type zeroGradient;
}
frontAndBack
{
type zeroGradient;
}
}

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

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 12
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
inlet
{
type pressureInletVelocity;
value uniform (0 10 0); // initial guess
}

outlet
{
type pressureInletOutletVelocity;
value uniform (0 0 0);
}

upperWall
{
type noSlip;
}

lowerWall
{
type noSlip;
}

sideWall
{
type noSlip;
}

frontAndBack
{
type noSlip;
}

}

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

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 12
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "system";
object fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
default steadyState;
}

gradSchemes
{
default Gauss linear;

limited cellLimited Gauss linear 1;
}

divSchemes
{
default none;

div(phi,U) bounded Gauss linearUpwindV limited;

div(phi,h) bounded Gauss linearUpwind limited;
div(phi,K) bounded Gauss linearUpwind limited;

div(phi,epsilon) bounded Gauss linearUpwind limited;
div(phi,k) bounded Gauss linearUpwind limited;

div(((rho*nuEff)*dev2(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
default Gauss linear corrected;
}

interpolationSchemes
{
default linear;
}

snGradSchemes
{
default corrected;
}

wallDist
{
method meshWave;
}
// ************************************************** *********************** //

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 12
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
format ascii;
class dictionary;
location "system";
object fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{

"rho.*"
{
solver diagonal;
}

p
{
solver GAMG;
smoother GaussSeidel;

tolerance 1e-7;
relTol 0.05;
}

"(U|h|k|epsilon)"
{
solver smoothSolver;
smoother symGaussSeidel;

tolerance 1e-8;
relTol 0.1;
}
}

PIMPLE
{
nNonOrthogonalCorrectors 0;
nOuterCorrectors 1;
nCorrectors 2;

transonic no;
consistent no;

residualControl
{
p 1e-4;
U 1e-4;
"(k|omega|epsilon|h)" 1e-3;
}
}

relaxationFactors
{
fields
{
p 0.3;
}

equations
{
U 0.7;
h 0.7;
k 0.7;
epsilon 0.7;
}
}

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