[chemcfd]

Hi, I am trying to run a case in compressibleInterFoam using the following boundary conditions but I face the following error: "Maximum number of iterations exceeded".

Total run time is 1000 s but it crashes at 0.8 s. I guess there is a problem with the boundary conditions. I greatly appreciate your suggestions to correct my boundary conditions.

I need to add that I try to set constant velocity at the inlet and no slip at the walls (grains). Operating pressure is 4.6e5 Pa at constant temperature of 300 K. Fluids are air and water.



U: constant velocity

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField uniform (0 0 0);


boundaryField
{
inlet
{
type fixedValue;
value uniform (-5e-5 0 0);
}
outlet
{
type zeroGradient;
}
grains
{
type fixedValue;
value uniform (0 0 0);
}
frontAndBackPlanes
{
type empty;
}
}

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





alpha.water:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object alpha.water;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField
{
grains
{
type constantAlphaContactAngle;
theta0 45;
limit gradient;
value uniform 0;
}

inlet
{
type fixedValue;
value uniform 0;
}

outlet
{
type zeroGradient;
}

frontAndBackPlanes
{
type empty;
}
}

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




p:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField uniform 4.5e6;


boundaryField
{
grains
{
type zeroGradient;
}

inlet
{
type zeroGradient;
}

outlet
{
type fixedValue;
value uniform 4.5e6;
}

frontAndBackPlanes
{
type empty;
}

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




p_rgh:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField uniform 4.5e6;


boundaryField
{
grains
{
type zeroGradient;
}

inlet
{
type zeroGradient;
}

outlet
{
type fixedValue;
value uniform 4.5e6;
}

frontAndBackPlanes
{
type empty;
}
}

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




T:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 1 0 0 0];

internalField uniform 300;

boundaryField
{
grains
{
type zeroGradient;
}

inlet
{
type fixedValue;
value uniform 300;
}

outlet
{
type zeroGradient;
}

frontAndBackPlanes
{
type empty;
}
}

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

[TobM]

It seems you have a 2D case. Please compare your settings with one of the tutorials for compressibleInterFoam, like damBreak tutorial.
See where they differ and change your case files accordingly.

Post the files please in code tags, makes it more easily to read.

Output of checkMesh and the log file, at least the last few iterations/time steps would be useful.

[SmokedJuggler]

Hello everyone,

I am using CompressibleInterFoam for a test case of a rectangular computational domain. I have two walls on the left boundary and an Inlet in the middle. Top and Bottom Patches are free surfaces. And the Right patch is outlet. And as a test case I initialize all the regions to be air.


The temperature decreases rapidly but does not become negative anymore. However, I am getting the following error:

Courant Number mean: 0.017525563 max: 0.36055112
deltaT = 3.1316128e-05
Time = 0.01149259369

PIMPLE: iteration 1
MULES: Solving for alpha.water
Liquid phase volume fraction = 0.99838497  Min(alpha.water) = 0  Min(alpha.air) = -6.1014024e-05
diagonal:  Solving for rho, Initial residual = 0, Final residual = 0, No Iterations 0
smoothSolver:  Solving for T, Initial residual = 0.0020526023, Final residual = 0.0023329173, No Iterations 1000
min(T) 0.93072415
GAMG:  Solving for p_rgh, Initial residual = 0.17359627, Final residual = 6.6372495e-05, No Iterations 1
max(U) 34.502714
min(p_rgh) 52859.589
#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3  Foam::PCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
#4  Foam::fvMatrix<double>::solveSegregated(Foam::dictionary const&) at ??:?
#5  Foam::fvMatrix<double>::solve(Foam::dictionary const&) at ??:?
#6  ? at ??:?
#7  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#8  ? at ??:?
Floating point exception (core dumped)

My B.C are:

alpha.water

    object      alpha.water;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    FrontAndBack
    {
        type            empty;
    }
    Inlet
    {
        type            zeroGradient;
    }
    Outlet
    {
        type            zeroGradient;
    }
    TopAndBottomPatches
    {
        type            inletOutlet;
        inletValue      uniform 0;
        value           uniform 0;
    }
    Walls
    {
        type            zeroGradient;
    }
}

U:

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

internalField   uniform (0 0 0);

boundaryField
{
    FrontAndBack
    {
        type            empty;        
    }
    Inlet
    {
        type            fixedValue;
        value           uniform (10 0 0);
    }
    Outlet
    {
        type            zeroGradient;
    }
    TopAndBottomPatches
    {
        type            pressureInletOutletVelocity;
        value           uniform (0 0 0);
    }
    Walls
    {
        type            noSlip;
    }

p:

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

internalField   uniform 1e5;

boundaryField
{
    FrontAndBack
    {
        type            empty;
    }
    Inlet
    {
        type            zeroGradient;
    }
    Outlet
    {
        type            fixedValue;
        value           uniform 1e5;

    }
    TopAndBottomPatches
    {
        type            totalPressure;
        p0              uniform 1e5;
    }
    Walls
    {
        type            zeroGradient;
    }
}

p_rgh

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

internalField   uniform 1e5;

boundaryField
{
    FrontAndBack
    {
        type            empty;
    }
    Inlet
    {
        type            zeroGradient;
    }
    Outlet
    {
        type            fixedValue;
        value           uniform 1e5;
    }
    TopAndBottomPatches
    {
        type            totalPressure;
        p0              uniform 1e5;
    }
    Walls
    {
        type            fixedFluxPressure;
        value           uniform 0;
 
    }
}

T

dimensions      [0 0 0 1 0 0 0];

internalField   uniform 300;

boundaryField
{
    FrontAndBack
    {
        type            empty;
    }
    Inlet
    {
        type            fixedValue;
        value           uniform 300; 
    }
    Outlet
    {
        type            zeroGradient;
    }
    TopAndBottomPatches
    {
        type            zeroGradient;
    }
    Walls
    {
        type            zeroGradient;
    }
}

I would appreciate if someone could give me some guidance on how to resolve the issue and help me understand why this error is happening.

Thanks to all,

[TobM]

p is calculated from p_rgh so p has to be type calculated everywhere as in the tutorial cases.
When you use compressibleInterFoam it makes no sense just to simulate air. At least a little bit of alpha.water somewhere in your domain would help.