[bijan darbari]

Dear Foamers

I was doing simulation of water laminar flow between two parallel plates and 100nm particles injected from a point in center of channel. DPMFoam solver used.

If I set "coupled true;" in kinematic cloud and set high value for "nParticle" ( for exmaple "nParticle 1e8;" ) the courant number increased and the solver diverged after some iteration.
But for low value of "nParticle" ( for example "nParticle 1e3;" ) the solution was done without any problem.

The case file attached.
Best regards
Bijan Darbari

The error:

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  dev                                   |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : dev-46d69e1deaed
Exec   : DPMFoam
Date   : Jul 30 2016
Time   : 02:59:11
Host   : "bijan-virtual-machine"
PID    : 9318
Case   : /home/bijan/Desktop/mycase11
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0


PIMPLE: Operating solver in PISO mode


Reading g
Reading field U

Reading field p

Reading/calculating continuous-phase face flux field phic

Creating turbulence model

Selecting incompressible transport model Newtonian
Creating field alphac

Constructing kinematicCloud kinematicCloud
Constructing particle forces
    Selecting particle force sphereDrag
Constructing cloud functions
    none
Constructing particle injection models
Creating injector: model1
Selecting injection model kinematicLookupTableInjection
    Constructing 2-D injection
    Choosing nParticle to be a fixed value, massTotal variable now does not determine anything.
Selecting dispersion model none
Selecting patch interaction model localInteraction
    Interaction fields will not be written
Selecting stochastic collision model none
Selecting surface film model none
Selecting U integration scheme Euler
Selecting collision model none
Selecting turbulence model type laminar

Starting time loop

Courant Number mean: 0.019975 max: 0.02
Time = 0.0001

Evolving kinematicCloud

Solving 2-D cloud kinematicCloud

Cloud: kinematicCloud injector: model1
    Added 2 new parcels

Cloud: kinematicCloud
    Current number of parcels       = 2
    Current mass in system          = 3.14159e-10
    Linear momentum                 = (3.80393e-11 0 0)
   |Linear momentum|                = 3.80393e-11
    Linear kinetic energy           = 3.33858e-06
    model1:
        number of parcels added     = 2
        mass introduced             = 3.14159e-10
    Parcel fate (number, mass)      : patch frontAndBack
      - escape                      = 0, 0
      - stick                       = 0, 0
    Parcel fate (number, mass)      : patch top
      - escape                      = 0, 0
      - stick                       = 0, 0
    Parcel fate (number, mass)      : patch bottom
      - escape                      = 0, 0
      - stick                       = 0, 0
    Parcel fate (number, mass)      : patch inlet
      - escape                      = 0, 0
      - stick                       = 0, 0
    Parcel fate (number, mass)      : patch outlet
      - escape                      = 0, 0
      - stick                       = 0, 0
    Rotational kinetic energy       = 0

PIMPLE: iteration 1
smoothSolver:  Solving for U.airx, Initial residual = 1, Final residual = 1.84189e-09, No Iterations 2
smoothSolver:  Solving for U.airy, Initial residual = 0.0405478, Final residual = 9.99002e-07, No Iterations 1
GAMG:  Solving for p, Initial residual = 1, Final residual = 0.00399794, No Iterations 5
time step continuity errors : sum local = 0.138311, global = -0.000639183, cumulative = -0.000639183
GAMG:  Solving for p, Initial residual = 0.00962409, Final residual = 6.10127e-07, No Iterations 11
time step continuity errors : sum local = 5.79705e-05, global = -1.30051e-06, cumulative = -0.000640483
ExecutionTime = 0.38 s  ClockTime = 0 s

Courant Number mean: 198.274 max: 202140
Time = 0.0002

Evolving kinematicCloud

Solving 2-D cloud kinematicCloud

Cloud: kinematicCloud injector: model1
    Added 2 new parcels

#0  Foam::error::printStack(Foam::Ostream&) at ??:?
#1  Foam::sigFpe::sigHandler(int) at ??:?
#2  ? in "/lib/x86_64-linux-gnu/libc.so.6"
#3  ? at ??:?
#4  ? at ??:?
#5  ? at ??:?
#6  ? at ??:?
#7  ? at ??:?
#8  ? at ??:?
#9  ? at ??:?
#10  ? at ??:?
#11  ? at ??:?
#12  ? at ??:?
#13  __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#14  ? at ??:?
Floating point exception (core dumped)

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

solution
{
    active          true;
    coupled         true;
    transient       yes;
    cellValueSourceCorrection on;


    interpolationSchemes
    {
        rho.air         cell;
        U.air           cell;
        mu.air          cell;
    }

    averagingMethod basic;

    integrationSchemes
    {
        U               Euler;
    }

    sourceTerms
    {
        schemes
        {
            U explicit 0.1;
        }
    }
}

constantProperties
{
    rho0            10;

    alphaMax        0.05;
}

subModels
{
    particleForces
    {
        sphereDrag;
        
    }

    injectionModels
    {
        /*
            % matlab/octave calculation of flow rate
            alpha=0.1
            U=20
            A=0.01^2
            Q=U*A
            d=650e-6
            v=(4/3)*pi*(d/2)^3
            n=1
            rate=alpha*Q/(v*n)
        */

        
        model1
        {
            type            kinematicLookupTableInjection;
            parcelBasisType fixed;
            inputFile       "parcelInjectionProperties";
            nParticle       1e8;
            parcelsPerSecond 20000;
            massTotal  3.14e7;
            SOI 0;
            duration 150;
            randomise       false;
        }

    }

    dispersionModel none;

    patchInteractionModel localInteraction;

    localInteractionCoeffs
    {
        patches
        (
            frontAndBack
            {
                type rebound;
                e    1;
                mu   0;
            }

           top
            {
                type stick;
                 e    1;
                mu   0;
    
            }

            bottom
            {
                type stick;
                 e    1;
                mu   0;
              
            }
            
            inlet
            {
                type escape;
            }

            outlet
            {
                type escape;
            }
        );
    }

    heatTransferModel none;

    surfaceFilmModel none;

    packingModel none;

    dampingModel none;
    collisionModel  none;


    isotropyModel none;

    
    stochasticCollisionModel none;

    radiation off;
}


cloudFunctions
{}


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

FVschemes:

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

ddtSchemes
{
    default Euler;
}

gradSchemes
{
    default         Gauss linear;
}

divSchemes
{
    default         none;

    div(alphaPhic,U.air)    Gauss linearUpwindV unlimited;
    div(((alpha.air*nuEff.air)*dev2(T(grad(U.air))))) Gauss linear;
}

laplacianSchemes
{
    default         Gauss linear corrected;
}

interpolationSchemes
{
    default         linear;
}

snGradSchemes
{
    default         corrected;
}

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

FVsolution:

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

solvers
{
    p
    {
        solver          GAMG;
        tolerance       1e-06;
        relTol          0.01;
        smoother        GaussSeidel;
    }

    pFinal
    {
        solver          GAMG;
        tolerance       1e-06;
        relTol          0;
        smoother        GaussSeidel;
    }

    "(U|k|omega).*"
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-05;
        relTol          0.1;
    }

    "(U|k|omega).*Final"
    {
        $U;
        tolerance       1e-05;
        relTol          0;
    }
}

PIMPLE
{
    nOuterCorrectors 1;
    nCorrectors     2;
    momentumPredictor yes;
    nNonOrthogonalCorrectors 0;
    pRefCell        0;
    pRefValue       0;
}

relaxationFactors
{
}


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