[Trollstoi]

Hello everyone,

I wasn't able to find information about the parameters entered in general in sizeDistribution. I don't know what exactly the inputs are. I was able to find some examples of generalDistribution(see below), however these don't enlighten me. I already know that the first column is diameter and the second column is a probability which does not need to be normalized. However, which probability to enter here I don't know. Can anyone help?

Might the input be

xi q3(xi)

or

xi q3(xi)*∆xi

?

q3(xi) here is of dimension 1/µm

/*--------------------------------*- 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       dictionary;
    location    "constant";
    object      particleProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

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

    integrationSchemes
    {
        U               Euler;
    }

    sourceTerms
    {
        schemes
        {
            U semiImplicit 1;
        }
    }
}

constantProperties
{
    parcelTypeId 1;

    rhoMin          1e-15;
    minParcelMass   1e-15;

    rho0            2526;
    youngsModulus   1e8;
    poissonsRatio   0.35;

    constantVolume  false;

    alphaMax        0.99;
}

subModels
{
    particleForces
    {
        ErgunWenYuDrag
        {
            alphac alpha.air;
        }
        gravity;
    }


    injectionModels
    {
        model1
        {
            type            patchInjection;
            massTotal       0;
            parcelBasisType fixed;
            nParticle       1;
            SOI             0;
            parcelsPerSecond    100;
        duration        1;
        patchName        INLET;
            U0              (0 30 0);
        flowRateProfile constant 1;
            sizeDistribution
            {
                type        general;
                generalDistribution
                {
                
                    distribution
                    (
                        (05e-05        5.19202)
                        (10e-05        33.91157)
                        (15e-05        24.78618)
                        (20e-05        14.25689)
                        (25e-05        8.68968)
                        (30e-05        5.07100)
                        (35e-05        3.130547)
                        (40e-05        1.795223)
                        (45e-05        1.1497498)
                        (50e-05        0.6737130)
                        (55e-05        0.5002420)
                        (60e-05        0.2944973)
                        (65e-05        0.1855736)
                        (70e-05        0.10085525)
                        (75e-05        0.1129578828)
                        (80e-05        0.0726157818)

                    );
                
                }
            }
        }
    }

    dispersionModel none;

    patchInteractionModel localInteraction;

    localInteractionCoeffs
    {
        patches
        (
            INLET
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            OUTLET
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            AUSSLASSROHR
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            AUSSLASSGLOCKE
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            EINLASSROHR
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            MESSKAMMER
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            DUESE_INNEN
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            DUESE_STIRNFLAECHE
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
            DUESE_AUSSEN
            {
                type rebound;
                e    0.97;
                mu   0.09;
            }
        );
    }

    StandardWallInteractionCoeffs
    {
        type rebound;
        e    0.97;
        mu   0.09;
    }

    heatTransferModel none;

    surfaceFilmModel none;

    collisionModel pairCollision;

    pairCollisionCoeffs
    {
        maxInteractionDistance  0.0025;

        writeReferredParticleCloud no;

        pairModel pairSpringSliderDashpot;

        pairSpringSliderDashpotCoeffs
        {
            useEquivalentSize   no;
            alpha               0.02;
            b                   1.5;
            mu                  0.10;
            cohesionEnergyDensity 0;
            collisionResolutionSteps 12;
        };

        wallModel wallSpringSliderDashpot;

        wallSpringSliderDashpotCoeffs
        {
            useEquivalentSize no;
            collisionResolutionSteps 12;
            youngsModulus   1e8;
            poissonsRatio   0.23;
            alpha           0.01;
            b               1.5;
            mu              0.09;
            cohesionEnergyDensity 0;
        };

        UName U.air;
    }

    stochasticCollisionModel none;

    radiation off;
}


cloudFunctions
{}


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

[Trollstoi]

As I understand the final formula of the equation in general.c results in:

y_n+1 - y_n = 0,5 * (x_n+1 - x_n) * (q_3(x_n+1) + q_3(x_n))

So the general distribution is valid for inputs of a particle size distribution of "equally sized sieves" (means ∆x = const. for all inputs) which you usually don't get from experiments. I converted my distribution via a preprocessor to a uniform-sievesize now.
the dimension of q3 is also of no importance in this case because all "sieves" are equal in size and therefore q3 and q3*∆x will yield the same result.