CFD Online Discussion Forums - one-way coupled particle tracking

Hi!

I am trying to do a particle tracking using one-way coupling. Searching the forum, I found this thread discussing the same thing: https://www.cfd-online.com/Forums/op...-tracking.html

In the thread, icoUncoupledKinematicParcelFoam is suggested as an appropriate solver. I tried to use the same method and obtained this result:

Attachment 99142

The figure shows the velocity magnitude of both the particle and 2-D flow. I applied a glyph filter over the particle track and made the radius scale with the velocity.

There are two problems:
1. I cannot specify the 3-dimensional initial position of the particle. I did specify 3 dimensions in constant -> kinematicCloudPositions, but only the x-value seems to have any effect.
2. The straight particle track suggests fully passive transport, because I varied the density and hoped to see vertical motion. (I tried running with rho0 values matching both g/cm3 and kg/m3, but it made no difference for vertical transport).

Since the particle is slowly accelerating in a somewhat uniform flow, I don't think it is a passive particle simulation as the description of the solver describes: https://www.openfoam.com/documentati...8C_source.html

So my current conclusion is that the particle is somehow modelled in 1 dimension only. I don't understand why this is the case.

I will include my kinematicCloudProperties file below, but I am not sure the error is in there. If anyone has a suggestion as to why my simulation behaves like this, or can direct me to other input files I should check, I will be very thankful :).

Code:

FoamFile

{

    version     2.0;

    format      ascii;

    class       dictionary;

    //location    "constant";

    object      kinematicCloudProperties;

}

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



solution

{

    active          true;

    coupled         false;

    transient       yes;

    cellValueSourceCorrection off;

    maxCo           0.3;



    interpolationSchemes

    {

        rho             cell;

        U               cellPoint;

        mu              cell;

    }



    integrationSchemes

    {

        U               Euler;

    }

}



constantProperties

{

    rho0            1500;

    youngsModulus   6e8;

    poissonsRatio   0.35;

}



subModels

{

    particleForces

    {

        sphereDrag;

        gravity;

    }



    injectionModels

    {

        model1

        {

            type            manualInjection;

            massTotal       0;

            parcelBasisType fixed;

            nParticle       1;

            SOI             0;

            positionsFile   "kinematicCloudPositions";

            U0              (0 0 0);

            sizeDistribution

            {

                type        fixedValue;

                fixedValueDistribution

                {

                    value   0.003;

                }

            }

        }

    }



    dispersionModel none;



    patchInteractionModel none;



    surfaceFilmModel none;



    stochasticCollisionModel none;



    collisionModel none;



    pairCollisionCoeffs

    {

        // Maximum possible particle diameter expected at any time

        maxInteractionDistance  0.0001;



        writeReferredParticleCloud no;



        pairModel pairSpringSliderDashpot;



        pairSpringSliderDashpotCoeffs

        {

            useEquivalentSize   no;

            alpha               0.12;

            b                   1.5;

            mu                  0.52;

            cohesionEnergyDensity 0;

            collisionResolutionSteps 12;

        };



        wallModel    wallLocalSpringSliderDashpot;



        wallLocalSpringSliderDashpotCoeffs

        {

            useEquivalentSize no;

            collisionResolutionSteps 12;

            upperWall

            {

                youngsModulus   1e10;

                poissonsRatio   0.23;

                alpha           0.12;

                b               1.5;

                mu              0.43;

                cohesionEnergyDensity 0;

            }

            lowerWall

            {

                youngsModulus   1e10;

                poissonsRatio   0.23;

                alpha           0.12;

                b               1.5;

                mu              0.43;

                cohesionEnergyDensity 0;

            }

            frontAndBack

            {

                youngsModulus   1e10;

                poissonsRatio   0.23;

                alpha           0.12;

                b               1.5;

                mu              0.1;

                cohesionEnergyDensity 0;

            }

        };

    }

}





cloudFunctions

{}