[cojua8]

Hello,

I'm working with the intermediate library, trying to use patchInteractionModel and collisionModel, so that particle-particle interaction has a soft sphere treatment (pairSpringSliderDashpot), and the particle-wall interaction has a stick condition.
This way, the expected behavior is that the floor is filled with particles and the moving ones bounce on them.

It seems like the wallSpringSliderDashpot model overrides the stick condition, and the particles just keep bouncing.
Also, there is no 'none' wall model.

    
standardWallInteractionCoeffs
{
        type        stick; // stick, escape
        e           1;       // optional - elasticity coeff
        mu          0;       // optional - restitution coeff
}

    collisionModel pairCollision;

    pairCollisionCoeffs
    {
        maxInteractionDistance  0.00069;

        writeReferredParticleCloud no;

        pairModel pairSpringSliderDashpot;

        pairSpringSliderDashpotCoeffs
        {
                                  // alpha =0.30 para e=0.65
            alpha           0.3; //relacionado empiricamente con coef. de rest.
            b               1.5;  //1 para 2D, 1.5 para 3D
            mu              0.1; // coeficiente de friccion
            cohesionEnergyDensity 0;
            collisionResolutionSteps 12;
            useEquivalentSize   no;
        };

        wallModel wallSpringSliderDashpot;

        wallSpringSliderDashpotCoeffs
        {
                                  // alpha =0.30 para e=0.65
            alpha           5.0; //relacionado empiricamente con coef. de rest.
            b               1.0; //1 para 2D, 1.5 para 3D
            mu              0.1; // coeficiente de friccion
            youngsModulus   1e10;
            poissonsRatio   0.23;
            cohesionEnergyDensity 0;
            collisionResolutionSteps 12;
            useEquivalentSize no;
        };
    }

[saeedja]

Hi,

Did you find any answer to this question? I have a similar problem

[JoeGoe]

Originally Posted by cojua8

Hello,

I'm working with the intermediate library, trying to use patchInteractionModel and collisionModel, so that particle-particle interaction has a soft sphere treatment (pairSpringSliderDashpot), and the particle-wall interaction has a stick condition.
This way, the expected behavior is that the floor is filled with particles and the moving ones bounce on them.

It seems like the wallSpringSliderDashpot model overrides the stick condition, and the particles just keep bouncing.
Also, there is no 'none' wall model.

    
standardWallInteractionCoeffs
{
        type        stick; // stick, escape
        e           1;       // optional - elasticity coeff
        mu          0;       // optional - restitution coeff
}

    collisionModel pairCollision;

    pairCollisionCoeffs
    {
        maxInteractionDistance  0.00069;

        writeReferredParticleCloud no;

        pairModel pairSpringSliderDashpot;

        pairSpringSliderDashpotCoeffs
        {
                                  // alpha =0.30 para e=0.65
            alpha           0.3; //relacionado empiricamente con coef. de rest.
            b               1.5;  //1 para 2D, 1.5 para 3D
            mu              0.1; // coeficiente de friccion
            cohesionEnergyDensity 0;
            collisionResolutionSteps 12;
            useEquivalentSize   no;
        };

        wallModel wallSpringSliderDashpot;

        wallSpringSliderDashpotCoeffs
        {
                                  // alpha =0.30 para e=0.65
            alpha           5.0; //relacionado empiricamente con coef. de rest.
            b               1.0; //1 para 2D, 1.5 para 3D
            mu              0.1; // coeficiente de friccion
            youngsModulus   1e10;
            poissonsRatio   0.23;
            cohesionEnergyDensity 0;
            collisionResolutionSteps 12;
            useEquivalentSize no;
        };
    }

Hi,


even though your post is old, I might just share my findings on that issue.


I ran into the same problem, where the patchInteraction-Model (in my case: escape) was overwritten by the wallSlingSliderDashpot model and the particles simply wouldn't leave my domain. Using two-way coupling, the particles did leave the output as planned.



The identification of the problem took me quite some time, but the solution is rather simple: The patch interaction model does only work for patches. If your patch is in constant/boundary difned as a wall, it will be assigned a particle-wall collision when using four way coupling. Since it has overwritten "type: escape" in my case, I guess it will do the same for "type: stick" as in your simulation.


Maybe this was/will be helpful to somebody.


Cheers Joe