[evamaria]

Dear foamers,


I have encountered a strange behaviour with MPPICFoam. I set up a case, to fill a 2D column with lagranigan particles. When the cellValueSourceCorrection is set to off, particles suddenly vanish when the bed is packing.


The particles, are not escaping through a patch.



Does somebody know, how and why particles are removed / deleted?


I attached the two case setups - everything was run in OpenFOAM 8.

[GerhardHolzinger]

Hi,

I have no idea what causes the particle loss, however, the particles are not lost when you change the interpolation scheme for velocity to cellPointWallModified. This scheme was removed by commit fbf0020, and reinstated by commit 63b641a.

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

[evamaria]

Hi,

thanks a lot!


Do you think this should be reported as a bug? In my opinion, it is clearly unwanted and unphysical behaviour.

I am wondering, if this also happens for other simulations, where you might not notice it that easily.

[erice]

Hi,

I met the same problem for cellValueSourceCorrection off as the turtorials. Do you know what cellValueSourceCorrection means? And if set cellValueSourceCorrection to on do some help to the problem?

[evamaria]

Hi,



cellValueSourceCorrection updates the carrier velocity and temperature according to the latest transfer information in https://cpp.openfoam.org/v9/ThermoParcel_8C_source.html .



As mentioned in the reply by Gerhard, if you change your U interpolation scheme the problem should be fixed. However, I am not sure why it does not work otherwise / where the particles get "lost".



Best regards,

Eva

[erice]

Hi,
It seems doesn't work for me. I change the interpolation scheme of U to cellPointWallModified, but the particle still get lost. Do you know is there any other reason? Could it be possible connected with my sliding mesh?

[evamaria]

Can you provide a minimal working example or more details on your setup (e.g. OF, version, particle dict)?

[erice]

Sure,
Version: Openfoam10,
Based on InterFoam I coupled the kinematicCloud into the solver.
storeGlobalposition is added.
Sliding Mesh is used to rotate.
particle dict is as your suggestion(CellPointWallModified for U)
Sorry I cannot post an example, I will provide any information if you need and hope you can provide some suggestion.

[evamaria]

I am sorry, I don't think I can help you without a sample case.



Did you check, if particles get lost over patches? With rotating mesh there are many more possibilities, where a problem could occur with the particles.



Try to simplify the case and see if the problem still occurs there.