[Turhan]

Hello all,

I am adding particles to my system, which consists of flowing water and sand, and in order to improve the execution time I would like to make use of parcels that contain multiple particles.
Now I am familiar with its general principle, particles with similar density, size and shape are considered as 1 entity, and only 1 calculation is done for them.

However, I would like to understand how OpenFoam exactly does this and I couldn't tell when I looked at their website. The reason I want to know this is because a higher amount of parcel seems to affect the flow exponentially stronger and even cause errors. (I do 4 way coupling)
In order to fix this I first want to understand how a parcel is simulated.

Also, when I add a single parcel that consists of multiple particles I only see 1 particle in paraView. Does this mean openfoam adds 1 parcel with the mass of multiple particles?

Could someone explain how parcels are simulated, or tell me where I could figure this out?
Or possibly tell me what actions I can take to make the flow more stable when increasing the particles in a parcel? Cause I changed the timestep and mesh size but that did not affect it.