What makes the DPMFoam crashes for large particle every time?
 

I am doing the particle-gas simulation using the DPMFoam solver. I have run some cases successfully with small particle diameters. When I use the same model but a large particle diameter, the simulation will blow out every time.

Currently, I suspect that there is something wrong in the calculation for the large particle at the near-wall area (with very small CFD cells). See the attached picture, there is a singularity at the near-wall area, with a particle (the small white point) in it. Actually, the particle in the picture is much larger than its visualisation here, the particle diameter is 80um, while the minimum cells here are 5um for the near-wall area in wall-normal direction.

So, I would like to know if this situation (particle diameter larger than the cells) occurs to the crash in my simulation? If so, how can I fix it?

Also, I have tested the same large particles in a coarse mesh model, in which the minimum cells are larger than the particle size. It can run smoothly.

you solved this issue ? how to solve larger particle size > smaller cell size ?

As DPMFoam is based on the Lagrangian approach, where particle sizes are assumed to be point particles, it is not suitable for this kind of simulations. Your particles should always be much smaller than your cells.