Thank you for the ideas and the suggestions


I am happy to update you that I can activate an interaction (coupling) between MPM and the fluid phase.


As you remember, I had a problem with the MPM particle and fluid phase do not interact with each other (picture below).

I used a mixture model as a multiphase, the primary phase is air and the second phase is water. I let an MPM particle settle down by gravity into water.


Now, I can activate a coupling between MPM and multiphase (picture below).


Just only one thing it was strange.

If you notice the above picture carefully, the volume fraction of the particle did not recognize in a primary phase (in my case, it is air). 

I've tried to fix it but I've not found a way to handle it.

Do you have any general suggestions to fix it?