Multiphase particle-in-cell method

The multiphase particle-in-cell method (MP-PIC) is a numerical method for modeling particle-fluid and particle-particle interactions in a computational fluid dynamics (CFD) calculation. The MP-PIC method achieves greater stability than its particle-in-cell predecessor by simultaneously treating the solid particles as computational particles and as a continuum.

Source: Wikipedia — Multiphase particle-in-cell method (CC BY-SA 4.0)