# Particles

MFIX-Exa supports solid particles which are immersed in the fluid. In the future particles can be implemented using the immersed-boundary method (and hence these IBM-particles can support non-spherical shapes, and special hydrodynamical and chemical interactions). But for now, particles are spherical, with approximate fluid-particle interactions. The main consequence of this approximation is that particles should not be bigger than the fluid grid resolution.

Particles interact with container walls (implemented using AMReX’s Embedded-Boundary functionality) using a level-set constructed from the signed closest distance function at the beginning of the simulation.

Refer to the subsequent sections for details on the implementation of the particle-particle, particle-fluid, and particle-wall interactions.

Contents:

- Particle Basics
  - Particle Dynamics
- Particle/Fluid Interactions
- Particle/Wall Interactions
- Particles on GPUs