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.