Analysis of Compressible Particle-Particle Interaction in Ejecta Particle Simulations

Ejecta physics play an important role in materials shocked by high explosives. When a shock impacts a surface of a solid material and melts it, the Richtmyer-Meshkov instability grows perturbations on the surface until particles are ejected. After release, the ejecta travel through the post-shock compressible flow. To simulate the large number of ejecta particles, an Euler-Lagrange approach is preferred to model the physics at a subgrid-scale level. If the volume fraction of the particles is high enough, one needs to resolve the particle-particle interaction. In this talk, we review efforts to model such systems, bring different force components of particle hydrodynamics to attention, and examine the relative importance of each term.