Investigation of Shock-Induced Force Variations within a Random Distribution of Particles*

Particle-resolved inviscid simulations of a random bed of particles interacting with an underwater planar shock are performed to quantify the specific impact neighboring particles have on variations of drag and impulse. The simulations are governed by the Euler equations with a non-ideal stiffened-gas equation of state describing the water. Various Mach numbers and volume fraction scenarios were studied. Although the average drag on the particle bed is similar to the isolated particle case, significant variations in force on individual particles were observed. The specific arrangement of neighbors leads to variations in the peak drag force and the impulse shows that for the entire duration of the simulation particles can experience a consistent force due to the pressure fields induced by surrounding particles. Finally, it was determined that the lateral force on a particle is the same order of magnitude as the streamwise force on the particle. This research will aid future simulations understand the influence of neighboring particles, and isolated force models must be altered for a random distribution of particles.