Adaptive mesh axi-symmetric simulation of droplet impact with a spherical particle in mid-air

In this study, droplet-particle collisions in mid-air are numerically investigated for a wide range of collision parameters: Weber number, contact angle and droplet/particle diameter ratio (4 ≤ We ≤ 150, 20° ≤ θeqi ≤ 160°, and Ω = 1/2 and 1). To perform these simulations in an efficient manner, a simple dual grid based adaptive mesh refinement (SDG AMR) strategy is proposed and implemented in our existing multiphase flow solver. A total of 90 collision cases are systematically analyzed and are compared with results for the case of impact on a stationary particle to understand how mid-air collision characteristics are changed relative to those on a stationary target. The simulation results show that mid-air droplet-particle collision behavior is significantly different from that of droplet collision on a stationary particle, thus the impact phenomena cannot be interpreted by extrapolating collision results for a stationary target.