Bouncing vs penetration of a particle through fluid interface

Capturing small particles by air bubbles is fundamental to understanding numerous industrial processes of multiphase fluid. In the simple limit of a bubble-sphere interaction, we consider a solid sphere impinging onto a free surface inside the bath of fluid. Experimentally, we observe two main regimes of particle-interface interactions that depend on the initial particle kinetic energy: bouncing and penetration, with a clear transition point from one to the other. Specifically, we find two distinct scalings for change in Weber number versus initial Weber number for the two regimes. In this talk, we present the novel experimental findings and theoretical justifications.