Experimental Investigation on Destructive Potential of Shock-Induced Bubble Collapse

The present study experimentally investigates shock-induced collapse of bubbles near boundaries of different plasticity and the resulting destructive erosion. Air bubbles held in gelatin are placed close to either a solid wall or a soft clay layer. High pressure impulse generated by a shock tube is employed to trigger bubble collapse. The bubble deformation is visualized by a focused shadowgraph system, and the damage caused to the boundary surface is closely examined as well. The collapse of bubbles near the soft clay layer shows differences from that near the solid wall in both qualitative description of bubble deformation and quantitative measurement of bubble dynamics. The surface of the clay is marked by the bubble collapse with a volcano-shaped imprint and some material floats into the gelatin in a mushroom shape. In this ongoing investigation, refined results under well-defined and uniform initial conditions will be provided and well suited for validation of numerical models and approaches.