Holey surfaces repel cavitation bubbles*

Cavitation bubbles pose significant challenges in various engineering applications due to the erosion, noise, and vibrations they induce upon collapsing on or near solid surfaces. In this study, we explore the potential of solid surfaces with gas-filled holes to repel cavitation bubbles and mitigate their negative effects. While existing research shows that surfaces with gas-filled holes repel collapsing bubbles, a comprehensive understanding for design is lacking. We investigate a wide range of bubble-to-hole diameter ratios and bubble-hole relative positioning to identify when a solid surface with a single gas-filled hole repels cavitation bubbles. Using high-speed photography, we capture the bubble behavior near these surfaces, which are generated by a pulsed laser. We summarize the results by developing behavioral regime plots for bubble repulsion. Our research on this mechanism may inspire novel surface designs for bubble repulsion to prevent cavitation damage, noise, and vibrations.