Repelling cavitation bubbles: Modeling jet dynamics near a gas-filled hole

Cavitation bubble collapse near solid surfaces can cause severe erosion, noise, and vibrations. We investigate how a gas-filled hole in a solid surface influences the migration of the bubble as it collapses. While non-dimensional parameters have been previously derived to describe bubble–surface interaction near rigid or free boundaries, such models do not capture mixed-boundary effects. Building on prior experimental observations using high-speed imaging, we now present an analytical model based on Kelvin impulse theory tailored to a surface with a gas-filled hole. From this framework, we derive a non-dimensional parameter that predicts jet strength and correlates with bubble displacement across a range of bubble-to-hole diameter ratios. The theory developed is well supported by our experimental data. These insights can inform the design of passive surfaces that mitigate cavitation damage through controlled bubble behavior.