High-speed visualization of acoustically excited cavitation bubbles in a cluster near a rigid boundary

Abstract

In the present work, high-speed visualizations at one million frames/s have been used to study the oscillation characteristics of acoustic cavitation bubbles. The bubbles are generated by acoustic cavitation using an ultrasound transducer with an excitation frequency of 75 kHz near a rigid surface and the medium used is deionized water. The cavitation bubbles tend to collect in clusters near solid boundaries, where they are visualized using a high-speed camera. The collective oscillations give rise to many interesting phenomena like bubble collapse, coalescence, fragmentation and bubble translation. The image sequences provided here contribute to the better understanding of the entire lifecycle of acoustic cavitation bubbles.