Dynamics and mechanisms of single bubble cleaning in low-frequency ultrasonic field

Ultrasonic cleaning has been an important application in our common life since the invention of ultrasonic cleaners in the 1940s. Nowadays it is well known that the dynamics of cavitation bubbles near the surface are closely related to the cleaning efficiency, but the details remain partly speculative. At first, the liquid jet impact and collapse shock waves of cavitation bubble were considered as the main reasons of cavitation erosion or surface cleaning. But others later found that the high shear forces during liquid jet spreading (after impact) on the surface plays the main role in most surface cleaning applications. In the present work, we want to focus on the roles of different force during single bubble cleaning to help to reveal the correlation between single bubble dynamics and surface cleaning process. We seek to elucidate the physical mechanisms by which a bubble can clean the surface characterized by film detachment.