Gas effects in cavitation bubbles collapse*

Since the first development of the cavitation bubbles collapse model by Lord Rayleigh, the role of the bubble content on its dynamics has aroused great interest. Despite several attempts have been made to explain the effective gas-related damping mechanisms of a collapsing bubble, the contribution of each dissipation mechanism is not yet fully understood. In this study, the dynamics of highly-spherical single cavitation bubbles generated in aqueous-ammonia solutions have been recorded over a wide range of ammonia concentrations. The comparison of experimental data with a simplified analytical model will be used to clarify the role of gas content on the various stages of the bubble collapse process. The results distinctly revealed the important influence of the dissolved gas on the bubble dynamics, as well as on its contribution to the effective damping occurring at the final collapse stage. Moreover, the simplified model allows to estimate the average bubble internal pressure from experimental results.