The Development And Collapse Process Of Acoustic Cavitation Bubble

Acoustic cavitation refers to the formation of tiny bubbles under certain pressure within a liquid, their turbulence and surge in response to change of acoustic pressure, or their subsequent growth, shrinkage and collapse when ultrasound travels across the liquid. The acoustic cavitation is a very complex process. The collapse of the cavitation bubble due to the ultrasonic could arouse many physical and chemic effects such as accelerating the chemic reaction, destroying the biologic organization, generating the luminescence. Therefore, the research of the generation and the motion of the cavitation bubbles are very important.The numerical calculation of the development and collapse process of the acoustic cavitation bubbles and the moments on the boundary on various conditions are preset in this pape. The calculation of the movements of the acoustic cavitation bubbles in different radius and frequencies conduct a conclusion that if the radius of the cavitation bubble smaller than the resonance radius, the effect of cavitation can be enhanced, however, it is uncertainty that if enhance the frequency of the sound field only. The influence of viscosity and surface tension to the acoustic cavitation bubbles is unconspicuous, but the max radius and the maximum temperature will be reduced with the growing of the viscosity and surface tension. In order to research the influence of the kinds of gas, we calculated the fllowing situation: K = 1.67, K = 1.02, K= 1.4, and found that the K is much bigger , the effcet is much better. So we should choose the gas whose K is bigger. We calculated two situation: PA < P0 ,PA≥P0 to compare the movement of acoustic cavitation bubble uder different sound intensity. The acoustic cavitation bubble can collapse in one-period, when PA≥P0, but it is uncertainty that if enhance the sound intensity of the sound field only. Various signals acting on the acoustic cavitaion bubbles has been studied and the results show that the radius of the bubble which is stimulated by square signal is the biggest and the radius of the bubble which is stimulated by triangular signal is the smallest.The way to enhance the effect of ultrasoic cavitationc is also discussed in this article. We can enhance the the effect of ultrasoic cavitationc by reducing the ambient temperature and improving the sound intensity in experiment .