Analysis of energy conversion and mass damping of synchronized and same-size multibubble

Multibubble formation is a common phenomenon. In this paper, a model of a multibubble accounting for heat transfer, phase change, and bubble–bubble interaction through bubble-induced pressure waves is proposed. Numerical simulations are conducted using this model to investigate the dynamic behavior, energy conversion over each cycle, mass damping of one bubble in a synchronized and same-size multibubble, and the Bjerknes force between two bubbles in a multibubble. Here, one cycle is defined as the interval between two adjacent time points corresponding to peak radii, and a nondimensional parameter γ representing the interaction strength is defined. The model is validated, and a formulation of the collapse time accounting for bubble–bubble interaction is derived. Bubble–bubble interaction extends the collapse time and increases the peak temperature and pressure of the collapsing bubble during its first cycle. On the one hand, the results reveal attenuation of energy conversion due to pressure work, thermal conduction, and phase change over each cycle, as well as mass damping of one bubble in a multibubble. It is found that most of this attenuation occurs during the first three or four cycles. On the other hand, energy conversions due to pressure work and phase change over the first cycle increase with increasing γ, but that due to thermal conduction over this cycle decreases. Furthermore, the Bjerknes force is also subject to damping similar to that of energy conversion over each cycle.