关键词: bubble dynamics, bubble—bubble interaction, mass exchange, ultrasound waveform

Abstract: We present a dynamic model of cavitation bubbles in a cluster, in which the effects of evaporation, condensation, and bubble—bubble interactions are taken into consideration. Under different ultrasound conditions, we examine how the dynamics of cavitation bubbles are affected by several factors, such as the locations of the bubbles, the ambient radius, and the number of bubbles. Herein the variations of bubble radius, energy, temperature, pressure, and the quantity of vapor molecules are analyzed. Our findings reveal that bubble—bubble interactions can restrict the expansion of bubbles, reduce the exchange of energy among vapor molecules, and diminish the maximum internal temperature and pressure when bursting. The ambient radius of bubbles can influence the intensities of their oscillations, with clusters comprised of smaller bubbles creating optimal conditions for generating high-temperature and high-pressure regions. Moreover, an increase in the number of bubbles can further inhibit cavitation activities. The frequency, pressure and waveform of the driving wave can also exert a significant influence on cavitation activities, with rectangular waves enhancing and triangular waves weakening the cavitation of bubbles in the cluster. These results provide a theoretical basis for understanding the dynamics of cavitation bubbles in a bubble cluster, and the factors that affect their behaviors.

Key words: bubble dynamics, bubble—bubble interaction, mass exchange, ultrasound waveform