Analysis of suppressive effect of large bubbles on oscillation of cavitation bubble in cavitation field

Abstract

In this paper, the interaction of multiple bubbles in the cavitation field is investigated in combination with the phenomenon of small bubbles hovering around large bubbles observed experimentally. A model composed of three bubbles is developed and the dynamic behavior of cavitation bubble is analyzed. By considering the time delay effect of the interaction between bubbles and the nonspherical oscillation of large bubbles, the modified bubble dynamic equations are obtained. Numerical results show that the nonspherical effect of large bubbles has little effect on the oscillation of cavitation bubble. The suppressive effect of large bubble on cavitation bubble is closely related to the radius of the large bubble. The larger the size of the large bubble, the stronger the inhibition. When the size of large bubble is close to the resonant radius, the oscillation of cavitation bubble appears coupled resonance response, and the maximum expansion radius of bubble appears resonance peak. The distribution of the secondary Bjerknes force with bubble radius and the separation distances is strongly influenced by driving frequencies or sound pressures. When the large bubble is in the submillimeter order, the strength of the secondary Bjerknes force and the acoustic response mode are different due to the different strength of the nonlinear response of the cavitation bubble. As the distance decreases, when the acoustic pressure increases to a certain value, the secondary Bjerknes force on the cavitation bubble decreases due to abnormal acoustic absorption. The secondary Bjerknes force on cavitation bubble is likely to be repulsive at different separation distances. The theoretical results accord well with experimental phenomenon.