Interaction of bubbles in an ultrasonic running wave

Abstract

The influence of the initial sizes of two bubbles on their dynamics is studied under the action of a plane ultrasonic wave travelling along a straight line passing through the centers of the bubbles. The bubbles are filled with air, the liquid is water in room conditions. Initially the total volume of the two bubbles is equal to two volumes of a 5 μm bubble, the distance between the bubble centers is 30 μm. The wavelength is 5 mm, its amplitude is 0.3 bar. A mathematical model used is of fourth order of accuracy in terms of the ratio of the radii of bubbles to the distance between them. It allows for the small non-sphericity of the bubbles, the liquid viscosity and compressibility, the surface tension. It is shown that under the considered conditions three scenarios of the interaction of bubbles are possible: their collision, their divergence, and destruction of one of them due to large deformations of its surface. The ranges of a parameter characterizing the ratio of the initial radii of bubbles in which these scenarios are realized are revealed. The interaction scenarios are shown to depend on the arrangement of the bubbles.