CAVITATION BUBBLE IN COMPRESSIBLE FLUID NEAR THE RIGID WALL SUBJECTED TO THE ACOUSTIC WAVE WITH ARBITRARY INCIDENCE ANGLE IN THREE-DIMENSIONAL

A balanced cavitation bubble is released near the rigid wall in the sound field generated by the incidence plane wave and its reflecting wave. With the modified boundary integral equation, the dynamics of bubble is solved considering the compressibility of fluid in this paper. Also the Bernoulli equation as the boundary condition for cavitation bubble in sound field is deduced using Euler equation. Since the arbitrary incidence angle of acoustic wave, the three-dimensional model is utilized. The bubble will expand or contract at first according to the initial phase of acting acoustic pressure on bubble surface. And during the contraction phase, the liquid jet with high speed will be generated pointing to rigid wall but be deflected to the incidence direction of acoustic wave. The oblique degree of jet will be affected by the incidence angle and initial distance between bubble center and rigid wall. The oscillation amplitude of bubble will be affected by the incidence amplitude and incidence frequency, but be limited by the rigid wall. Since the compressibility of fluid, the perturbation will propagate to the far-field. Thus the oscillation amplitude of bubble will be reduced.