Effect of micro-bubble in ultrasonic field on microstreaming of elastic particle

Abstract

In this paper, the interaction between elastic particle and cavitation bubble is considered, the expression of microstreaming velocity and shear stress around the elastic particle are derived by using the theory of acoustic scattering. Taking into account the two predominant modes of elastic particle: <i>n</i> = 0 mode and <i>n</i> = 1 mode, the effects of the distance and the ratio of the radius and the relative position on microstreaming distribution, and the effects of the particle radius and the driving frequency on shear stress distribution are investigated. It is demonstrated that the interaction can increase the amplitude of microstreaming velocity, especially the tangential component of microstreaming velocity, and the shear stress. As the distance between elastic particle and cavitation bubble increases, the interaction weakens and the amplitude of the microstreaming velocity around the elastic particle decreases. When the bubble is in resonance, the microstreaming velocity around the elastic particle is significantly enhanced. The shear stress of the particle is affected by the particle radius and the frequency of sound field. As the particle radius and the frequency of sound field are larger, the external scattering sound becomes stronger and the amplitude of shear stress on the surface of particles turns larger.