Experimental study of influences of a particle on the collapsing dynamics of a laser-induced cavitation bubble near a solid wall

In the present paper, the collapsing dynamics of a laser-induced cavitation bubble between a spherical particle and a solid wall is fully revealed using a high-speed camera based cavitation experimental system. For the purpose of comparisons, experiments of cases without the presence of the particle are also conducted and demonstrated. Influences of several paramount parameters (including the bubble radius, the particle radius, and the relative positions among the bubble, the particle and wall) on the bubble collapsing dynamics, the motions of bubble boundaries and the positions of the bubble centroid are all investigated. Based on the directions of the micro-jets during the bubble collapse, the bubble collapsing behavior could be categorized into three cases with their primary characteristics revealed. Furthermore, the transitions among three different cases are clearly demonstrated using several examples in terms of high-speed photography. Based on a large amount of experimental data, quantitative discussions on the parameter zone of the identified three typical cases are given in terms of the three non-dimensional parameters. Generally speaking, the particle scale does not show significant influences on the bubble dynamics behavior except some special positions of the bubble.