Experimental investigations of interactions between a laser-induced cavitation bubble and a spherical particle

In the present paper, the interactions between a cavitation bubble and a spherical particle are experimentally investigated with the aid of high-speed camera. The cavitation bubble is generated by a focused laser beam with the bubble size adjusted through energy dissipater. A series of experimental work is conducted with variations of the bubble sizes, the particle sizes and the distance between the bubble and the particle. Based on the collapsing process of cavitation bubble near the particle, three cases (mushroom-shaped, pear-shaped and spherical-shaped collapses) are quantitatively identified and the criterions for separating three cases are also given in terms of non-dimensional parameters. Furthermore, transitions between the aforementioned cases during parameter variations are also shown together with several examples. Finally, some special cases (e.g. collapse of two bubbles near the particle) are also discussed with typical collapsing process shown.