Experimental study on the interaction of a cavitation bubble flanked by two particles

Cavitation erosion and abrasion are the two main forms of flow-induced damage in hydraulic machinery. Coupling failures occur when devices are operating under liquid–solid two-phase flow. The interaction between cavitation bubbles and solid particles is the crucial aspect. Whereas conventional studies focus on the single particle–bubble interaction, in the present work we go beyond such interactions and address the interaction between a cavitation bubble and a pair of particles to provide a new perspective on this complex interaction. A series of experiments were performed in which two particles interact with a spark-induced bubble. The subsequent collapse of this cavitation bubble and the motion of the particles were recorded and analyzed in detail. The results suggest that, during the cavitation bubble collapse into a cluster of smaller bubbles, the particles influence the location of this collapse. The relative motion of the particles with respect to the cavitation bubble depends strongly on their initial separation. For particles of the same size, the characteristics of the dynamics exhibit a clear symmetry; for particles of different sizes, a cavitation jet forms and propagates toward the surface of the larger particle, which results in a large displacement. This study sheds light on how two particles flanking a cavitation bubble affect its collapse.