Effect of Multiple Cavitation Bubble Configurations on the Collapse Behavior and the Wall Damage

Cavitation often involves the formation of bubble clusters near walls in natural and engineering environments. The collapse dynamics of these clusters are highly complex due to mutual interactions and coupling. Although studies of single and double bubbles near walls have advanced considerably, the coupling mechanisms in multiple cavitation bubble systems remain inadequately understood. In this paper, a coarse-grained force field is employed to investigate multiple cavitation bubble collapse in free domains and under Configuration II (near-wall). The paper systematically analyzes the collapse patterns and the concomitant variations in the system pressure and wall pressure to elucidate the underlying interaction mechanisms. The results show that the time when the highest liquid peak pressure occurs for Configuration II (regular triangle) and Configuration III (inverted triangle) is 0.92 and 1.78 ps, respectively, with a time difference of nearly a factor of 2. The maximum liquid peak pressure in Configuration II is approximately 1.9 times that under Configuration III. The time when the peak pressure on the wall occurs due to the bubble collapse is basically the same under the three configurations, but the peak pressure on the wall of Configuration II is the largest, reaching 22.39 GPa, which is 1.12 and 1.14 times that of Configuration I and Configuration III, respectively. This paper advances cavitation theory and provides crucial technical support, offering guidance for optimizing hydrodynamic cavitation processes in industrial applications.