A compressible two-phase solver considering phase transition and thermodynamic effects is developed on OpenFOAM to numerically investigate the dynamics of single cavitation bubble collapse near the rigid wall. A grid independence analysis is conducted, and the accuracy of the pressure field is verified by comparing the numerical results with the experimental results. The emission process of acoustic energy during the bubble collapse is discussed. Moreover, the acoustic radiation energy in the flow field under different dimensionless bubble-wall distances $\gamma$ is further studied, which is related to the mechanism of cavitation erosion. The results show that $\gamma -$value has a significant effect on the amplitude of acoustic energy. The maximum amplitude of acoustic energy accounts for 8% to 25% of the total energy in the flow field when $\gamma -$value ranges from 0.1 to 2.0. The amplitude of acoustic energy decreases with $\gamma$ in the range $0.1<\gamma <0.9$ while increases with $\gamma$ in the range $0.9<\gamma <2.0$.

This study numerically investigates the interactions between a collapsing bubble and a movable particle with a comparable size in a free field, which is associated with the microscopic mechanisms of the synergetic effects of cavitation erosion and particle abrasion on the damages of materials in fluid machineries. A new solver on OpenFOAM based on direct numerical simulations with the volume of fluid (VOF) method capturing the interface of a bubble and with the overset grid method handling the motion of the particle was developed to achieve the fluid–structure interaction (FSI). The results show that bubbles in cases with stand-off parameter $\chi$ (defined as ($d_0-R_p)/R_0$), where $d_0$ is the initial distance between the centers of the bubble and particle, and $R_p,R_0$ are the particle’s radius and the initial radius of the bubble respectively >1, experience spherical-shaped collapse under the influence of the approaching particle, which is attracted by the collapsing bubble. The bubbles in these cases no longer present non-spherical collapse. Additionally, a force balance model to account for the particle dynamics was established, in which the particle velocity inversely depends on the size of the particle, and approximately on the second power of the initial distance from the bubble. This analytical result accords with the numerical results and is valid for cases with $\chi >1$ only, since it is based on the theory of spherical bubbles. These conclusions are important for further study of the interactions between a bubble and a movable particle near a rigid wall.