Numerical Study of the Emission of Acoustic Energy of Single Collapsing Vapor Bubble near a Rigid Wall

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.