Dynamic behaviors of a laser-induced bubble and transition mechanism of collapse patterns in a tube

Abstract

The pulsation of cavitation bubbles under constraint conditions has complex dynamic characteristics and has been widely applied in various fields, such as liquid pumping, underwater propulsion, and clinical applications. In this study, the dynamic behaviors of a laser-induced bubble in a tube are investigated under different initial conditions. A high-speed optical visualization is carried out in the experiments. The numerical simulation based on the volume-of-fluid method is implemented on the open source code OpenFOAM. From the experimental observation and numerical analysis, an axial jet pointing toward the front end of the tube is generated during bubble shrinkage. According to the type of the axial jet, the collapse patterns are classified into three regimes: one-dimensional, transitional, and three-dimensional. Furthermore, it is also found that the normalized initial energy of the bubble and the length-to-diameter ratio affect the maximum length and the pulsation period of the bubble. Finally, the transition mechanism of the collapse patterns from one dimension to three dimension is obtained through a phase diagram by combining experimental observations with numerical simulation.