Numerical investigation of the interactions between a laser-generated bubble and a particle near a solid wall

The interactions between the bubbles and the particles near structures are important issues for the applications of the cavitation in the fluid machinery. To study the hidden microscopic mechanisms, a numerical method for simulating the laser-generated bubble between the solid wall and a particle is developed in this paper with considerations of the viscosities and the compressibility of the gas and the liquid phases, as well as the surface tension between them. The gas-liquid interface is tracked by the coupling level set and the volume of fluid (CLSVOF) method. The numerical results clearly reveal that the particle can influence the cavitation bubble behaviors. The potential damage of the nearby structures is numerically quantified in terms of the wall pressure, which helps better understand the synergetic effects of the particle on the cavitation. The effects of three dimensionless parameters on the wall pressure are also investigated, especially, on the peak pressure, namely, gamma(1) (defined as L-1 / R-max, where L-1 is the distance from the center of the initial bubble to the solid wall and R-max is the maximum bubble radius), gamma(2) (defined as L-2 / R-max, where L-2 is the distance from the lower surface of the spherical particle to the initial bubble center) and theta (defined as R-p / R-max, where R-p is the spherical particle radius). Further numerical results show that these parameters play a dominant role in determining the peak pressure. When gamma(1) < 1.00, the peak pressure on the solid wall during the bubble collapse is mainly resulted from the liquid jet. When gamma(1) > 1.00, the peak pressure is caused by the shock wave. With the increase of theta or decrease of gamma(2), the peak pressure increases. When gamma(2) > 2.00, the effect of the particle on the bubble behavior can be neglected.

Automated summary

A numerical method for simulating laser-generated bubbles between solid walls and particles has been developed in this study to investigate the effects of particles on the behavior of cavitation bubbles. The potential damage to nearby structures has been quantified through numerical calculations.