Numerical Simulation of three Laser-induced in-phase bubbles

摘要

The potential applications of laser-induced bubbles are gradually revealed. And the performance of multiple - bubblesalso attracted considerable attention. This paper is intended to study the complex interaction among three in-linearranged in-phase bubbles. This work illustrates the interactions of three bubbles oscillation and the shockwave motionafter the recombination of the plasma nanosecond laser excited. The Volume of Fluid (VOF) model is used tonumerically analyze the behaviour of same equilibrium size, same distance and in-phase multiple-bubbles, which enablestracking of the gas-liquid interface and the field. The numerical results indicate that, in the expanding stage, due to thepressure gradient, bubbles at both ends move towards the centre, while the bubble surfaces facing to other bubbles getflattening. The central bubble has longer oscillation period than the side bubbles. In the shrinking stage, the side bubblesget deformation faster, and then collapse with a jet or get adhere to the central bubble. The initial high-pressure bubbleradiates a shockwave at the beginning of the expansion. The shock wave propagates outwards from the point source in acircular pattern, resulting in interference in the overlap of the two shock waves. A curved pressure wave, which isparallel to the in-line array, is produced by the interference of multiple shock waves. The pressure wave decays to anacoustic wave after a certain distance according to its initial intensity. In particular, a significant variable γ=D/(R+R)deserves studying in this progress.