Investigation of Neighboring Laser-Induced Cavitation Bubbles near Orifices

The antiphase generation of two neighboring cavitation bubbles results in the formation of a slow jet countered in the opposite direction by high-speed jet. The direction of the focused jet can be predetermined from the axis of the two bubbles whereas the speed of the jet can be controlled by modifying the relative bubble sizes, positions, and initiation times. In this study we explore the dynamics of neighboring same millimeter-sized bubbles generated in deionized water using two Nd:YAG 1064 nm wavelength, 6ns pulsed lasers. The two bubbles were modified antiphase to study the resulting jet through different orifice sizes and imaged with high speed shadowgraph at 10⁵ fps. Further, the resulting pressure waves are measured and compared to those released by an isolated cavitation bubble. The dynamics are observed and discussed with regards to natural diffusion and as potential application to micro-pumping.