Effect of over-pressure on the dynamics of interacting cavitation bubbles near curved surfaces in sub-cooled liquid nitrogen

In this study, we conduct direct numerical simulations to investigate the dynamics of interacting cavitation bubbles near a curved surface in liquid nitrogen, which serves as the surrounding fluid medium. Our simulations are carried out under both atmospheric and over-pressurized conditions, spanning pressures from 40 to 200 kPa above atmospheric pressure. We analyze the effects of over-pressure on bubble morphologies, oscillation periods, and the velocity of liquid micro-jets. Additionally, we briefly explore the shearing action of high-speed micro-jets as a means of material fragmentation for generating micro/nanoparticles in cryogenic environments. Finally, we propose a novel eco-friendly and sustainable approach for plastic waste recycling using cryo-comminution. We anticipate that our findings will contribute to an enhanced understanding of cavitation dynamics at cryogenic temperatures, with potential implications for both mitigating detrimental effects and harnessing cavitation for various applications.