Dynamics of Laser-Induced Bubble in Pressurized Liquid Nitrogen.

Abstract

The dynamics of a laser-induced bubble in liquid nitrogen is studied experimentally. The motion of an almost spherical bubble, formed under appropriate control of optical conditions, is visualized by high-speed photography. Low subcooled liquid nitrogen at 78.0 K is used; the resulting high vapor pressure inside a bubble causes motion different from that in water at normal temperatures. Pressure is applied to liquid nitrogen to increase the degree of subcooling. An induced bubble grows similarly to a Rayleigh bubble under the effect of liquid inertia. The high vapor pressure, however, retards the collapse from the Rayleigh's solution, and makes the bubble surface rough by Taylor instability coupled with themodynamical effect. Estimation of the cavitation parameter in experiments of liquid nitrogen and water enables us to understand the transition from the motion being heat transfer dominant to that being liquid inertia dominant.