AN INVESTIGATION ON THE BEHAVIOR OF LASER-INDUCED BUBBLE IN CRYOGENICLIQUID-NITROGEN

There have been few experimental reports on cryogenic two-phase fluids and cavitation phenomena using the irradiation of pulsed high-power l aser. This paper describes an investigation of the behavior of laser i nduced cavitation bubble in cryogenic liquid nitrogen. The bubble is p roduced by a pulsed ruby laser focused in the special cryostat. The pr oduction, growth, and rebound phenomena of the bubbles are visualized by diffusive shadowgraph technique with an image-converter camera. To compare with the experimental results, a numerical study has also been performed on the dynamics of a single spherical bubble in liquid nitr ogen under the conditions of nonequilibrium phase change.