Bubble-Jets in Gravitational Fields (APS DFD Video V060)

We show visualizations of the gravity-induced jets formed by spherical bubbles collapsing in liquids subjected to normal gravity, micro-gravity, and hyper-gravity. These observations demonstrate that gravity can have a significant effect on cavitation bubbles. An analysis of the gravity-induced jets uncovers a scaling law between the size of bubble-induced jets and the non-dimensional parameter grad(p)*R0/p, where R0 is the maximal bubble radius and p is the driving pressure. This scaling law applies to any jet formed in any uniform pressure gradient grad(p).