Modeling bubble collapse anisotropy in complex geometries

A gas or vapor bubble collapsing in the vicinity of a rigid boundary displaces toward the boundary and produces a high-speed jet directed at the boundary. This behavior has been shown to be a function of the anisotropy of the collapse, measured by a dimensionless representation of the Kelvin impulse known as the anisotropy parameter [Supponen et al., J. Fluid Mech. 802, 263 (2016)]. However, characterization of the anisotropy parameter in different geometries has been limited to simplified analytic solutions. In this work we develop an inexpensive numerical model, based on the boundary element method, capable of predicting the anisotropy parameter for any rigid complex geometry. We experimentally explore a robust measure of bubble displacement, showing that the bubble displacement in a range of complex geometries behaves as a single function of the predicted anisotropy parameter values.

Automated summary

In this study, an inexpensive numerical model based on the boundary element method was developed to predict the anisotropy parameter of gas or vapor bubbles in complex rigid geometries. Experimental results showed that bubble displacement in a range of complex geometries behaves as a function of the predicted anisotropy parameter values.