Flow focusing from interacting cavitation bubbles

This paper is associated with a video winner of a 2021 American Physical Society's Division of Fluid Dynamics (DFD) Milton van Dyke Award for work presented at the DFD Gallery of Fluid Motion. The original video is available online at the Gallery of Fluid Motion, https://doi.org/10.1103/APS.DFD.2021.GFM.V0038.

Figure 1

Time sequences for the shape evolution of interacting cavitation bubbles resulting in high-speed liquid jets, as visualized experimentally through high-speed imaging of a laser-induced bubble pair (a), numerically through high-fidelity direct numerical simulations displaying the pressure gradient field (b), and the velocity field with streamlines (c). Here, the maximum radius $R_{\max }$ of the bubbles is approximately 2.90 mm, and the temporal and spatial separations between the bubble generations are $\mathrm{\Delta }t=$ 278.50 $\mu \mathrm{s}$ and $d=4.50$ mm, respectively. For the video associated with this figure, see https://doi.org/10.1103/APS.DFD.2021.GFM.V0038.