We present experiments and direct numerical simulations of the break-up of bubbles in a turbulent flow. The turbulent flow induces bubble deformation, creating a neck that then pinches off giving birth to child bubbles. We focus on the transition from the deformation regime controlled by the turbulent fluctuations to the final universal pinch-off, which present a self-similar dynamics, similar to the one reported in bubble pinch-off in still water. We characterize the large scale deformation of the bubble by its aspect ratio and observe fluctuations at the order of the eddy turnover scale, while the final pinch-off starts above a critical deformation, typically one millisecond prior to break-up. Over this last millisecond, the necking follows a universal self-similar behavior, independent of the turbulent flow.
Available at: http://works.bepress.com/wouter-mostert/3/