Wouter Mostert (University of Oxford)

When two bodies of liquid collide, many interesting dynamics arise from the resulting fragmentation into droplets. Besides their inherent beauty, these dynamics also have relevance to processes of interest to science and engineering ranging from inkjet printing to breaking ocean waves. In this presentation I present direct numerical simulations of an idealised splashing process featuring two mutually colliding cylinders of liquid (in an ambient gas), under conditions characterised by a set of dimensionless parameters including the Weber (We), Laplace (La), and, indirectly, Bond (Bo) numbers, as well as characteristics of the initial perturbation. The collision results in the growth of a liquid rim, which destabilises into a set of ligaments which simultaneously fragment and merge, resulting ultimately in a statistical size distribution of small droplets resembling a power law. I will talk about some of the central dynamics and scaling behaviours of the problem, before concluding with a discussion on potential interpretations and applications to breaking ocean waves in particular.