Droplets skating on gas nanofilms: merging, wetting, bouncing & levitation

Recent advances in experimental techniques have enabled remarkable discoveries and insight into how the dynamics of thin gas/vapour films can profoundly influence the behaviour of liquid droplets: drops impacting solids can “skate on a film of air”, so that they can “bounce off walls”; reductions in ambient gas pressure can suppress splashing and initiate the merging of colliding droplets; and evaporating droplets can levitate on their own vapour film (the Leidenfrost effect). Despite these advances, the precise physical mechanisms governing these phenomena remains a topic of debate. In this talk, I will overview our development of efficient computational models for the aforementioned droplet dynamics in the presence of gas nanofilms into which gas-kinetic, van der Waals and/or evaporative effects can be easily incorporated in order to address these open problems and stimulate new directions of research.