Aerosol Generation by the Splashing of Low Viscosity Drops Impacting Liquid Layers

Using theory and numerical simulations, here we describe the early stages of the impact with a velocity V of a drop of radius R_{d} of a low viscosity liquid such as water against a layer of generic thickness H of the same liquid. Our predictions for the initial velocity V_{t}≫V and the diameter H_{t}≪R_{d} of the toroidal rim bordering the edge of the thin lamella which is ejected radially outwards after the impact, are in fair agreement with both the numerical results and also with the experimental measurements reported by Zhang et al. [J. Fluid Mech. 690, 5 (2012)JFLSA70022-112010.1017/jfm.2011.396]. Consequently, the present findings can be employed, for instance, to predict the initial diameters and velocities of the fastest tiny droplets which are ejected right after a rain drop falls on a liquid pool, an ubiquitous phenomenon with implications in the dispersal of contaminants and in the generation of aerosols and of ice condensation nuclei.