Comparison of measured and modelled droplet–hot wall interactions

In this study CFD simulations of both sessile droplets resting upon a vapour cushion and droplets bouncing off a hot solid surface are presented. As a droplet approaches a hot surface the vapour layer formed by evaporation from the droplet acts like a cushion and can prevent contact between the liquid and the hot surface. Rather than hitting and wetting the surface, the droplet can rebound from the vapour film. For the tracking of the interface between the two fluids a one-fluid Level Set method is used, embodied in the TransAT© finite-volume two-phase flow computational code. Inter alia, this incorporates a full Navier–Stokes solution in the region of the thin film. The method is used to analyse the experiments conducted by Wachters et al. [L.H.J. Wachters, H. Bonne, H.J. Van Nouhuis, The heat transfer from a horizontal plate to sessile water drops in the spheroidal state, Chemical Engineering Science 21 (1966) 923–936] and Biance et al. [A.-L. Biance, F. Checy, C. Clanet, G. Lagubeau, D. Quere, On the elasticity of an inertial liquid shock, Journal of Fluid Mechanics 554 (2006) 47–66]. Good agreement with the experimental observations is obtained.