Modeling and simulation of droplet evaporation using a modified Cahn–Hilliard equation

In this paper, we propose a mathematical model, its numerical scheme, and some computational experiments for droplet evaporation. In order to model the evaporation, a classical Cahn–Hilliard equation with an interfacial evaporation mass flux term is proposed. An unconditionally gradient stable scheme is used to discretize the governing equation, and the multigrid method is applied to solve the resulting system. The proposed model is first validated via a proper interfacial parameter ϵ, and then, the effect of evaporation rate and effect of contact angle on volume and surface area changes are investigated. The numerical results indicate that the dynamics of evaporation are dependent on the contact angle on a solid substrate.