Computer Simulations of Homogeneous Deposition of Liquid Droplets

Abstract

Understanding the deposition of liquid droplets on surfaces is essential in many environmental and industrial processes. In this paper, we describe computer simulations of homogeneous deposition of liquid droplets on an ideal, smooth, and horizontal solid surface. The statistical evolution of droplet deposition and growth processes are investigated. It is found that three basic events, namely, deposition, incorporation, and coalescence, produce droplets of different sizes and that the droplet size polydispersity is continuously increasing with time leading to a bimodal distribution. By considering the total number of droplets N t o t on the surface versus time, we demonstrate that four growth regimes must be considered. These regimes reflect the relative influence of the three events during the deposition process. Variation with time of the surface coverage Γ as a function of the contact angle θ between the droplets and the surface is also investigated. The effect of a variable contact angle on the value of surface saturation and dynamical growth is calculated. Finally, by considering the total mass of the deposited material and surface coverage, some guidelines to achieve an efficient droplet deposition process and surface coverage versus total droplet mass are proposed.