Experimental and Three-Dimensional Numerical Study of the Single/Multiple Sessile Droplets Evaporation

In this work, a three-dimensional numerical simulation, accompanied by an experimental study, of the evaporation of one or more nonaligned liquid droplets deposited on a solid substrate and surrounded by air was produced. In addition to the central droplet, the behavior of other neighboring droplets was tracked. Evaporation of a single droplet S was compared with that of multiple droplets (a droplet C surrounded by four nonaligned droplets). The shielding effect exerted by the four droplets on the droplet C increases the life of the latter by 83% as compared to a single droplet. Evaporated flow of the droplet C is reduced by 58% compared to the case of the isolated droplet S. The droplets at the extremities evaporate faster (compared to the droplet C, the evaporated volume can increase up to 57%), since they have less interaction with nearby droplets. A geometric coefficient F characterizing the ratio of the distance separating two neighboring droplets, to the diameter of a droplet was introduced. The shielding effect decreases with the increase of F. For F greater than 5, the behavior of the extremity droplets tends toward that of a single droplet.