Influence of forced convection on the evaporation and internal dynamics inside of an array of salt solution droplets

Abstract

The effects of a gentle forced air convection on the internal dynamics of an array of multiple pinned sessile salt solution droplets are investigated via fully-coupled transient ALE finite element analysis. Results highlight the competition between the shear-induced circulation within the droplets and the gravity-driven flow in the droplets arising from increasing liquid density in regions of high water evaporation. At low air speeds, gravity effects dominate, resulting in a non-uniform concentration distribution. However, at higher speeds the shear-induced circulation within the droplets becomes sufficient to mix the liquid within the droplets via a 3D flow pattern, resulting in greater concentration uniformity. In addition, the shielding effect of leading droplets on downstream droplets is explored for various air speeds, with results showing differences in average concentration levels.