EVAPORATION AND GROWTH DYNAMICS OF A LAYERED DROPLET

A mathematical model has been formulated for the evaporation and growth of a two-phase isolated droplet of two partially miscible components, exposed to a stagnant gas phase. Unsteady-state transport equations of the two components in the core, shell and gas phases have been rigorously treated. The resulting mathematical model involving two moving boundaries at the core-shell interface and the droplet-gas interface has been solved numerically for various conditions. Effects of critical parameters on the droplet dynamics have been examined. In a vapor free atmosphere where both components evaporate, the results show that the core either grows or evaporates depending on the physical parameters. When the core evaporates, either the shell or core disappears first, leaving a single-phase droplet. The study shows that the volatility of the components, thermodynamic and transport parameters greatly influence the evaporation behavior of a layered droplet.