Modelling of liquid drop heating and evaporation: the effect of drop shrinking

The process of heat and mass transfer from a spherical mono-component liquid drop evaporating into a gas environment is investigated, relaxing the commonly adopted quasi-steady approximation and accounting for the inherent unsteadiness caused by the sudden immersion of a liquid drop in a gaseous environment. The drop radius shrinking due to evaporation settles a moving boundary problem, which is transposed to a fixed boundary one by a proper coordinate transformation. The heat and evaporation rates and the drop diameter evolution are quantified by numerical solution of the species and energy conservation equations and the overall mass and energy balances over the drop for different species (water, n-octane, n-dodecane, ethanol).