The effect of temperature dependence of density and mass diffusion coefficient on the mass transport from a drop evaporating in hot gaseous environment

Abstract

Species, energy and momentum conservation equations are solved in spherical symmetry and under ideal gas approximation, to yield an analytical model capable to evaluate the heat transfer and the evaporation rate from a drop under quasi-steady conditions, accounting for the temperature dependence of mixture density and diffusion coefficient. The model is applied to predict the evaporation rate from water and hydrocarbon droplets under pressure and temperature conditions of interest for applicative fields, like fire control and combustion. The results obtained by the proposed model are compared with those from the most commonly used ones where mass diffusion coefficient and gas density are kept constant to an average value.