COMPARISONS OF UNCOUPLED, FILM THEORETICAL AND EXACT-SOLUTIONS FOR BINARY DROPLET EVAPORATION AND CONDENSATION

The model for evaporation or condensational growth of a monodisperse binary droplet population is presented. Three methods for estimating steady state gas phase mass fluxes are compared. The uncoupled model neglects the coupling between mass transfer rates; the film theoretical model is based on an approximate approach and it is simpler to use than the exact model. The most significant discrepancies were found between the results given by the uncoupled and the more exact models for an ammonia-water droplet evaporating in helium atmosphere. The film theoretical model seems to predict the mass fluxes reliably when these are in different directions. The exact model is verified by comparisons with experimental literature data for the condensation of n-propanol-water droplets and the agreement is good.