The influence of size-distribution parameters on the evaporation of polydisperse dilute sprays

An analytical study has been performed of both diffusion-controlled and radiation-controlled (opaque droplets) evaporation of single-component polydisperse sprays. The overall evaporation characteristics of sprays of different initial size distributions were found to be correlated best by their initial Sauter mean diameter. In the case of diffusion-controlled evaporation, the representation of a polydisperse spray by a monodisperse spray of droplet size equal to the initial Sauter mean diameter of the polydisperse spray is a good assumption during the early stages of evaporation. When 40% of the volume of droplets has evaporated, the error of the monodisperse model reaches 20%. On the other hand, in the case of radiationcontrolled evaporation, the monodisperse spray model yields good results for most of the period of evaporation of the spray.