Diffusional Processes in the Growth of Aerosol Particles

Abstract

Various theoretical problems encountered in the diffusional growth process of aerosol particles have been investigated. Fick's differential law with a modified boundary condition has been shown to be approximately valid even where the mean free path of the diffusing molecules is long compared to the radius of the aerosol droplet. A new method has been developed for handling the case of a plurality of competing sinks in the diffusion field. The contribution of a time‐dependent uniform source function to the flux into the sinks has been calculated by a method which enables account to be taken of the transient in concentration due to the diffusion process. Such a time‐dependent source function representing a change in the number of molecules available for diffusion, will arise because of temperature changes in the diffusion field in the aerosol growth problem.