THE DIFFUSION-CONTROLLED GROWTH OF AN AEROSOL IN A TURBULENT MEDIUM

Abstract

The growth rate and radius of an aerosol particle in a turbulent supersaturated fluid are calculated on the basis of a simple ?stagnant film? model, in the presence of time-dependent, homogeneously distributed sources in the diffusion field. The limiting growth law leads to a three-halves power dependence of the radius upon the time. The collapse of the supersaturation due to competition for molecules of the diffusing species among an initially monodisperse, homogeneous and random distribution of aerosol particles leads to an asymptotic-in-time limiting critical radius. The critical radius attained is equal to the corresponding critical radius of an aerosol particle growing in an infinite volume of fluid at rest. The distribution of initially mono-disperse aerosol particles remains monodisperse throughout the growth process. The application of the theory to the growth of water droplets in a turbulent cloud is indicated.