Monte Carlo Simulations of Drop Growth by Accretion

Abstract

Statistical effects in the growth of drops by accretion are reexamined using Monte Carlo simulations of the stochastic growth process. In the simulations, up-to-date fallspeeds and collision efficiencies are used to evaluate the capture probabilities. The stabilized distribution of growth times is obtained from the simulations and, from it, size distributions are deduced. The effects of varying initial drop size and droplet size in a random, monodisperse cloud are investigated in detail. It is found that for droplet radii between 8 and 14 ?m, statistical effects are unimportant for drops initially larger than 40 ?m radius but become very significant for initial radii smaller than 30 ?m.