Brownian coagulation in the transition regime

Abstract

The rate of Brownian coagulation of aerosols is studied theoretically. The particle distribution function is assumed to be governed by the Fokker-Planck equation, which is solved analytically by the 13-moment method of Grad. An expression for the coagulation parameter β( a i , a j ) is obtained from the solution over all ranges of particle radii a i and a j . The coagulation rates predicted by the solution agree closely with those predicted by the empirical expression of Fuchs as well as with those recently obtained experimentally by Chatterjee, Kerker, and Cooke.