Diffusion-limited aggregation in three dimensions

Abstract

We study by numerical simulation the aggregation of particles in three dimensions according to the model introduced by Witten and Sander. We find a Hausdorff dimension of 2.39\ifmmode\pm\else\textpm\fi{}0.18 by examination of the density-density correlation function. We show that random electrical charges added to the aggregating particles change short-range properties of aggregates but the long-range behavior is unchanged. These results disagree with the observed properties of real aggregates such as soot and metallic smokes.