CLUSTER GROWTH BY DIFFUSION-LIMITED AGGREGATION IN SHEAR-FLOW

A two-dimensional square lattice computer model was used to study the cluster growth process by irreversible aggregation on the boundary of a shear flowing colloidal solution. The trajectories of the aggregatin g particles are determined by both a diffusion component and the strea mlines of the flow. The streamlines were obtained by iterative solutio n of the Navier-Stokes equation. For zero drift (the case of simple DL A), the horizontal growth of the aggregates is symmetric, but even a v ery weak drift breaks down this symmetry considerably. The fractal dim ensions obtained in the cases of zero and nonzero drift seem to be sli ghtly different: 1.67 and 1.78, respectively.