3-D simulation of flocculation-settling of cohesive fine sediment

Since it is difficult to observe the flocculation-settling of cohesive fine sediment this complicated process is numerically simulated based on fractal growth theory by using an improved Reaction Limited Cluster-Cluster Aggregation(RLCCA) model.Some factors such as the fractal structure and permeability of flocs,effect of sediment concentration on fluid viscosity,etc.are carefully considered.The Brown motion,gravity settling,collision and cohesion of particles and clusters are simulated in the 3-D space.Based on the analysis of statistical data obtained from this numerical calculation experiment the various characteristics of flocculation-settling process are discussed.It is found that a type of similarity exists in the growing process of flocculation-settling in different layers of the suspended system.