Dispersion of fine settling particles in a tidal wetland flow

Abstract

An investigation on transport of fine sediment particles in a tidal wetland flow is presented in the current research. The model of this work is based on an advection diffusion equation whose solution reveals the water phase based concentration of settling particles. Using the method of moments, a system of moment equations are derived from the governing equation. A finite difference implicit scheme is employed to solve the equations of moment. The behavior of Taylor effective dispersivity due to the variation of settling velocity of fine particles for oscillatory current with or without nonzero mean is predicted. The mean concentration distribution along the longitudinal direction is obtained using the Hermite polynomial and first four central moments. It is shown that for greater settling velocity, the dispersion procedure is inhibited. Some significant effects of vegetation factor, time period, oscillation parameter on environmental dispersivity, skewness and mean concentration profile are shown. The results of the present study are very important to understand the process of sedimentation and wastewater treatment in a tidal wetland flow.