Modeling of Pollutant Transport in Compound open Channels

Abstract

In this paper we describe the development and validation of a 2-D finite-difference mathematical model for simulating inert pollutant transport in compound channels. In its formulation the model couples depth-averaged (depth-integrated) versions of the classical 3-D Navier-Stokes equations and the advection-diffusion equation with constant eddy-viscosity model. The numerical solution scheme is Platzman’s space-staggered scheme, and a double time step operation is employed in the analysis. The model is initially validated using laboratory data of continuous-injection dye tracer experiments performed in a large asymmetrical compound-shaped channel at the Hydraulics Laboratory, University of Ottawa. Comparison between predicted and observed dye concentration curves indicates generally good agreement in the overall shapes of the curves, as well as in the peak concentrations and the times to peak.