Turbulence Modeling of Flood Plain Flows

Abstract

A numerical model capable of predicting flow characteristics in a compound channel is described. The model solves the continuity and momentum equations along with the transport equations of kinetic energy of turbulence and the dissipation rate. Closure is achieved With the aid of algebraic relations for turbulence stresses. The model is capable of treating compound channels formed by regular geometrical sections of main channel and flood plain segments. The width of the main channel, the width of the total section, the depth of flow in flood plain, the total depth, channel slope and boundary roughness of main channel section and flood plain section can all be varied. The model predictions of total flow rate, shear stress distributions around the wetted perimeter, and the percentage of flow and shear force carried by the different sections were compared with published experimental data. Reasonable agreement between data and predictions was obtained.