The Simulation of the Effect of Rigid Bank Vegetation on the Main Channel Flow

A series of computational hydraulic analyses are applied for the open channels with vertical and inclined banks. During the analyses, riverbank vegetation density on inclined surface were increased to measure the flow hydrodynamic effects of the flow for both, in the inclined riverbank and main channel. The study not only covers the relationship of open channel with vegetated bank, and also proves some of the previous determined results. Additionally, the gathered results illustrate the impacts of vegetation density on riverbank to the entire channel. The longitudinal velocity, turbulence intensity (TI), turbulent kinetic energy and Reynolds stress were presented by figures, to help the outcomes of the results be more readable. The preliminary results are presented in terms of plots, based on the mean velocity along the main flow directon across the channel for ease of comparison between different configurations. The main outcome of the study despicts that, as the river bank vegetation density increases, the mean velocity in the main channel increases, while mean velocity on the river bank decreases. Reynolds stress is an essential part of shear stress in turbulent flows, and the measured Reynolds stresses show that, the stress is higher near bed of the main channel close to the vertical riverbank whereas it shifts to mid flow depths at the region close to the interface of main channel and the inclined riverbank. The turbulence intensity and the turbulence kinetic energy profiles were also showing similarity and parallel behavior with the simulated results of streamwise flow velocities and Reynolds stresses in the main channel and at the inclined riverbank. Keywords: Velocity profile, Reynolds shear stress, Vegetation, Turbulence intensity, Secondary current, Turbulent kinetic energy.