Vertical profiles of streamwise velocity inside nonand vegetated meandering compound channel

Abstract

Advances in computer capabilities have increased the interest of using more complex simulation model into solving the Navier Stokes equation in open channel. Computational fluid dynamics using Large Eddy Simulation model were used to simulate the vegetation presence on floodplain along main channel inside meandering compound channel. Simulations were done for two different relative depths for non- and vegetated cases. The measured and predicted inbank streamwise velocitiy were compared at bend apex of the compound channel for validation. Presence of vegetation significantly reduces the velocity in the area near the vegetated main-channel and floodplain interface also in the area protected from the upstream flows. The numerical result shows that the flows inside the main channel were greatly affected by the vegetation especially for low relative depth. Interaction between streamwise velocity of overbank and inbank becomes more complex thus highly turbulence in the area near the vegetation.