Numerical investigation of flow through vegetated multi-stage compound channel

This paper addresses the problem of the renormalization group k-ɛ turbulence modeling of a vegetated multi-stage compound channel. Results from Micro acoustic Doppler velocimeter (ADV) tests are used with time and spatial averaging (double-averaging method) in the analysis of the flow field and the characterization. Comparisons of the mean velocity, the Reynolds stress, and the turbulent energy distribution show the validity of the computational method. The mean velocity profile sees an obvious deceleration in the terraces because of vegetation. Secondary flow exists mainly at the junction of the main channel and the vegetation region on the first terrace. The bed shear stress in the main channel is much greater than that in the terraces. The difference of the bed shear stress between two terraces is insignificant, and the presence of vegetation can effectively reduce the bed shear stress.