Author(s): Shuang Gao; Tadaharu Ishikawa
Linked Author(s):
Keywords: Numerical simulation; Riparian vegetation; Flow adjustment; Shear layer development; Horizontal coherent vortices
Abstract: Quasi-3D model and SDS (sub-depth scale) turbulence model are combined to simulate the flow diverging and the horizontal shear layer development along the interface of riparian vegetation. Production terms in SDS model were modified based on previous experiments that measured the turbulence intensity in open channel flow and flow through model vegetation zone (cylinder arrays). Numerical simulations were conducted for two flume experiments with a rectangular model vegetation zone along channel bank. Good agreements were obtained for the transverse and stream-wise profiles of velocity and turbulence components in the developing shear layer containing horizontal coherent vortices. The vortex generated secondary circulation was also reproduced qualitatively. Furthermore, the simulation results suggested the secondary circulation is strong enough to influence the vertical movement of suspended sediment and the dynamic 3D flow characteristics might have significant effect on sediment deposition.
Year: 2013