Author(s): Taka-Aki Okamoto; Iehisa Nezu
Linked Author(s): Iehisa Nezu
Keywords: Organized vortices; Vegetation; Turbulent transport mechanism; Concentration; LES
Abstract: In actual rivers, a lot of aquatic plants are often observed and they have significant effects on hydrodynamic properties. In such vegetated open-channel flows, large-scale coherent vortices are generated near the vegetation edge and govern the mass and momentum exchanges between the within-canopy layer and the overcanopy layer. Therefore, in the present study, 3-D large eddy simulation (LES) was conducted to simulate the mass transport characteristics in open-channel flow with rigid vegetation elements, in which two kinds of the submergence depth were changed. The vegetation elements were calculated exactly by using the non-slip condition and fine grids without any additional drag force term. The present study revealed the relation between large-scale coherent vortices and 3-D turbulent transport mechanism in submerged vegetated open-channel flows.
Year: 2009