2002 Volume 46 Pages 701-706
Hydrodynamic mechanism of suspended load in open channel flows over woody plants was investigated based on the results of laboratory experiments. In the experiments, three-dimensional distributions of equilibrium sediment concentration were minutely measured in uniform flows over tree models uniformly arranged in a staggered manner. It was clarified that so-called dispersive flux plays an important role in the mass-conservation relationship of suspended load, and also that the diffusion coefficient of suspended sediment is almost proportional to the kinematic viscosity of flow. The experimental results of vertical profiles of horizontally averaged sediment concentration were accurately reproduced by a numerical model that includes an empirical model for the dispersive flux and a κ-ε turbulent flow model for the diffusion coefficient.
