Abstract
The κ-ε turbulence model has been developed at present to predict reasonably turbulent structure over dunes in open-channel flows. In closed duct flows and boundary layers, the turbulent structure is reproducted reasonably by relevant models. However, Nezu and Nakagawa (1987) found that the standard κ-ε turbulence model can not predict reasonably turbulent structure in open-channel flows, because the turbulence near the surface is more depressed than in the closed duct flows. Therefore, in the present study, the standard κ-ε model with generalized coordinate in which the effect of surface is taken into account is used to predict turbulent structure in open-channel flows over dunes. Mean velocity, turbulence characteristics and the effect of surface in open-channel flows over dunes were discussed.
