Abstract
Numerical simulation has been carried out for the fully developed turbulent flow of compound open channel by using Reynolds stress model. Since special attension is also paid for the boundary condition of free surface, modified boundary condition is adopted in this calculation. Moreover, the generation mechanism of cellular secondary currents is examined by calculating production terms in vorticity equation. Calculated results are compared with the experimental data available. The most characteristic feature is that the secondary currents proceed from the junction between the main channel and flood plain to the free surface. The present method can predict well not only this phenomenon but also the distributions of Reynolds stresses. Regarding to the generation of cellar secondary currents, calculated results suggest that the production term involving normal stresses plays an important role in generation of secondary currents along the free surface.
