Numerical Study of Turbulent Flow Structure in Curved Open-Channel Flow with Flood Plains

A numerical study of turbulent flow developing in a curved open-channel flow with flood plainsis performed by using an algebraic stress model. The flow configuration of interest in this study consists of 180 degree bend with floodplains. This turbulent flow is characterized by interactive motions between pressure driven secondary flow and turbulence driven secondary flow in the curved channel. Therefore, it is indispensable to adopt anisotropic turbulence model to predict its flow preciously. Calculated results are compared with the experimental data available. In order to clarify the generation mechanism of secondary flow, production terms concerned with it, i. e. centrifugal, pressure and turbulence driven forces, are evaluated by using calculated results. As a result of this numerical study, the present method can realize the main features well, although agreement is certainly not perfect in all detail.As for the generation mechanism of secondary flow, the calculated results show that turbulence driven forces play an important role near the boundary between main channel and flood plains.