Abstract
It is recognized that the secondary current of the first kind and the outer-bank cell generated at open channel bends affect not only bank erosion but also lateral velocity distributions. These phenomena have three-dimensional (3D) flow structures, therefore, 3D model is basically needed to predict the phenomena. However, 3D computation is usually expensive in practical, thus two-dimensional (2D) model is recognized as an efficient tool for practical purposes. Nevertheless, comparisons between 2D and 3D results not well made in curved open channel flow. In this study, we carried out detailed comparison(are ) s between 2D and3D(a ) results in both mild and sharp curved open channel flows under a fixed flat bed as well as a deformed bed conditions. The numerical results showed that the depth-averaged profile on a flat bed by 2D model is more different than 3D results in case of a mild bend than the case of a sharp bend. If the bed is deformed, the difference of 2D and 3D results becomes smaller.
