This study develops a quasi-3D mobile-bed model for investigating the sediment transport behaviors in channel bends. Following the vertical and horizontal splitting concept (VHS), the shallow water flow governing equations were splitted into two parts including the depthaveraged two-dimensional and velocity defect equations in the vertical direction. The former equation was converted into orthogonal curvilinear coordinate system; the latter was derived as the form of sigma coordinate. Incorporated with continuity equation, the three-dimensional velocity field can therefore be solved. Sediment transport governing equations include mass transport equation, active-layer continuity equation, and bed-layer continuity equation for bed-load computation based on the near bed velocity field. The experimental data collected including depth and bed variation in mildly curved and sharply curved channel are used to verify the applicability of the proposed model in bend-flow simulation. Comparing the 2D depth-averaged model, the proposal quasi-3D model demonstrates its outstanding performance in the bed-load simulation of channel bends.
|Original language||Chinese (Traditional)|
|Number of pages||12|
|Journal||Taiwan Water Conservancy|
|State||Published - 2015|