Flow and Bed Topography in Channel Bends

Uniform flow in river bends of rectangular or arbitrary cross section has been calculated by the slip velocity method and the results are compared with experiments. It is concluded that the helical motion introduced by the channel curvature may be fairly well described. The results are then applied to the more complex problem of flow in a river bend with movable bed. Next, the problem of flow in a meandering channel with fixed side walls has been investigated, using a special system of curvilinear coordinates. The solution of the linearized flow equations yields a method for calculation of the distribution of the bed shear stress. In the first approximation the large-scale bottom geometry is calculated by considering the lateral sediment balance. The helical flow will move the sediment particles towards the curvature center, while the transverse slope of the bed will give a movement in the opposite direction.