| Abstract: | Due to centrifugal forces in a bend secondary currents perpendicular to the main flow are generated. Because they can be the reason for important bed forming processes such as meandering they have to be taken into account in morphodynaniic simulations. Their influence on the bed shear stress is proportional to the ratio of water depth and curve radius. The latter one is a curve parameter and is not defined in 2D digital terrain models. This paper presents a new formulation for the bed shear stress which takes into account, the influence of secondary currents in depth averaged simulations without using the curve radius. The new formulation is applied to a morphodynanuic model of the Weser estuary located in Northern Germany. Its capability to simulate the deflection of the bed shear stress in bends is shown. Because of the smoothness of the curves in the Weser no significant differences in the bed evolution can be seen in this case. |
