Effect of lift on bed-surface sediment size distribution in channel bend

A 3D-numerical model based on large eddy simulation and a wall model has been applied to simulate the flow field and bed shear stress in a channel bend. As the bed-surface sediment distribution is related to the shear force and lifting force near the bed, a method for calculation of the lifting force experienced by a sediment particle in a channel bend has been introduced. With some assumptions and deductions, the bed-surface sediment size distribution can be described as a function composed of shear force and lifting force in this study. By comparing with the experimental data, the function reveals that, with the effect of lifting force considered, the accuracy in predicting the bed-surface sediment size distribution can be improved by up to 41% in the transverse direction and 46% in the longitudinal direction.