中文摘要：

本文建立非正交曲线坐标系下的三维k-ε-A。固液两相湍流模型研究弯道内的水流泥沙运动和河床冲淤变形。河床变形计算采用推移质模型和总沙模型两种处理方法。两相湍流模型在计算推移质输运时采用泥沙的横纵向速度处理推移质的强度和方向，利用泥沙垂向速度计算悬沙与床沙之间的交换通量。计算发现两相湍流模型的河床冲淤变化分布结果比单相湍流模型的结果更接近试验结果，两相湍流总沙模型计算结果中局部区域的水深比两相湍流床沙模型计算得到的水深小。床面变形以及固液两相横纵向流速分布分析比较表明，泥沙运动的横向和纵向分布对床面变形的影响起重要作用，单相湍流模型在计算弯道内的推移质运动时夸大了二次流对泥沙横向输运的作用。

英文摘要：

A three-dimensional k-ε-Ap two-phase turbulence model is solved numerically by a finite-volume method on an adaptive grid to study the water-sediment movements and bed deformation in a 180° channel bend with a movable bed. Sediment transport is solved by bed-load model and total-load model separately. Different from singlephase turbulence model, two-phase turbulence model calculates the magnitude and the direction of bed-load transport according to the longitudinal and transverse solid-phase movement, and decides the net flux across the interface of bed-load layer and suspended-load layer by the vertical solid-phase movement. Compared with measured results, two-phase flow model predicts the bed deformation better than single-phase flow model. The water depth predicted by total-load model is sometimes smaller than predicted by bed-load model. After analyzing the numerical bed deformation and solid-liquid two-phase flow velocities, it is found that the longitudinal and transverse sediment transport decide the bed deformation, and the single-phase flow model always exaggerates the effect of secondary flow on the transverse sediment transport.