中文摘要：

利用数学模型,采用带旋流修正的紊流模型,同时借助VOF方法描述自由表面,对6个连续反向弯道中的水流运动特点进行了数值计算,分析了连续弯道中的主流线分布,不同来流情况下的纵向水面流速变化以及横向环流在连续弯道中的发展过程。结果表明,在连续弯道中,高流速区均出现在弯顶前凸岸一侧;连续弯道两个反向弯段的横向环流也是反向的,下一个弯段的环流发展受到上一个弯段环流明显的抑制作用;随着上游来流量的增大,弯道中最大纵向流速的位置由弯顶前凸岸处向弯顶下移,顶冲点下移,纵向流速沿弯道宽度方向的分布趋于均匀,水流＂走直＂的趋势明显。

英文摘要：

A 3D numerical model, including the realizable eddy viscosity model for the turbulence and the VOF method for the free water surface, is employed to investigate the complex flows in a model river with successive bends. The numerical results show that high velocity area is close to the convex bank before the turning point of the bends. The secondary circulation in two reverse successive bends reverses its direction and its intensity in the lower bend is weakened by the upper bend. With an increasing discharge, the longitudinal velocity shows a tendency to become uniform in the lateral direction.