中文摘要：

为了研究流量和弯曲度对弯道内水流泥沙运动特性的影响,在无黏沙质床面上进行固定边壁动床弯道模型试验,测量不同弯曲度和不同流量组合条件下弯道内的水流运动特性、地形演变和输沙强度.试验表明,水流动力轴线在相邻2个弯顶之间形成过渡段,弯顶下游凸岸一侧存在局部低流速区,该区域最早出现边滩形态;流量与床面形态之间的关系是非线性的,小幅度的流量变化引起较大的床面变化;微弯河道中浅滩、深槽分布规则,当河道弯曲超过一定程度时,显著影响床面的稳定性,床面形态变得复杂;随着弯曲度的增大,河道的输沙能力有减小趋势.

英文摘要：

To investigate the influence of channel sinuousness and flow rate on characteristics of flow and sediment movement in meandering channels,experiments were carried out on the meandering channel model established on a non-coherent sandy bed with fixed sidewalls and movable bed,in which the flow field,topography and sediment transport rate were measured with combination of various sinuousness and flow rates.Test results show that the dynamic axis of flow has a transition section between two adjacent meander crests and there is a local area with low velocity downstream the meander crest near the convex bank,where sand bars first appear on the bed.There is a nonlinear relationship between flow rate and bed topography,and a small change of flow rate may lead to large bed changes.Mildly meandering channels have a regular distribution of point bars and pools and when the channel sinuousness exceeds the critical value,the bed stability will be significantly influenced with complex bed configuration.The sediment transport capability tends to shrink with the increase of channel sinuousness.