弯曲河道中水流运动的三维数值模拟  

Three-dimensional numerical simulation of flow in river bends

作　　者：许栋[1] 刘召平[2] 乾爱国[3] 白玉川[1] 

机构地区：[1]天津大学建筑工程学院,天津300072 [2]国核电力规划设计研究院,北京100094 [3]中国水利水电科学研究院水力学研究所,北京100038

出　　处：《水利学报》2010年第12期1423-1431,共9页Journal of Hydraulic Engineering

基　　金：国家重点基础研究发展计划资助项目(2007CB714101);国家自然科学基金资助项目(51009105)

摘　　要：基于雷诺方程和有限体积法建立了描述弯道水流运动的三维数学模型,用室内物理模型试验进行验证,结果表明,该模型能够较好地模拟弯道内水流流速分布以及湍流特征。随后用该模型模拟了若干典型平面形态和床面形态的弯道水流运动。模拟结果表明:弯道中浅滩和深槽相间的地形起伏加剧了断面流速分布的不均匀性,同时使得水流动力轴线更加偏向凹岸,流速的沿程变化也较平整床面更为复杂;另外,与对称型河湾(正弦派生曲线型)相比,非对称河湾(Kinoshita派生曲线型)中在两弯顶中间存在较多的低流速区,有利于泥沙落淤,而对岸流速一般较大,形成河岸的快速崩退,这能够从一个侧面解释非对称河湾向下游方向整体的快速迁移。A three-dimensional numerical model was established for bended open channel flow based on Reynolds Equations and Finite Volume Method. The model was validated with laboratory experiments in two physical models. Verification shows that the numerical model can well simulate the flow distribution and turbulent feature in river bends. Then the validated model was used as a tool to carry out numerical test on flow in river bend with various planar shapes and bed topographies. Results show that the alternative pool-bar topography in river meanders increases the unevenness of cross section flow distribution. It shifts the dynamic flow axis more close to the concave bank and complicates the streamwise fluctuation of flow components. Besides, asymmetric meanders （Kinoshita-generated） show more zones with low flow velocities compared with symmetric meanders （sine-generated）, which is favorable for sediment deposit. While the velocity near the opposite bank is relatively large causing fast bank retreat, which may interpret the fast downstream migration of asymmetric river bends.

关 键 词：弯曲河道 水流运动 三维数学模型 河湾形态 数值试验 

分 类 号：TV147[水利工程—水力学及河流动力学]