基于流动稳定性理论的黄河游荡河型产生条件  

Formation Conditions of Wandering Reaches of the Yellow River Based on Flow Stability Theory

作　　者：李占松 LI Zhan-song(College of Water Conservancy and Civil Engineering,Zhengzhou University,Zhengzhou 450001,China)

机构地区：[1]郑州大学水利与土木工程学院,河南郑州450001

出　　处：《水电能源科学》2022年第12期50-53,共4页Water Resources and Power

摘　　要：黄河多流路的游荡分汊河型从理论上可归结为是单流路顺直及弯曲河型失稳的结果。鉴于雷诺方程、泥沙输运方程与N-S方程同属于对流扩散方程,具有类似的型式,因此层流失稳可转化为湍流的条件,也可推广为单流路顺直及弯曲河型失稳转化为多流路游荡分汊河型的条件。分析结果表明,黄河下游可近似为宽浅冲积河道,对应某一特征粒径及含沙浓度,存在一水深临界值。当实际水深大于该水深临界值时,水流失稳,单流路顺直及弯曲河型转化为多流路的游荡分汊河型;反之,则水流稳定。In theory,the wandering and branching reach of the Yellow River with multiple flow paths is the result of the instability of the straight and curved reach with a single flow path.Reynolds equation,sediment transport equation,and N-S equation,which have similar forms,belong to the convection diffusion equation.Therefore,the instability condition for the laminar flow transforming into the turbulence can also be extended as the instability condition for the straight and curved reach with a single flow path transforming into the wandering and branching reach with multiple flow paths.The analysis results show that the lower reaches of the Yellow River can be approximately regarded as a wide and shallow alluvial channel,and therein has a critical value of the water depth corresponding to a certain characteristic particle size and sediment concentration.When the actual water depth is greater than the critical value,the flow is unstable and the straight and curved reach with a single flow path will be transformed into the wandering and branching reach with multiple flow paths.Otherwise,the flow is stable.

关 键 词：黄河 游荡型 流动稳定性 湍动雷诺数 

分 类 号：TV147[水利工程—水力学及河流动力学]