摆动河槽水动力稳定性特征分析  

HYDRODYNAMIC INSTABILITY CHARACTERISTICS OF LAMINAR FLOW IN A MEANDERING CHANNEL WITH MOVING BOUNDARY

作　　者：白玉川[1,2] 冀自青[2] 徐海珏[1,2] Bai Yuchuan;Ji Ziqing;Xu Haijue(State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China;Department of Civil Engineering, Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学水利工程仿真与安全国家重点实验室,天津300072 [2]天津大学建筑工程学院,天津300072

出　　处：《力学学报》2017年第2期274-288,共15页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金项目(41576093;51279124;51321065);天津大学水利工程仿真与安全国家重点实验室基金(HESS-1606)资助

摘　　要：河流形态与水动力结构息息相关,形态约束水动力结构,水动力结构则通过泥沙运动进一步塑造形态,在自然界河流中形成一对辩证互馈关系.天然河流形态形式多样,大致可以分为顺直、微弯、分叉和散乱游荡几种类型,其中微弯及多个弯曲构成的河型为河流动力演化中最重要的一环.多个弯曲构成的河型可用正弦派生曲线来描述,它也是天然河流主槽与水动力结构复杂相互作用的结果.作为探讨这一过程的力学作用机理,构建摆动槽道并研究槽道摆动与其内部流动结构的互馈关系,既是流体力学研究的热点内容,也是目前河流动力过程研究的基础内容.在此重点讨论这一互馈关系前一部分,即水流对摆动边界的响应.文中建立了随体坐标系下摆动河槽与内部水流动力响应理论模型,通过给定摆动弯曲槽道的不同特征参数,研究讨论了正弦派生型摆动边界下的槽道水流动力稳定性特征,明确了弯曲槽道摆动对其内部主流及扰动水流结构的影响,确定弯曲槽道摆动波数、摆动频率对扰动流发展影响的相应参数定量关系,得到了槽道弯曲度和摆动特征对其内部水流不同尺度扰动影响的阈值选择性范围.Configuration of river is closely related with hydrodynamic structures of flows,for the shape of a channelinfluences the flow structures in it,and the flow structures also a ect the developing trend of the channel through themovement of sediment,forming a pair of dialectical interactions in the river system.The natural rivers are di erent inconfigurations,which can generally be divided into such types as straight,bending,branching and wandering.Amongthem,the bending river or the river composed of several curved channels,the result configuration of interaction betweenthe natural river and the complex hydrodynamic flow structure in it,become one of the most important types in the studyof river dynamics.As the basis of theoretical research,the establishment of model and the study on flows within a movingchannel has become the focus not only from researchers of fluid mechanics,but also from investigators of river dynamics.Therefore,this study first established a theoretic model on the flow in a meandering channel with a moving boundary by using a streamwise-transverse coordinate system.It next discussed the hydro-dynamic instability characteristics ofthe laminar flow within the sine-generated moving boundaries.Then it quantitatively analyzed the influences of variouscharacter parameters to the velocity distributions of main flow.Finally,it obtained the selective influences from thecurvature and meandering properties to the flow structure.

关 键 词：河槽摆动 槽道流动 正弦派生 水流特性 水动力稳定性特征 

分 类 号：O352[理学—流体力学]