受竖直旋涡影响下细沙的受力及起动分析  

Analysis of stress and incipient motion of fine sand due to vortex motion

作　　者：吴国茂[1,2] 杨胜发[1,2] 幸韵[1,2] 许旭[1,2] 

机构地区：[1]重庆交通大学国家内河航道整治工程技术研究中心,重庆400074 [2]重庆交通大学水利水运工程教育部重点实验室,重庆400074

出　　处：《泥沙研究》2013年第4期8-12,共5页Journal of Sediment Research

基　　金：国家"十二五"科技支撑计划(2011BAB09B01);重庆市教委科学技术研究项目(KJ120406)

摘　　要：丁坝的研究一直是河流整治研究的重要问题。由于丁坝的水流分离现象,在丁坝下游产生旋涡,而这种旋涡不断流向回流区,其水流极其复杂。本文通过简化旋涡的内部结构来进行分析,得到涡内部的压强分布从外到里减小,在中心处最小。利用压力差和隐蔽度对泥沙进行受力分析,得出了泥沙上举力和涡轴力受力分布,并对上举力和涡轴力进行比较,得出离涡心越近,上举力与涡轴力的比值越大,最后在此基础上得出泥沙的起动流速公式,分析得到泥沙离涡心越近所需的起动流速越小。The research of spur dikes is an important problem in the study of river regulation.Downstream vortexes below a spur dike due to flow separation are produced.The vortexes flow to the backflow region continually and the flow phenomenon is extremely complex.The result of study by simplifying the internal structure of a vortex shows that the internal pressure becomes smaller from outside to inside and the pressure is minimum in the center of the vortex.Making use of pressure difference and hidden degree,the uplift and vortex axis force stress distribution is obtained.Then,compared the uplift and the vortex axis force,the former is greater when it is close to the vortex core.Finally,the equation of incipient velocity of sediment is obtained,which shows the closer to the vortex core,the smaller the incipient velocity.

关 键 词：竖直旋涡 隐蔽度 上举力 涡轴力 起动流速 

分 类 号：TV142.1[水利工程—水力学及河流动力学]