淹没刚性植被明渠紊流沿程流动特性差异  

A study on the differences of turbulent flow properties along the open channel with submerged rigid vegetation

作　　者：陈月君 赵连军[1] 王瑶 朱子春 谈广鸣[2] 王明阳 CHEN Yuejun;ZHAO Lianjun;WANG Yao;ZHU Zichun;TAN Guangming;WANG Mingyang(Key Laboratory of Lower Yellow River Channel and Estuary Regulation,Ministry of Water Resources,Yellow River Institute of Hydraulic Research,Zhengzhou 450003,China;State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;Quality and Safety Inspection Service Center for Construction Project of Xiong′an New Area,Baoding 071700,China;School of Water Conservancy and Transportation,Zhengzhou University,Zhengzhou 450001,China;China Institute of Water Resources and Hydropower Research,Beijing 100044,China)

机构地区：[1]黄河水利委员会黄河水利科学研究院水利部黄河下游河道与河口治理重点实验室,河南郑州450003 [2]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [3]雄安新区建设工程质量安全检测服务中心,河北保定071700 [4]郑州大学水利与交通学院,河南郑州450001 [5]中国水利水电科学研究院,北京100044

出　　处：《水科学进展》2024年第2期256-264,共9页Advances in Water Science

基　　金：国家重点研发计划资助项目(2023YFC3206201);国家自然科学基金资助项目(U2243219)。

摘　　要：淹没刚性植被通过改变水流结构,造成时均流速、紊动强度、雷诺应力等水力参数垂线分布不均匀和沿程差异化。采用声学多普勒测速仪(ADV)测量3种淹没度(3.0、4.0、5.0)下的流速,结合统计学方法,系统分析植被段内及其上、下游过渡段流速和紊动特性差异。结果表明:植被显著增强了水流紊动,且紊动特性取值与淹没度正相关;植被段内流速差异在低淹没度下的植被层内和高淹没度下的自由流动层内更加显著,而紊动特性沿程增强,且垂线分布具有相似性,最大值点位于冠层顶部附近;当淹没度满足KH涡的形成和发展条件时,随淹没度的增大,植被段内紊动特性垂线分布出现转折点(临近此点梯度急剧减小并趋于0)的断面数量增多,经验证,在充分发展的紊流区此点可作为KH涡的上边界点。Submerged rigid vegetation causes uneven vertical distribution and streamwise differences of hydraulic parameters such as time-averaged flow velocity,turbulence intensity,and Reynolds stress by altering the flow structure.ADV is adopted to measure the flow velocity under three submergence ratios of 3.0,4.0,and 5.0,combined with statistical methods,the differences in velocity and turbulence characteristics within the vegetation section and its upstream and downstream transition sections are systematically analyzed.The results show that vegetation significantly enhances water flow turbulence,and the values of turbulence characteristics are positively correlated with submergence ratios.Within the vegetation segment,the differences in velocity are more significant in the two vertical zones:one is the vegetation layer under low submergence and the other is the free flow layer under high submergence.Furthermore,the values of turbulence characteristics are enhanced along the path,and the vertical distribution has similarity,with the location of maximum point is near the top of the canopy.When the submergence ratio meets the formation and development conditions of KH vortices,the turning point appears gradually in the vertical distribution curves of turbulent characteristics within the vegetation segment,near which the gradient value sharply decreases and approaches 0.In addition,the number of cross sections with turning points increases with submergence ratios increasing.It is verified that this point can serve as the upper boundary point of KH vortices in the fully developed turbulent flow region.

关 键 词：刚性植被 淹没度 时均流速 紊动特性 声学多普勒测速仪 

分 类 号：TV131.2[水利工程—水力学及河流动力学]