非均匀散粒粗糙床面明渠水流流速结构PIV试验研究  

PIV Experimental Study on Flow Velocity Structure in Open Channel with Non-uniform Granular Rough Bed

作　　者：阎鑫铭 钟亮[1,2] 李国际[1] YAN Xin-ming;ZHONG Liang;LI Guo-ji(Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education,Chongqing Jiaotong University,Chongqing 400074,China;National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学水利水运工程教育部重点实验室,重庆400074 [2]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

出　　处：《水电能源科学》2024年第7期57-61,共5页Water Resources and Power

基　　金：国家自然科学基金项目(51509026)。

摘　　要：鉴于床面非均匀散粒粗糙直接影响明渠水流的流速结构问题,基于PIV水槽试验,研究了非均匀散粒粗糙床面明渠水流的流速结构,探讨了水流时均流速沿流向和沿垂线的分布规律,分析了脉动流速的象限分布特征。结果表明,梅花形排列的大尺度非均匀散粒粗糙显著影响了颗粒顶部以下的水流结构,大、小颗粒周围时均流速结构相似,颗粒大小明显影响了流动分离区形状尺度和内外层流体分界点位置;象限分析显示外层流体中,大颗粒使其上方区域Q2、Q4事件的概率减小;内层流体中Q1、Q3事件占主导,颗粒上游及大颗粒附近相比下游及小颗粒附近更易产生强紊流事件。The non-uniform particle roughness on the bed surface directly affects the velocity structure of open channel flow.Based on the PIV flume test,the flow velocity structure in open channel with non-uniform granular rough bed is investigated.The distribution rules of the time-averaged flow velocity along the flow direction and along the vertical line are discussed,and the quadrant distribution characteristics of the pulsating flow velocity are analyzed.The results show that the large-scale non-uniform scattering roughness arranged in plum blossom shape significantly affects the flow structure below the top of the particles,and the time-averaged flow structure is similar around the large and small particles,and the size of the particles significantly affects the shape scale of the flow separation zone and the location of the boundary point of the inner and outer layers of the fluid.Quadrant analysis reveals that the large particles in the outer layer of the fluid decrease the probability of the Q2 and Q4 events in the area above them;The Q1 and Q3 events of the inner fluid dominate,and strong turbulence events are more likely to occur upstream and near large particles compared to downstream and near small particles.

关 键 词：非均匀散粒粗糙床面 明渠水流 时均流速 脉动流速 象限分析 

分 类 号：TV133[水利工程—水力学及河流动力学]