低含沙坡面薄层水流垂线流速特征试验分析  

Experimental Analysis on Characteristics of Vertical Velocity of Overland Flow on Low Sediment Concentration

作　　者：牛梦飞 孙三祥[1,2,3] 龚正威 NIU Meng-fei;SUN San-xiang;GONG Zheng-wei(School of Environment and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou730070,China;Laboratory of Yellow River Water Environment in Gansu Province,Lanzhou Jiaotong University,Lanzhou730070,China;The Engineering Research Center of the Ministry of Education for the Comprehensive Use of Water Resources in the Cold and Dry Areas,Lanzhou Jiaotong University,Lanzhou730070,China)

机构地区：[1]兰州交通大学环境与市政工程学院,兰州730070 [2]兰州交通大学寒旱地区水资源综合利用教育部工程研究中心,兰州730070 [3]兰州交通大学甘肃省黄河水环境重点实验室,兰州730070

出　　处：《兰州交通大学学报》2022年第6期96-102,共7页Journal of Lanzhou Jiaotong University

基　　金：国家自然科学基金(51869009);。

摘　　要：为分析低含沙量条件下坡面薄层水流速分布规律.试验选用有机玻璃水槽,基于粒子图像测速(particle image velocimetry,PIV)技术根据5种水深、3种坡度、3种含沙量的垂线流速测量结果.发现含沙量对阻力系数λ,卡门常数κ都具有较大影响,水流的垂线流速分布与明渠存在较大差别.低含沙坡面薄层水流中,阻力系数λ随含沙量增大而增大,随坡度增大而增大,且受边壁影响较大.垂线分布最大流速产生在相对水深0.7~0.8的位置.在低含沙量条件下,水流在内区(底流区和主流区)的垂线流速遵循对数分布规律,其中卡门常数κ随含沙量增大而减小;最大流速约为垂线平均流速的1~1.1倍.In order to analyze the distribution of thin layer water velocity on slope under low sediment concentration conditions.A plexiglass flume was used in the experiment,and the vertical velocity was measured by using Particle Image Velocimetry(PIV)technology based on five water depths,three slopes and three sediment concentrations.The influence of sediment concentration on drag coefficientλand Karman’s constantκwas found.The drag coefficientλincreases with the increase of sediment concentration,and the maximum velocity of vertical distribution is 0.7~0.8 which is relative to water depth.Under the condition of low sediment concentration,the vertical velocity of water flow in the inner region(bottom flow region and main flow region)follows a logarithmic distribution law,in which Karman constantκdecreases with the increase of sediment concentration.The maximum velocity is about 1~1.1 times of the average vertical velocity.

关 键 词：坡面薄层水流 低含沙量 PIV 流速 卡门常数 

分 类 号：TV131.2[水利工程—水力学及河流动力学] S157.1[农业科学—土壤学]