苦草对明渠水流运动特征影响的试验  

Impact of Eel Grass on Open-channel Flow Characteristics:A Flume Study

作　　者：武迪[1,2] 赖建武 张英豪[2] 庞翠超[4] 汪德爟[1] 赖锡军[2] 

机构地区：[1]河海大学力学与材料学院,江苏南京210098 [2]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,江苏南京210008 [3]浙江逸龙建设有限公司,浙江建德311607 [4]南京水利科学研究院水工所.江苏南京210029

出　　处：《水电能源科学》2014年第2期110-113,174,共5页Water Resources and Power

基　　金：国家自然科学基金项目(41071021)

摘　　要：为了解含植被水流运动规律,以柔性植物苦草为对象,在室内水槽中开展了苦草斑块对水流时均运动特征影响的试验,观测分析了不同水流(断面平均流速分别为3、5、10cm/s)和不同植株密度(172、86、43、0株/m2)条件下含苦草水流的流速分布结构。结果表明,植被斑块对水平流速分布有影响,在斑块尾部边缘有涡的产生;由于植被的阻流作用,使得植被斑块内部流速沿程减小,斑块外围流速沿程增大;垂线流速呈S型,可划分为底边界层区、冠层次级最大流速区、冠顶过渡区及冠层上部对数流速分布区。植株密度对冠层次级最大流速区影响最为显著,密度越大,流速削减越迅速,逆转梯度越大;断面平均流速越大,植被对水流的影响越显著。To find out the law of water flow with vegetation, taking flexible plant eel grass as object, the indoor flume test was carried out to analyze the influence of eel grass on the characteristics of mean velocity. The experimental conditions were that there were three flow conditions （3cm/s, 5cm/s and 10cm/s） and three plant densities （172, 86, 43,0 plants/m2）. The flow structures were measured. The results show that there was an vortex at the junction region, velocity pattern were changed by vegetation patch; due to the resistance of eel grass, the mean flow velocities reduced inside vegetation patch and increased outside the patch; the shape of velocity was S type. The water layer was divided into 4 layers, which were bottom boundary layer, the canopy layer containing maximal secondary flow velocity, the transitional zone of canopy layer and above the canopy; the vegetation densities had the most significant influence on the secondary flow velocity maximal canopy region; the larger density the plants had, the more significant reverse flow could be observed; the larger mean velocity was, the more significant influence of the submerged plants on the flow had.

关 键 词：明渠水流 柔性植物 时均流速 逆转梯度 

分 类 号：TV143[水利工程—水力学及河流动力学]