摘要
采用仿真草皮和三棱柱砖块模拟生态护岸,通过在室内非对称式梯形水槽内设置变流量和变底坡工况,对不同护岸型式下的梯形河道的糙率、流速分布和紊动强度进行了研究.结果表明:河道综合糙率随水深的增加而增大,改变流量或底坡对护岸糙率值影响不明显;主槽和斜边坡上,纵向流速的垂向分布均符合对数分布规律,横向分布呈现沿主槽向边滩逐渐减小的趋势,流速的横向梯度受河道底坡和护岸型式的影响较大;在主槽区,紊动强度沿垂向线性递减,而边坡区则先增大后减小;紊动能沿横向先增大后减小,在主槽与边坡交界区达到最大,表明交界区的紊动交换最强.
Artificial turf and triangular prism brick were adopted to imitate ecological revetment,and the roughness coefficient,velocity distribution and turbulence structure of trapezoidal open channel flow with revetment were investigated based on the experiments conducted in an asymmetric trapezoidal flume with different flow rate and bed slope.The results show that,the composite roughness increases with increase of flow depth,while variation of flow rate or bed slope has no obvious effect on roughness coefficient.The vertical distribution of streamwise velocity conforms to the logarithmic profile,with lager values found in the main channel,and the different sets of bed slope and revetment type exert an obvious effect on the lateral gradient of depth averaged streamwise velocity.In the main channel,the turbulence intensity monotonically decreases vertically from the channel bed,while in the side slope,it increases firstly near the channel bed and then decreases.In the lateral direction,the turbulent kinetic energy increases firstly along the transversal axis,reaches a maximum value at the interface between the side slope and the main channel,then decreases along the transversal axis,indicating that the turbulent exchange is strongest near the interface.
作者
李仟
曾玉红
LI Qian;ZENG Yuhong(State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第2期61-66,共6页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51879197,51622905)
广东省水利科技创新项目(2017-05,2016-03).
关键词
梯形河道
生态护岸
糙率系数
流速分布
紊动特性
trapezoidal open channel
ecological revetment
roughness coefficient
velocity distribution
turbulence structure
