漂浮植被作用下河道水流流速沿程变化研究  

Predictive Method for the Evolution of Flow Velocity in an Open Channel with a Floating Vegetation

作　　者：单钰淇 桂子钦 曹辉[1] 任玉峰[1] 刘超[3] SHAN Yuqi;GUI Ziqin;CAO Hui;REN Yufeng;LIU Chao(Hubei Key Laboratory of Intelligent Yangtze and Hydroelectric Science,China Yangtze Power Co.,Ltd.,Yichang 443000,China;Institute for Disaster Management and Reconstruction,Sichuan University,Chengdu 610065,China;State Key Laboratory of Hydraulic and Mountain River Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]智慧长江与水电科学湖北省重点实验室(中国长江电力股份有限公司),湖北宜昌443000 [2]四川大学灾后重建与管理学院,四川成都610065 [3]四川大学山区河流保护与治理全国重点实验室,四川成都610065

出　　处：《工程科学与技术》2025年第1期21-28,共8页Advanced Engineering Sciences

基　　金：国家重点研发计划政府间国际科技创新合作重点专项(2022YFE0136700);国家自然科学基金资助项目(52179074,52279072);四川省科技计划资助项目(2022NSFSC0969);智慧长江与水电科学湖北省重点实验室开放研究基金项目(ZH21020001)。

摘　　要：漂浮植被常见于明渠河道水面。漂浮植被可改变河道水流流速,影响植被吸收营养物效率。本文将漂浮植被作用下的明渠河道沿垂向划分为漂浮植被区和无植被区。在植被阻力作用下,水流进入漂浮植被区后不断调整,流速不断降低,直至水流充分发展后,水流流速稳定不变。将漂浮植被区的水流调整长度定义为漂浮植被前端至水流充分发展处的长度。基于指数衰减函数,建立了漂浮植被区水流流速沿程分布预测方法;在此基础上,联立水流连续方程,提出了漂浮植被下方无植被区的水流流速沿程分布预测方法。所提计算模型结构简单、易于应用,所有输入参数可由水流和植被条件确定。采用已有的试验资料检验计算模型,发现本文模型能够准确预测漂浮植被区和无植被区的流速沿程分布。研究可为河道水环境治理与生态修复提供技术支撑。Floating canopies are often distributed in open channels,altering the flow velocity evolution and affecting the nutrient removal efficiency of floating vegetation.The flow in an open channel with a floating vegetation canopy is vertically divided into the vegetated region and the bare channel.As the flow enters a floating canopy,the flow along the canopy’s leading edge adjusts,and the in-canopy velocity continuously diminishes over the interior adjustment distance,X_(D),due to vegetation drag.Beyond X_(D)(x>X_(D)),the flow becomes fully developed,and the velocity remains constant.Inside a floating canopy,the interior adjustment distance,X_(D),is defined as the distance from the canopy’s leading edge to the position where the flow is fully developed.A model based on exponential decay and the flow continuity equation is proposed to predict the longitudinal profiles of streamwise velocities within and below a floating canopy.The proposed model does not include a calibration parameter,and all input parameters can be obtained from flow and vegetation conditions,which is advantageous for its application.Twelve groups of experimental data from various sources are utilized to verify the proposed model.The model accurately predicts the velocity evolution within and below the floating canopy of vegetation.This study proposes a predictive model for the longitudinal profiles of streamwise velocities in an open channel with a floating canopy,providing a theoretical basis for river ecological restoration and water resource management.

关 键 词：漂浮植被 流速分布 预测模型 营养物去除 

分 类 号：TV133[水利工程—水力学及河流动力学] TV131