低坝工程对弯道水流特性影响试验和数值模拟  

Experimental and numerical simulation study on the influence of low dam engineering on the water flow characteristics of bends

作　　者：牛志攀 杨航[1] 赵惟扬 孟楚轲 龙屹 NIU Zhipan;YANG Hang;ZHAO Weiyang;MENG Chuke;LONG Yi(Institution of Disaster Management and Reconstruction,Sichuan University,Chengdu 610207,China;State Key Laboratory of Hydraulics and Mountain River Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学灾后重建与管理学院,四川成都610207 [2]四川大学水力学与山区河流开发重点实验室,四川成都610065

出　　处：《水科学进展》2023年第4期562-571,共10页Advances in Water Science

基　　金：国家重点研发计划资助项目(2019YFC1510704);四川省科技计划资助项目(2023NSFSC0949)。

摘　　要：弯道河流运动复杂,威胁河岸及周边设施安全。研究低坝对弯道水流特性的影响,可探讨低坝对于弯道水流灾害风险防治的作用。采用模型试验与数值模拟相结合的研究手段,参考岷江某支流部分弯道河段进行实体和数值建模,对比分析了建坝前后流速、凹岸水位、断面横比降等水流特征变化。研究结果表明:低坝有效减小了弯道水面横比降和流速,同时降低了凹岸水面高度;在模型试验条件下(河床比降在0~52.5‰之间),建坝后相比于建坝前,流速、凹岸水面高度和弯道横比降降幅分别在6.7%~31.8%、3.7%~26.5%和9.8%~34.8%范围内,并给出了建坝后弯道横比降的预测公式。研究结果为弯道河流的洪涝灾害防治提供了科学参考。The movement of curvilinear streams manifests complexity and imperils the safety of the surrounding riverbanks and related facilities.By studying the influence of low dams on the water flow characteristics of bends while exploring the role of low dams in combating risks associated with hydrological disasters in bends.By combining experimental methods and numerical simulations,this study carries out both physical and numerical modeling using selected bends of a tributary to the Minjiang River as reference points.The paper compares and analyzes changes in flow characteristics,such as the flow velocity,concave bank water level,and cross-sectional gradient,before and after dam construction.The study′s findings show that a low dam effectively reduces the water surface gradient and flow velocity of the bend and simultaneously decreases the concave bank′s water surface height.Under the model test conditions(the gradient J of the riverbed ranges from 0 to 52.5‰),compared with before the dam was built,the flow velocity,the water surface height of the concave bank,and the transverse ratio of the curve decreased in ranges of 6.7%—31.8%,3.7%—26.5%,and 9.8%—34.8%,respectively.A prediction formula of the curve transverse gradient after the dam is built is given.These results offer a scientific basis for the flood hazard prevention and control of curved rivers.

关 键 词：低坝 水流特性 河床比降 弯道水流 横比降 

分 类 号：TV135.2[水利工程—水力学及河流动力学]