凹岸边坡型式对急弯河道水力特性影响的数值模拟  

Numerical simulation of effect of outer bank slope types on the hydraulic characteristics in sharp bends

作　　者：李倩[1] 马黎 余明辉[1] 吴迪 龚兰强 LI Qian;MA Li;YU Minghui;WU Di;GONG Lanqiang(State Key Laboratory of Water Resources Engineering and Management,Wuhan University,Wuhan 430072,China;POWER CHINA Guiyang Engineering Corporation Limited,Guiyang 550081,China)

机构地区：[1]武汉大学水资源工程与调度全国重点实验室,湖北武汉430072 [2]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081

出　　处：《水科学进展》2023年第4期599-609,共11页Advances in Water Science

基　　金：国家自然科学基金资助项目(11972265,12372385)。

摘　　要：为研究弯道凹岸边坡型式变化对近岸水力特性的影响,以荆江石首急弯河段为研究背景建立三维水动力数学模型,模拟凹岸不同边坡型式下的弯道水流结构。研究结果表明:相同过水断面面积和水深情况下,凹岸坡度越缓,最大纵向流速越远离凹岸且接近水面,主环流尺度越小,凹岸成对出现的反向次环流位置越接近水面,凹岸深槽水流紊动越弱。对比综合坡度相同的单一岸坡,凹岸复式岸坡情况下,最大纵向流速变化不大,主环流尺度增大,次环流成对模式被改变;出口直段凹岸侧最大剪切力增大为单一岸坡的1.2倍;凹岸侧弯顶上游紊动减弱,弯顶下游紊动加剧。研究成果丰富了弯道岸坡型式对弯道水流结构影响的认识,为不同型式岸坡防护研究提供基础依据。To study the effect of the outer bank slope types on the hydraulic characteristics in sharp bends,a threedimensional hydrodynamic mathematical models was developed to simulate the flow structures under different slope types of the outer bank in the Shishou sharp bend section of the Jingjiang reach.The results show that,with the same cross-sectional area and water depth,the gentler the slope can move the maximum longitudinal velocity and the outerbank reverse secondary flow away from the outer bank and the riverbed.The gentler slope can also decrease the turbulence intensity and the main secondary flow scale.Comparing to the simple and composite riverbank with the same slope,the maximum longitudinal velocity remained almost the same but the main secondary flow scale increased and the pairing model of secondary flow were changed.The maximum shear force on the composite riverbank was 1.2 times larger than that on the simple riverbank,and thus,the composite riverbank was more vulnerable to erosion and damage.Moreover,the turbulence in the upstream of apex of bend was weakened,while in the downstream of apex of bend was intensified.The results can deepen our understanding of the effect of bank slope types on the flow structure in sharp bends,and provided a basis for the protection of different types of bank slope.

关 键 词：水力特性 边坡型式 凹岸 环流 剪切力 

分 类 号：TV147[水利工程—水力学及河流动力学]