透水丁坝对不同曲率弯道内三维水流结构影响数值模拟研究  

Numerical Simulation of Effects of Permeable Spur Dike on Three-dimensional flow Structure in Curved Channel with Different Curvatures

作　　者：谢鹏 李春光 吕岁菊 景何仿 张凤逐 XIE Peng;LI Chun-guang;LÜSui-ju;JING He-fang;ZHANG Feng-zhu(School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,Ningxia,China;School of Mathematics and Information Science,North Minzu University,Yinchuan 750021,Ningxia,China;School of Civil Engineering,North Minzu University,Yinchuan 750021,Ningxia,China)

机构地区：[1]宁夏大学土木与水利工程学院,宁夏银川750021 [2]北方民族大学数学与信息科学学院,宁夏银川750021 [3]北方民族大学土木工程学院,宁夏银川750021

出　　处：《中国农村水利水电》2024年第5期31-40,共10页China Rural Water and Hydropower

基　　金：国家自然科学基金(11861003);北方民族大学科学计算与工程应用创新团队(2022PT_S02);宁夏自然科学基金(2023AAC02050,2021AAC03208)。

摘　　要：透水丁坝相较于传统丁坝,具有更加卓越的稳定性,安全性,可靠性,因此在绿色航道推广中得到重视,研究的目的在于对比不同曲率河道内三维水流结构变化,进而为不同曲率河道治理提供依据。研究采用数值模拟与实测相结合的方式,对3种湍流模型进行比选和验证,Standard k-ε,RNG k-ε,Realizable k-ε三种湍流模型内岸模拟流速和实测流速相关性系数均低于外岸,RNG k-ε湍流模型实测流速和模拟流速相关性系数最高,最终采用RNG k-ε模型对90°和180°弯道模拟,并对三维流线,流速,床面剪切,水面线分析。结果显示丁坝下游回流区涡轴线受垂向和径向速度梯度影响出现不同程度倾斜,水流撞击2号丁坝在丁坝之间产生两个相反方向的涡,这将对透水丁坝群结构稳定形成威胁但同时也会防止大量泥沙在透水丁坝之间淤积,保证透水丁坝在使用过程中不至于丧失透水性。河道曲率增大导致强剪切层向内岸迁移,180°弯道内出现两个强剪切层,这将导致河床向阶梯型演化,对于曲率大而且狭窄的山区河道在布置透水丁坝后要对内岸侵蚀效果评估,防止强剪切层迁移对内岸构成威胁。水面线呈现内低外高的现象,且在x/L=0.48~0.5的范围里内外岸水面线差值最小,水面出现凹陷。Compared with traditional spur dike,permeable spur dike have more excellent stability,safety and reliability,so they have been valued in the promotion of green channels.The purpose of this study is to compare the changes of three-dimensional flow structure in different curvature channels,and then provide basis for river regulation with different curvature.The research uses a combination of numerical simulation and actual measurement to compare,select and verify three turbulence models:Standard k-ε,RNG k-ε,and Realizable k-ε.The correlation coefficients between simulated velocity and measured velocity in the inner bank of Standard k-ε,RNG k-ε,and Realizable k-εturbulence models are lower than those in the outer bank.The correlation coefficients between measured velocity and simulated velocity in RNG k-εturbulence model are the highest.Finally,RNG k-εturbulence model is used to simulate the 90°and 180°bend,and to analyze the three-dimensional streamline,velocity,bed shear and water surface line.The results show that the vortex axis in the downstream region of the spur dikes inclines to different degrees under the influence of vertical and radial velocity gradients.Two vortices in opposite directions are generated between the spur dikes when the current strikes No.2 spur dikes,which will threaten the structural stability of the permeable spur dikes,but at the same time prevent a large amount of sediment from depositing between the permeable spur dikes and ensure that the permeable spur dikes will not lose their permeability during use.The increase of river curvature leads to the migration of strong shear layer to the inner bank,and two strong shear layers appear in the 180°bend,which will lead to the evolution of river bed to step type.For the mountain river with large curvature and narrowness,the erosion effect of inner bank should be evaluated after arranging permeable spur dike to prevent the migration of strong shear layer from posing threat to inner bank.The water surface line is low inside and high

关 键 词：数值模拟 河道曲率 透水丁坝 三维流线 床面剪切 水面线 

分 类 号：TV854[水利工程—水利水电工程]