环流修正模型对连续弯道水流模拟的适用性分析  

Suitability of simulating flow in meandering channel by modified depth-averaged model

作　　者：秦翠翠[1] 邵学军[1] 周建银[1] 周刚[2] 肖毅[3] 

机构地区：[1]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [2]中国环境科学研究院国家环境保护河口与海岸带环境重点实验室,北京100084 [3]重庆交通大学国家内河航道整治工程技术研究中心,重庆400074

出　　处：《清华大学学报（自然科学版）》2016年第12期1264-1270,1277,共8页Journal of Tsinghua University(Science and Technology)

基　　金：国家自然科学基金资助项目(51409027;51109194);长江科学院开放研究基金资助项目(CKWV2012303/KY)

摘　　要：现有的环流修正模型多通过对单弯道或曲率较小的连续弯道的水流模拟来验证,其对曲率较大的连续弯道或天然河道水流模拟的适用性有待进一步分析。为解决这一问题,该文将修正模型应用于曲率较大及与天然河道平面形态相近的变曲率连续弯道的水流模拟中,来检验修正模型的适用性并分析修正项的作用。结果表明:修正模型模拟的水深略高于非修正模型,纵向水深平均流速与实测值更接近,在壁面附近尤为明显。通过对修正项的分析得出,修正项的量级与黏性项量级相当,其作用不可忽略,且在壁面附近对流速的修正作用最明显。通过分析表明,该文所采用的修正模型对曲率较大的连续弯道的水流模拟具有一定的适用性,对壁面附近流速模拟精度的提高使得本文修正模型更适用于弯道横向演变的模拟研究。Secondary flow plays an important role in bend flow simulations. There are numerous models in the literature that consider the secondary flow effects. However, these models have generally been verified through simulating flows in a single bend or meandering channels with weak curvature. These models may not he applicable to channels with strong curvature or natural meandering rivers. This paper presents a model which is applied to two laboratory channel bends, one with strong curvature and the other with curvature varying like a natural river. The results show that the modified model predicts a higher water surface and improves the velocity simulation results. The dispersion terms have the same order of magnitude as the viscous stress term and should not be neglected in flow simulations of meandering channels with strong curvature. In addition, the dispersion term plays an important role in improving the velocity simulation results near the wall. Thus, this model is applicable to flow simulations in meandering channels with similar configurations and is more suitable for simulating the lateral evolution of meandering rivers.

关 键 词：弯道环流 连续弯道 修正项 二维数学模型 

分 类 号：TV143.2[水利工程—水力学及河流动力学]