基于大涡模型的床面形态与水流相互作用过程模拟研究

刘汛; 宗全利; 刘贞姬; 苏军

基于大涡模型的床面形态与水流相互作用过程模拟研究

1. 石河子大学水利建筑工程学院;
2. 青岛农业大学资源与环境学院;
3. 石河子市水利工程管理服务中心

基金项目:

国家自然科学基金项目(12162030)

山东省自然科学基金项目(ZR2021ME167)

详细信息

作者简介:
刘汛(1996—),男,宁夏银川人,硕士研究生,主要从事河流动力学方面研究

通讯作者:
宗全利(1979—),男,山东临朐人,博士,教授,博士生导师,主要从事河流动力学方面研究

中图分类号: TV147
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出版历程
- 收稿日期: 2023-08-16
- 刊出日期: 2024-04-27

Simulation on the interactions between bed morphology and water flow based on the large eddy model

1. College of Water Conservancy and Architectural Engineering, Shihezi University;
2. School of Resources and Environment, Qingdao Agricultural University;
3. Shihezi Water Conservancy Engineering Management Service Center

摘要

摘要: 为判断动床弯道中二次流和涡结构模型的模拟精度，基于Barbhuiya的90°水平弯道冲刷水槽试验，比较了大涡模型（LES）和RNG k-ε模型对弯道冲淤过程中床面形态模拟的精确程度，发现LES模型结果更加精确。基于LES模型模拟结果，通过使用Q准则识别二次流产生的底部涡结构，分析了涡结构对床面冲刷淤积的定量影响。结果表明：在清水冲刷动床弯道的过程中，Q值介于30～50之间时底部涡趋于稳定存在，Q值大于50时会明显影响床面冲淤；强大稳定的涡结构会使床面形态逐渐稳定，床面冲刷和淤积速率趋于一个定值，床面冲刷和淤积速率不超过2×10^-6m/s。进一步分析弯道内剪切流速与床面形态的关系，发现弯道内存在两类高剪切流速区域，当第一类区域剪切流速值大于第二类时，床面会出现深度大于0.10 m的明显冲刷坑。研究结果可为弯道中冲淤平衡和床面形态模拟提供参考。
- 大涡模型 /
- 弯道模型 /
- 床面形态 /
- 动床模拟 /
- RNG k-ε模型
Abstract: To investigate the model simulation accuracy of secondary flow and eddy structure in dynamic bed bends, the simulation accuracy of bed morphology during scouring and siltation process in bends by the large eddy model（LES） and the RNG k-ε model was verified by the scour flume experiments of a 90° horizontal bend by Barbhuiya, and the results of the LES model were found to be more accurate. Based on the simulation results of the LES model, the bottom vortex structure generated by secondary flow was identified by the Q criterion, according to which the quantitative effect of vortex structure on bed scouring and siltation was analyzed. The results show that in the process of clear water scouring the dynamic bed bend, the bottom vortex tends to be stable when the Q value is between 30-50, and becomes strong enough to affect the bed scouring and siltation when Q＞50, because a strong and stable vortex structure can stabilize the bed morphology, leading to a constant bed scouring and siltation rate, which changes within 2×10^-6 m/s. According to the analysis of the relationship between the shear flow velocity in the bend and the bed morphology, there are two types of high shear flow velocity areas in the bend, when the shear velocity value of the first type area is larger than that of the second type, obvious scouring pits with a depth greater than 0.10 m will appear on the bed surface. The results of this study can be used as a reference for the simulation of siltation equilibrium and bed morphology in the bends.
- large eddy model /
- bend model /
- bed morphology /
- dynamic bed simulation /
- RNG k-ε model

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参考文献(23)

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