| 摘要: |
| 阶梯形丁坝在航道整治中应用广泛，其回流规律与船舶通航、坝田淤积及堤岸稳定等系列问题密切相关，但目前研究很少。应用三维水流数学模型研究双级阶梯形丁坝几何尺度及来流条件对回流规律的影响，结果表明：①回流长度随一级丁坝相对长度ε1及高度ψ1、二级丁坝相对长度ε2均呈递增变化趋势，随弗劳德数Fr呈先增大后减小的变化趋势；②回流宽度随ε1，ε2和ψ1变化相对明显，而随Fr变化总体较小；③回流正、负流区宽度比沿程变化曲线总体为上凸状，负流区宽度相对较大，在靠近丁坝部位可达正流区宽度的2.5倍；④回流曲线形态与ε1，ε2和ψ1有关，ε1和ψ1主要影响回流曲线长度，ε2影响回流曲线的整体形态；⑤回流流量一般小于来流量的10%，沿程分布曲线不对称，增流区回流流量变化相对缓慢，而减流区变化相对剧烈。 |
| 关键词: 阶梯形丁坝 回流尺度 回流曲线 回流流量 |
| DOI： |
| 分类号:U617.9；TV131.2 |
| 基金项目:重庆市基础与前沿研究计划项目(cstc2017jcyAX0278)； 国家自然科学基金资助项目(51509026) |
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| Analysis on law of backflow around step-shaped spur dike |
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ZHONG Liang1,2, SUN Jianyun3, LIU Junjie3, ZHOU Xinjing4
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1.National Engineering Research Center for Inland Waterway Regulation, Chongqing Jiaotong University， Chongqing;2.Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University，Chongqing;3.Key Laboratory of Hydraulic and Waterway Engineering of the Ministry of Education, Chongqing Jiaotong University， Chongqing;4.Chongqing Information and Communication Consulting and Design Institute Co, Ltd， Chongqing
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| Abstract: |
| Step-shaped spur dike is widely used in the waterway regulation, and the law governing the backflow is closely related with the problems such as ship navigation, siltation of dam field（deposition between two groins） and embankment stability, but few studies are conducted in this field. In this research, the influence of spurs geometric scale and inflow condition on the backflow is studied by using a three dimensional mathematical model of water flow. The results show that: ①The backflow region length increases with the increasing of the relative length ε1 and relative height ψ1 of the first stage spur dike and the relative length ε2 of the second stage spur dike, and it increases first and then decreases with the Froude number Fr; ②The backflow region width changes relatively obviously with ε1,ε2 and ψ1, and changes little with Fr overall; ③The width ratio curve of the positive velocity region and the negative velocity region is overall convex, and the negative flow width is relatively large, which can be 2.5 times the width of the positive velocity region near the spur dike; ④The shape of backflow curve is related to ε1,ε2 and ψ1, and ε1 and ψ1 mainly affect the length, while ε2 affects the overall shape; ⑤The circumfluence flow is less than 10% of the discharge, and its distribution curve is asymmetric, with slow change in the flow increasing area and relatively severe change in the flow decreasing area. |
| Key words: step-shaped spur dike size of backflow region backflow curve backflow discharge |
