| 引用本文: | 李晓超,乔超亚,谢敏萍,等.掺气坎σ值对阶梯式溢洪道的性能影响研究[J].灌溉排水学报,0,():-. |
| LI Xiaochao,QIAO Chaoya,XIE Minping,et al.掺气坎σ值对阶梯式溢洪道的性能影响研究[J].灌溉排水学报,0,():-. |
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| 掺气坎σ值对阶梯式溢洪道的性能影响研究 |
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李晓超1, 乔超亚2, 谢敏萍3, 肖广磊3, 秦蓉3, 张浩4
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1.中国华水水电开发有限公司;2.中国长江电力股份有限公司;3.华北水利水电大学 能源与动力工程学院;4.河南天池抽水蓄能有限公司
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| 摘要: |
| 【目的】进一步探索掺气坎对阶梯溢洪道的水力性能影响研究。【方法】提出了高距比值，并通过数值模拟软件，针对值取1/3、1/2、2/3下，分别取0.6m、0.9m、1.2m的9种阶梯溢洪道方案进行了模拟仿真，对各方案下阶梯溢洪道的水面线、速度矢量、掺气浓度、消能率进行了判断分析。【结果】发现掺气坎值对阶梯溢洪道性能有显著影响，掺气坎位置越靠近下游，阶梯溢洪道消能率越高且越稳定，受σ值的影响越小；σ值越小，掺气坎前空腔越多；σ值越大，掺气坎后空腔越多；掺气坎后空腔有利于提升台阶竖直面水流掺气浓度值；掺气坎位置越靠近下游，掺气浓度越高；掺气坎越高，掺气浓度越高。【结论】通过对掺气坎不同σ值方案下的阶梯溢洪道性能分析，结合数值模拟结果，发现掺气坎在同一σ值下，位置越靠近下游，水流流态越平顺、掺气效果越稳定、消能率越高；掺气坎在同一位置下，σ值越大，阶梯溢洪道的水流流态越平顺、掺气效果越好，但消能率却并非在最大σ值下最优，而是存在一个σ极值，且随着掺气坎向下游移动有减小趋势。 |
| 关键词: 阶梯溢洪道；掺气坎；消能率；数值模拟 |
| DOI： |
| 分类号:TV651.1 |
| 基金项目: |
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| Study on the Influence of Aeration Threshold σ Value on the Performance of Stepped Spillway |
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LI Xiaochao1, QIAO Chaoya2, XIE Minping3, XIAO Guanglei3, QIN Rong3, ZHANG Hao4
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1.China Water Hydropower Development Co.,Ltd;2.China Yangtze Power Co.,Ltd;3.North China University of Water Resources and Electric Power;4.Henan Tianchi Pumped Storage Power Co Ltd
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| Abstract: |
| 【Background】As we all know, in hydropower stations and other water conservancy hubs, the primary task is often not power generation, but flood control. Since the hydropower resources in China are mainly concentrated in the western region, high water head, large discharge and narrow river valley are the typical characteristics of many hydropower projects in the west. In order to ensure the safety of the mass lives and property of the people, the key control factor of the project construction is how to ensure a smooth discharge of energy dissipation. As one of the flood discharge buildings, the stepped spillway has been rapidly developed and widely used because of its high energy dissipation rate and the ability to effectively reduce the size of the downstream damping pool and other facilities. However, the stepped spillway is easy to be damaged by cavitation erosion under large single-width flow. Therefore, experts at home and abroad have carried out a lot of research on stepped spillway. Through THE ANALYSIS OF THE FLOW PATTERNS of the stepped spillway, the experts PUT forward three flow patterns: "DROP flow", "transition flow" and "sliding flow", and through further test and analysis, it is found that the energy dissipation rate of the stepped spillway is related to the dam slope of the step, the order, the form and the critical water depth. Some experts have improved the hydraulic performance of the stepped spillway through continuous improvement of the step form. Integrated predecessors' experience, the current application of the stepped spillway is combination ladder way more, in recent years, in numerous combination stepped spillway, aeration candy type stepped spillway with its superior performance, construction is convenient, the characteristics of the spillway can effectively solve the ladder to the cavitation erosion damage, is becoming the new spillway. At present, experts and scholars have little research on the height and position direction of the aerator. 【Objective】In this paper, the hydraulic performance of the stepped spillway is studied and analyzed according to different values of the aerator, that is, the aerator is at different positions of the steps and at different heights of the aerator, so as to further explore its internal rules and improve its performance. 【Method】Is proposed in this paper from higher than the sigma value, and through the numerical simulation software, in view of the different value of 9 kinds of stepped spillway scheme has carried on the simulation, through to the next step of the program line, and the velocity vector, the surface of the spillway, the dissipation of the aeration consistency judgment analysis, 【Result】found the aerated candy sigma value has a significant influence on stepped spillway performance.【Conclusion】The closer the aerator is to the downstream, the higher and more stable the energy dissipation rate of the stepped spillway is, and the less affected by σ value is. The smaller the value of σ, the more cavities in front of the aerator. The larger the value of σ, the more cavities behind the aerator. The aeration concentration value of the air flow in the vertical plane of the lifting step and the advantage of the cavity after the aeration barrier; The closer the aerator is to the downstream, the higher the aerator concentration is. The higher the aeration threshold, the higher the aeration concentration. |
| Key words: Stepped spillway；The aerated candy；Energy dissipation rate；Numerical simulation |
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