基于Omega涡识别方法的径流式水涡轮尾水管涡带特性  

Characterization of vortex rope in draft tube of water turbine based on Omega vortex identification method

作　　者：蒋宇浩 汤玲迪[1] JIANG Yuhao;TANG Lingdi(National Research Center of Pumps,Jiangsu University,Zhenjiang,Jiangsu 212013,China)

机构地区：[1]江苏大学国家水泵及系统工程技术研究中心,江苏镇江212013

出　　处：《排灌机械工程学报》2024年第4期395-402,共8页Journal of Drainage and Irrigation Machinery Engineering

基　　金：国家自然科学基金资助项目(52109105)。

摘　　要：为了研究水涡轮尾水管的涡带特性与Omega涡识别方法对尾水管涡带的识别效果,对比了Q准则和λ_(2)准则以及Omega涡识别方法对尾水管涡带的识别效果,并基于Omega方法和降维的Omega方法分析了不同工况下尾水管的涡带特性.结果表明:对于径流式水涡轮,通过合理调整阈值,Q准则和λ_(2)准则以及Omega涡识别方法均能识别到清晰合理的尾水管涡结构,而Omega方法阈值选取区间较小且具有不敏感性;水涡轮尾水管在小流量工况时会出现较长的涡带,不利于机械的稳定性.同时运用二维Omega涡识别方法与拟涡能指标,在不同工况下对尾水管各监测面进行定量分析,确定涡量浓度高的区域,研究尾水管的能量耗散规律.结果发现,尾水管进水口到弯管之间的区域涡量浓度最高,能量耗散最大,流态最不稳定,这可为该型式水涡轮的结构优化提供理论参考与数据支撑.In order to study the vortex rope characteristics of the water turbine draft tube and the effectiveness of the Omega vortex identification method on the vortex rope of the draft tube,the Q andλ_(2) criteria and the Omega vortex identification method on the vortex rope of the draft tube were compared,and the vortex rope characteristics of the draft tube under different operating conditions based on the Omega method and the reduced dimensional Omgea method were analyzed.The results show that for radial water turbines,the Q and λ_(2) criteria,as well as the Omega vortex identification method can identify a clear and reasonable draft tube vortex by adjusting the threshold value reasonably,while the threshold selection interval of the Omega method is small and insensitive.The draft tube of the water turbine will have a long vortex rope in the flow condition,which is not conducive to the stability of the machinery.At the same time,using the reduced-dimensional Omega vortex identification method and the proposed vortex energy index,quantitative analysis of the monitoring surface of the tailpipe under different operating conditions was conducted to determine the area of high vortex concentration,as well as studying the energy dissipation patterns in draft tube.The results show that the area between the inlet and the bend of the draft tube has the highest vortex concentration,the highest energy dissipation and the most unstable flow pattern,which can provide a basis for optimizing the structure of this type of water turbine.

关 键 词：尾水管涡带 涡识别 数值模拟 Omega方法 拟涡能 

分 类 号：S277.9[农业科学—农业水土工程]