混流式水轮机非定常旋涡流动研究

Analysis of Unsteady Vortex Flow in Francis Hydro-Turbine

采用standard模型对某水电站水轮机进行全流道三维非定常数值仿真,研究转轮内部叶道涡对尾水涡带成形及演化的影响。通过对两种流量工况下的转轮及尾水管内部流场进行分析,探究并揭示叶道涡和尾水涡带的生长、溃灭及其相互干涉演化机制。研究结果表明,通过对水轮机内部流场的全流道仿真,能直观动态地展示出内部三维涡结构的形成及演变特征,且通过观察转轮内的叶道涡和尾水管内的尾水涡带,能清晰地展现出两者之间的相互干涉过程。因此,该数值模拟对探讨水轮机组的安全运行具有一定的参考价值。

This paper uses standard k-εmodel to conduct three-dimensional unsteady numerical simulation of the entire flow channel of a hydroelectric power plant turbine,and studies the influence of internal blade passage vortices on the formation and evolution of tailwater vortex strips.By analyzing the internal flow field of the impeller and tailwater pipe under two different flow conditions,this study explores and reveals the growth,collapse,and mutual interference evolution mechanisms of blade channel vortices and tailwater vortex bands.The research results indicate that by simulating the entire flow field inside the water turbine,the formation and evolution characteristics of the internal three-dimensional vortex structure can be intuitively and dynamically displayed.Moreover,by observing the blade passage vortex inside the impeller and the tailwater vortex strip inside the tailwater pipe,the mutual interference process between the two can be clearly displayed.Therefore,this numerical simulation has certain reference value for exploring the safe operation of water turbine units.