【摘要】 本文使用非结构化网格对流动区域进行离散,这种方法保证了计算网格形态良好,从而提高了计算精度。在对影响卡门涡频率敏感的分离位置计算中,使用了差分方法进行紊流边界层计算,确定分离位置。通过卡门涡频率预估模型对岩滩水电站水轮机固定导叶和活动导叶后的卡门涡频率进行了计算,计算结果与实测结果一致。本文建立的水轮机固定导叶和活动导叶后卡门涡频率预估模型,可在设计阶段进行叶片绕流卡门涡频率的预估。更多还原

【Abstract】 In the flow computation, the Unstructured Mesh was used to fit complex geometry of the computation domain, which could assure the mesh’s good shape, accordingly, could improve the result accuracy. In the computation, the shedding frequency was susceptibly depending on the separation point, which was precisely calculated in the numerical simulation of boundary layer by applying Difference Method. As a case study, a detailed flow analysis and shedding frequency calculation were carried out for different operating range under different heads for the turbine of the Yantan Hydropower Station. The results showed that calculated shedding frequency agreed well with the test data. The shedding frequency computation model built in this paper can be used to predict the shedding frequency of the Karman vortices for designing hydraulic turbines.更多还原