来流攻角变化对动叶栅内流动影响的数值分析

Numerical Analysis of Influence of AOA Variation on Rotating Cascade Internal Flow of Steam Turbine

以某300MW汽轮机高压反动级为研究对象,采用FLUENT软件中标准k-ω湍流模型,应用SIMPLEC算法对不同攻角下叶栅内部的流动进行数值模拟,分析了不同攻角时通道内二次流的产生、发展和主流干涉情况。结果表明:攻角为负且数值增大时,分离区增多,分离强度增大,分离区更加靠近叶型中部,并且叶片顶部边界层很容易分离,造成的主流蒸汽能量损失更大。

Taking high-pressure reaction stage of a 300MW steam turbine as the object of study, the cascade internal flow patterns under different incidence conditions were simulated through k-to turbulence model in FLUENT and SIMPLEC algorithm, including the analysis of the emergence and development of the secondary flow and its interference with mainstream in the channel and at different AOA. The results show that while the AOA is negative and the value increases, both separation zones and the separation strength increase;and the separation zone is closer to the center of the blade profile, and the top of the wall boundary layer is vulnerable to separate which may cause greater energy loss of the mainstream steam.