论文部分内容阅读
为了研究高负荷低压涡轮边界层的非定常转捩过程及雷诺数对尾迹边界层相互作用机制的影响,采用热线和表面热膜测试技术在高负荷叶栅实验台上对吸力面边界层的非定常时空演化进行了实验测试。结果表明:高负荷叶型的吸力面边界层在没有来流尾迹作用的情况下会不可避免地发生分离。分离剪切层中的K-H无粘不稳定机制主导了失稳转捩过程;来流尾迹的逆射流会与边界层相互作用,产生卷起涡结构,从而促进分离剪切层的转捩过程。边界层的分离被转捩产生的湍流条带及其后的寂静区抑制;随着雷诺数降低,分离点向上游移动11.4%吸力面弧长,分离泡的流向和法向范围扩大,尾迹引起的卷起涡结构尺度也随之变大。雷诺数通过改变分离剪切层的状态对转捩机制产生影响。
In order to study the influence of unsteady rotation process of high-pressure and low-pressure turbine boundary layer and the Reynolds number on the interaction mechanism of wake boundary layer, hot wire and surface hot film test technique were used to simulate the non- The experiment of constant space-time evolution was tested. The results show that the boundary layer of the suction side of the high-load leaf type will inevitably segregate without wake flow. The mechanism of K-H non-viscous instability in the separation-shear layer dominates the instability transition process; the back-jet flow of the wake of the flow will interact with the boundary layer to produce a rolled-up vortex structure, thereby facilitating the transition of the shear layer. As the Reynolds number decreases, the separation point moves upstream by 11.4% of the arc length of the suction surface, the flow direction and the normal range of the separation bubble expand, and the wake causes The volume of the rolled-up vortex also increases. The Reynolds number affects the mechanism of transition by changing the state of the separation shear layer.