轴流涡轮叶尖泄漏流动实验测量技术研究进展

基于公开文献与课题组现有实验研究成果，总结轴流涡轮叶尖泄漏流动实验测量的研究现状，并对未来发展方向进行展望。实验装置方面，现有大多数实验研究基于涡轮平面叶栅，针对旋转状态下间隙泄漏流动的测量较少；测量工况方面，低速条件下的实验研究较多，针对跨声速、超声速叶尖泄漏流动的研究较少；测量方法方面，多数实验为稳态定量和定性测量，且着眼于出口流场，针对涡轮转子叶尖间隙内部流动结构的非接触、瞬态测量研究较少；结果分析方面，多数实验着眼于分析泄漏流动对涡轮性能的影响，对泄漏涡非定常流动机理、泄漏涡与二次涡系的相互作用以及涡破碎的揭示尚不完全。基于涡轮转子实验台，结合端壁动态压力测量阵列，采用内窥式PIV、LDV技术对涡轮转子叶尖间隙内部及附近非定常泄漏流动的测量是一个亟待深入研究的重要方向。

Progress of experimental research on axial turbine tip leakage flow

Based on the public literature and experimental results obtained by our group, the experimental research for the axial turbine tip leakage flow is summarized, and the future development is also prospected. The analysis shows that most researches are still based on the linear turbine cascade, and there are few measurements on the tip leakage flow under rotating conditions. As for the measurement methods, steady-state, quantitative and qualitative measurements which focus on the outlet flow field are still dominant, while non-intrusive and transient measurements inside the tip gap are relatively deficient. As for the measurement conditions, many studies are conducted at low speed condition, but only few studies are conducted under transonic and supersonic condition. Meanwhile, most analyses focus on the effect of the leakage flow on the turbine performance, but the unsteady flow mechanism of the tip leakage vortex and its breakdown is not fully revealed. In the future, based on the turbine rotor test rig, using the end-wall dynamic pressure measurement array, endoscopic PIV, and LDV to measure the unsteady leakage flow inside and near the tip clearance is an important direction that needs to be studied urgently.