叶尖泄漏与压气机叶栅三维角区分离相互作用实验研究

Experimental Investigation on Interaction Between Tip Clearance Flow and Three-Dimensional Separation in Compressor Cascade

关键词:  压气机叶栅  间隙流动  三维分离  来流角度

Key words:  Compressor cascade  Tip clearance flow  Three-dimensional separation  Inlet flow angle

摘要:

为了进一步揭示叶顶泄漏与压气机叶栅三维角区分离流动的相互作用机制,采用五孔气动探针测量了叶栅出口截面气动参数,并对机匣端壁静压进行了测量,详细分析了不同间隙尺寸及来流角度时压气机叶栅间隙流对角区三维分离流动的影响机理。研究结果表明,适当大小叶顶间隙引入的泄漏流阻止了端壁二次流动与叶片吸力面附面层之间的相互作用,移除了三维角区分离,改善了叶栅性能。随着叶顶间隙尺寸及叶栅内气流折转程度的增加,叶顶泄漏涡与上通道涡间的相互作用程度逐渐增强。

Abstract:

In order to further uncover the interaction of tip clearance flow with three-dimensional separation in the corner region of a compressor cascade, detailed experimental investigations were carried out. The outlet aerodynamic parameters were measured by five hole pneumatic probe, and the distribution of the static pressure on the endwall was obtained. The effects of tip clearance size and inlet flow angle on the interaction of tip clearance flow with three-dimensional separation in a compressor cascade were analyzed in detail. The results show that the three-dimensional separation on the blade suction surface is largely removed by the clearance flow for a proper tip clearance size and the aerodynamic performance of the cascade is improved. The removal mechanism is associated with preventing the endwall fluid from interacting with the suction surface boundary layer by the clearance flow. The interaction between the leakage vortex and the tip side passage vortex turns stronger with increasing the clearance size and the flow turning. 