跨音压气机近失速状态的非定常特征

本文采用动态测量技术和非定常流动的分析方法，对高速跨音压气机近失速状态时，动叶顶部非定常流动的演变特征进行了实验研究。从时域、频域和流场特征的角度出发，探讨了旋转失速发生和发展过程中，流动失稳的物理机制．结果表明：远离设计工况时的失速先兆特征与临近设计工况时的先兆特征有着本质的区别。展示了非稳定分离流动与后续旋转失速成因的内在联系．

UNSTEADY FLOW BEHMIOR OF NEAR--STALL STATES IN A TRANSONIC AXIAL COMPRESSOR

The current paper reports the results of a detailed experimental investigation on theunsteady flow behavior of near--stall in a single--stage transonic axial compressor. Usingboth the technique of dynamic measurement and analyzing methods of unsteady flow, theauthors study the developmental processes of the unsteady flow around the tip clearanceranges of rotor, from pre-stall to post--stall states. From the view points of the time-varyingdomain, the distribution of frequency spectrum, and the spatial structure of internal flowfield, The flow mechanism on the occurrence of stall inception and the development of stallcells are analyzed in detail. Therefore, it is observed that there edests a significant differenceon the characteristic of stall inception between at the off-designed and at the near--designedoperating state. At the same time, the connection between the separated flow of instabilityand full-developed rotating stall cells is explained.