关键词: 轴流式压气机;失速;静压;时频分析;气动稳定性

Abstract: To investigate the internal relationship between blade passing frequency (BPF) characteristics of compressor rotors and aerodynamic stability of corresponding compressor, time-frequency analysis was performed to analyze stator casing wall static pressure of axial flow compressor of a certain single-spool turbojet engine. Data processing results show that the variation of compressor rotor BPF characteristics during engine operation can reflect flow regime transients of a specific compressor stage. As engine operating point gradually approaches the surge line at part-speed operation, compressor rotor BPF magnitudes of casing wall static pressure of the first three compressor stages gradually increase. As compared with design point, the BPF magnitude of the first compressor rotor gets an augmentation of more than 10 dB at near stall conditions. Moreover, the BPF magnitudes of the front compressor stages decrease notably as the bleed valve is opened at part-speed, which is consistent with the improvement of flow field induced by the bleeding. Thus, BPF characteristics of axial flow compressor rotors are capable of providing important information about compressor aerodynamic stability.

Key words: Axial flow compressor;Stalling;Static pressure;Time-frequency analysis;Aerodynamic stability