轴流式压气机近失速状态端壁流动时频分析

为准确辨识某型单轴涡喷发动机压气机近失速点的流动特征,对其端壁静压信号进行了时频分析。时频分析结果表明,近失速点的工况下,与其它各级相比,压气机第一级静子机匣壁面流动变化最为显著;随着发动机工作点沿共同工作线趋近喘振边界,压气机第一级静子机匣壁面静压信号中以550Hz为中心的宽带信号开始出现并逐步增强。所发现的压气机端壁流态特征可用于发动机节流过程中工作点接近失速边界的程度的判定,具有一定的工程应用价值。

Time-Frequency Analysis of the Axial Flow Compressor Endwall Flow at Near Stall Conditions

To identify the flow pattern of a single-spool turbojet axial flow compressor at near stall conditions,the compressor end wall static pressure signals were analyzed using time-frequency analysis technology.The results show that at near stall conditions,the endwall flow of the first compressor stator varies dramatically compared to other stators.As the operating point runs close to the surge line along the operating line,a broad band signal centered on 550 Hz occurs and gradually builds up.The observed end wall flow patterns can be used to assess the stall margins during engine throttling,and thus,it has certain value in engineering application.