压气机喘振模式识别与在线检测

Pattern recognition and on-line detection for compressor surge

关键词:  压气机  喘振  模式识别  在线检测

Key words:  Compressor  Surge  Pattern recognition  On-line detection

摘要:

为发展一种运算简单、性能可靠的喘振在线检测系统,分析了压气机出口总压信号的时域和频域特性。当压气机逐渐进入喘振时,时域内表现为压力脉动强度的增大,频域内表现为信号能量在低频成分集中。选用标准差σ_p表征压力脉动强度；平均频率f表征信号频域特性。考察了由σp和f构成的模式平面,提出了一种综合时域和频域特性的喘振检测判据,检测门限可根据置信度要求进行设置,给出了在线检测系统的流程图。采用压气机试验台实测数据验证,该方法可有效地进行喘振在线检测。

Abstract:

The compressor surge greatly threatens the safe operation of an aircraft engine. To develop a simple and reliable surge on-line detection system, the characteristics of time and frequency-domain of compressor outlet total pressure signals are analyzed. When entering into surge, the pressure pulsation intensity increases in time-domain and the signal energy concentrates in low frequency components in frequency-domain. The standard deviation σp was adopted to describe the pulsation intensity of pressure and the average frequency f for frequency-domain characteristics. A new criterion of surge detection, which integrated time and frequency-domain characteristics, was developed based on the research of the pattern plane of σp and f. The threshold can be set up on the demand of confidence levels. The flow chart of on-line detection system was provided. With compressor test rig measured data, it demonstrates that this method is effective for surge on-line detection.