基于声压信号的某型涡轴发动机喘振识别

Surge identification of a turboshaft engine based on sound pressure signal

为了识别某型涡轴发动机喘振时的特征,通过进气畸变方式开展了某型发动机台架试车逼喘试验,利用声压传感器测量采集了轴流压气机和离心压气机两侧的声压信号。对声压信号进行测试环境与背景噪声修正,再采用时频分析方法实现了对由于进气减少引起的压气机叶片失速团特征和低频喘振特征的检测,并采用小波低频重构声压信号方法实现了某型涡轴发动机喘振信号的提取与识别。结果表明:随着进气的增加,轴流压气机和离心压气机转子频率处声压信号幅值会降低,同时会产生失速团,轴流压气机右侧能最先监测到喘振,喘振频率约为60 Hz。

In order to identify the characteristics of a turboshaft engine during surge,the bench test of a turboshaft engine was carried out by inlet distortion method,and the sound pressure signals on both sides of axial compressor and centrifugal compressor were measured and collected by sound pressure sensor.The test environment and background noise of sound pressure signal were corrected,the characteristics of compressor blade stall mass and low-frequency surge caused by intake reduction were detected by time-frequency analysis method,and the surge signal of a turboshaft engine was extracted and identified by wavelet low-frequency reconstruction of sound pressure signal.The results showed that with the increase of intake air,the amplitude of sound pressure signal at the rotor frequency of axial flow compressor and centrifugal compressor decreased,and stall mass was generated.Surge can be first detected on the right side of axial flow compressor,with the surge frequency about 60 Hz.