Time-frequency characteristics of stator passage pressure signal of aeroengine compressor

Tests on aeroengine were conducted to obtain stator passage pressure signal of the first compressor stage of a test aeroengine.By means of time-frequency analysis,the time-frequency structures centered on550 Hz and 2200 Hz were identified;the blade passing frequency of the first 3 compressor rotors,and some of their sum-frequency and difference frequency signals,were identified too.It's also observed that for the first 3 compressor rotors,in the process of engine throttling,the blade passing frequencies,their sum-frequency and difference frequency signals would gradually increase their magnitudes before the opening of discharge valve,which indicated that the first compressor tip region flow separation became server following the decrease of engine speed.Thus compressor rotor flow field information might be obtained through monitoring the time-frequency characteristics of pressure signal of specific compressor stator passage,which was helpful for the control of compressor stability.