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.