The dynamic pressure signals were measured and analyzed by the Kulite transducers and the fast response pressure probes to investigate the rotor-stator interaction phenomenon in small multistage axial compressor. Results indicated that

at higher rotor speed

the 1st rotor tip flow-field agreed well with the typical supersonic-cascade flow features

and only the flow-field at the 1st rotor trailing-edge was disturbed by the rotor-stator interactions. However

at lower rotor speed

the rotor-stator interaction obviously increased in intensity and appeared at the 1st rotor leading-edge with the compressor throttling. Modal analysis was carried out for these frequency components of rotor-stator interactions

and then the propagation speed and modal number were obtained finally.