Investigation on Aeroacoustics and Aerodynamics of the Stator Lean Effect for Rotor-Stator Interaction

The rotor-stator interaction in a 1.5 stage compressor with different lean angle of downstream stator blades was investigated by aeroacoustic and numerical study. The aeroacoustic performance with narrow spectra, the sound pressure level distribution and the unsteady loading of the compressor were tested and analyzed. The RMS pressure, the axial thrust and torque of the downstream stator blade distribution revealed the unsteady characteristic of rotor-stator interaction at different downstream stator blade lean angle. The positive lean stator had better noise constraint than the negative lean stator. However, the RMS pressure and the unsteady force increased with the increase of the lean angle when the stator had positive lean angle. The time-spatial contours of the axial velocity demonstrated the effect of time delay for the rotor wake intersection with the leading edge of the stator blade. And the phase lag distribution of the wake presented the detail distribution of the wake phase along the span. The downstream stator blade lean was effective to obtain a significant reduction for the unsteady force and get large phase lag for the rotor’s wake of rotor-stator interaction. Leaned positive blade had better benefits than negative for the noise reduction and the phase lag of the wake.