Test Investigation Of Unsteady Flow Frequency Domain Performance In A Low Speed Axial Compressor

In order to investigate the unsteady flow frequency domain performances of an axial flow compressor at different mass flow, rotating speed and blade row spacing, plus inlet flow distortion, and considering aerodynamic characteristics and stability of the compressor, the low speed research compressor(LSC) at College of Energy and Power in NUAA is used to carry out the experiment studies. A large amount of test data has been gained through dynamic pressure transducers embedded in the stator blades at the tip, middle and hub section, then Fast Fourier Transform Algorithm(FFT) is applied to calculate the frequency data.The experimental results show that the unsteady flow frequency domain performances of the axial flow compressor will be varied with mass flow, rotating speed , blade row spacing and inlet distortion. The compressor exists about 0.265 rotor blade converted frequency near stall point, its intensity increases with rising of rotating speed and reducing blade row spacing. The blade row spacing would exert influences on rotor-stator interaction, stability and stall mode. The stability will fall when inlet flow is distorted. A circumferential critical distorted angle exists in the compressor, the stability of the compressor will change little when circumferential distorted angle is greater than critical distorted angle.