Effect of fore/aft-loaded rotor on compressor stability under inlet circumferential distortion

A modified small perturbation stability prediction model for axial compressors with circumferential inlet distortions is established and applied to investigate the effect of fore/aft-loaded rotor on compressor stability under circumferentially distorted inlet conditions. The inlet total pressure distribution downstream of the distortion screen is measured in experiments and employed for simulations which are implemented via time–space spectral method. The stall inception prediction results via the stability model indicate that the compressor with aft-loaded rotor not only performs better in terms of stability under uniform inlet, but also maintains a larger stability margin under circumferentially distorted inlet. The experiments for compressors with fore-loaded and aft-loaded rotor are respectively carried out. The results validate the reliability of numerical simulations and the predicted conclusion that the aft-loaded rotor is beneficial for compressor stability. Besides, the ability of the developed theoretical model for compressor stability prediction under circumferential distortions is confirmed. In addition, dynamic pressure signals at rotor tip measured in experiments illustrate that the circumferential distortion has little effect on the compressor stall pattern.