The influence of inlet distortion on the stall route in a high load compressor

This study investigates the dynamic stall process of a high-load 1.5-stage compressor under inlet radial distortion through unsteady pressure measurements. Under uniform and hub radial distortion conditions, stall inception remains modal, and tip air injection shows limited stability enhancement. In contrast, tip radial distortion increases tip loading and triggers the spike-type stall inception. Tip air injection under this condition effectively suppresses tip leakage flow (TLF) fluctuations and improves stall margin by up to 5%. Notably, spike-type inception can transition back to modal wave as the injection mass flow increases, revealing a mechanism of stability enhancement through tip unloading. These results clarify the role of tip injection in suppressing TLF-driven instabilities and provide insights into its practical application under various distortion profiles.