Research Overview on Spike Stall Inception and Slotted Casing Treatment in Aeroengine Compressors

Rotating stall and surge are complex, unsteady flow instability phenomena in aeroengine compressors that pose serious threats to the safety and reliability of both the compressor and the engine as a whole. As aeroengine performance continues to improve, the average stage total pressure ratio and stage loading have steadily increased, presenting significant challenges in designing compressors with sufficient stall margins. In this study, we review key advances in the understanding of axial compressor instability, organizing prior research into three representative historical periods. This chronological framework aims to clarify evolving theoretical insights into the relationship between flow instability and tip-region flow dynamics in modern axial compressors. We then summarize the development of casing treatments, including their discovery, major configurations, and applicability across different compressor types. Subsequently, we systematically examine research on slot-type casing treatments, covering early-stage performance investigations, structural optimization based on experimental and numerical methods, and the underlying mechanisms responsible for stability enhancement. Finally, we offer recommendations and outline future research directions to guide further advancements in this field.