Pre-Stall Pressure Measurements of a Low-Speed Single-Stage Axial-Flow Compressor

The flow behavior near the aerodynamic stability limit of a low-speed single-stage axial flow compressor is investigated using multiple configurations of casing mounted high frequency response pressure transducers. Time variant pressure measurements are acquired at discrete operating points up to the stall inception point and during the transition to rotating stall. Multiple data analysis techniques are used to characterize breakdown of flow periodicity and the stall inception mechanism. The University of Kentucky Low Speed Research Compressor has a two node rotating disturbance that develops at a flow coefficient of 0.4 with a propagation of approximately 23% rotor speed. During rotating stall, a single stall cell is present with a propagation velocity of 35% rotor speed. The stall inception events for the University of Kentucky Low Speed Research Compressor are generated by of a modal disturbance leading to local flow separation and stall cell development.