Influence of Blade Vibration on Part-Span Rotating Stall

This paper presents the interaction between blade vibration and part-span rotating stall in a multi-stage high speed compressor. Unsteady aerodynamic aeroelastic simulations were conducted using URANS CFD. Steady state computations showed short length scale disturbances formed local to tip of front stage rotor. Using full annulus model, these shown coalesce into flow structures around at approximately 76% shaft rotational speed. Natural evolution did not result coherent spatial pattern. Subsequent analyses carried out with prescribed rotor ‘lock-in’ event where circumferential order shifted match that induced by mode. Moreover, contrast its natural form absence vibration, fully developed signal.