AERODYNAMIC AND AEROELASTIC EFFECTS OF INLET GUIDE VANE MISTUNING IN A TRANSONIC COMPRESSOR

This study applies aerodynamic mistuning using different pattern with circumferentially varying stagger angles of the inlet guide vanes. The experimental investigation is carried out at the Transonic Compressor Darmstadt, using a 1.5-stage modern front stage compressor with a BLISK rotor and variable inlet guide vanes as well as extensive instrumentation, both for aerodynamics and aeromechanics. The investigations indicate benefits with respect to NSV and influences on performance as well as steady and unsteady aerodynamics within the compressor stage, e.g. circumferentially varying operating conditions. Thus, the rotor encounters different loading conditions during one revolution, preventing the formation of coherent aerodynamic waves, able to excite and aeroelastically lock with the rotor. The circumferential variation in aerodynamics throughout the compressor stage is determined, both at steady-state and transient operating conditions. Ultimately, the goal is to derive a comprehensive understanding of underlying phenomena and aeroelastic effects, to derive feasible countermeasures for blade vibration.