Oscillating Airfoil Aerodynamics of a Rotating Compressor Blade Row

Abstract

Experiments are performed in a research compressor directed at investigating the aerodynamic damping unsteady aerodynamics of a rotor blade row. Specie cally, the torsion mode unsteady aerodynamics of the e rst-stage rotor of a research compressor are investigated and quantie ed, including the effects of oscillation amplitude and steady aerodynamic loading. An experimental ine uence coefe cient technique is implemented in conjunction with a unique torsion mode drive system that provides rotor blade torsion mode oscillations without other motor drive systems.Theoscillatingairfoilsurfaceunsteady pressureine uencecoefe cientdataareacquiredwith dynamicpressure transducers embedded in the rotor blades. The resulting rotor blade aerodynamic damping oscillating airfoil data are then correlated with a linear theory prediction. In general, the unsteady pressure ine uence coefe cient data decay rapidly with increasing distance from the reference blade, with different ine uences on thepressure and suction surfaces. Oscillationmagnitudeand steadyloading havea signie canteffectonboththeine uence coefe cient data and the equivalent all-airfoils-oscillating unsteady pressure data.