Unsteady Leading Edge Suction Effects on Rotor-Stator Interaction Noise

摘要

A strictly linear analysis of the sound generated by an unleaned stator yields a211u001evanishing amplitude for models with zero circumferential periodicity. In such a 211u001ecase higher order effect of stator leading edge suction on radiated sound is 211u001eaddressed. By a local analysis in the vicinity of the leading edge a suction 211u001eforce can be restored from the first order theory. This suction force oscillates 211u001eat twice the frequency of the associated blade loading. Numerical examples show 211u001ethat the effect provides a realistic floor level for the sound that otherwise 211u001ewould seem to vanish. For non-zero circumferential modal wave numbers the effect 211u001ecan increase the acoustic intensity by as much as 10dB.