Mechanisms and Key Parameters for Compressor Blade Stall Flutter

Abstract

This paper describes a fluidstructure interaction (FSI) numerical method in frequency domain to improve the overall understanding of the mechanisms of compressor blade stall flutter and to identify the key flutter parameters. The numerical method, whose accuracy is verified by comparing the numerical predicted stall flutter boundary with that measured through engine rig tests in a compressor rotor, is applied to investigate the effects of blade mode, reduced velocity, and interblade phase angle (IBPA) on flutter stability, and to reveal the flutter mechanisms directly related to shock wave properties and flow separation effects. It is found that the shock wave on the suction surface and the separation area behind it are important flutter inducements.