Aero-elastic stability analysis of an axial compressor with splitter rotor

The aero-elasticity of an axial compressor with splitter rotor was investigated by employing energy method and time-domain method. The aerodynamic modal damping ratio of blade and unsteady aerodynamic work distribution on the blade surface were obtained while the frequency domain analysis of blade vibration displacement were made; the conventionally designed rotors and the splitter rotor were also compared. The results show that the structural mistuning and aerodynamic mistuning had significant positive effects on the aero-elastic stability of the system. Aerodynamic mistuning improved the unsteady aerodynamic work distribution on the blade surface and the structural mistuning weakened the effect of interblade phase angles. For the first vibration mode, aerodynamic modal damping ratio (AMDR) of the splitter rotor has the value of 0.000 791, and that of conventionally designed rotors have the value of 0.000 217. Therefore, the structure of the splitter rotor not only has a better aerodynamic performance, but also enhanced the aero-elastic stability.