Investigation of fluid-induced vibration caused by low engine order total pressure distortions

The compressor blade in an aero-engine may suffer from fluid-induced vibration problems due to unsteady aerodynamic forces resulting from disturbances from multiple sources, such as inlet distortion or rotating stall. However, the mechanism for quantifying the interaction between periodic aerodynamic disturbances and blade vibrations in a complex multi-physical coupling field has not been fully clarified. This study is based on an isolated rotor of a transonic compressor test rig with total pressure distortion, and the aeroelastic stability and response at partial rotational speeds were investigated. The results show that the unsteady aerodynamic force on the blade is significantly affected by incoming flow distortion, The variation in the extension angle significantly affects the flow field but does not result in a substantial change in the vibration response. The unsteady pressure amplitude is mainly affected by the distortion intensity and radial position. Furthermore, a single degree of freedom (SDOF) model is applied in the research to evaluate the vibration responses. This study is helpful to better understand the aeroelastic behavior of compressors under inflow distortion, and accurately evaluate the harmfulness of Low Engine Order (LEO) forced response under these conditions.