Aeroelastic Behaviour of a 3.5-Stage Aircraft Compressor Rotor Blades Following a Bird Strike

Abstract

This paper analyses unsteady forces acting on rotor blades in a 3.5 stage compressor following a bird strike. The strike was modelled by partially blocking the engine inlet. An in-house code was used to calculate 3D unsteady non-viscous flow of ideal gas through a 3.5 stage compressor. The numerical analysis included blade vibrations. This paper has shown that partial admission causes low-frequency harmonics to affect not only the 1st and 2nd rotor blade stages, but also the 3rd stage, with only slightly smaller amplitude values. Partial admission at the inlet strongly influenced unsteady forces in all three stages, with the dominance of low frequency unsteady force components. In the case of full admission, only high frequency components appeared, due to the number of stator blades.