Numerical investigation of blade vibration response induced by inlet distortion in axial compressor

The methodology of a fluid-solid coupled approach for the forced response of compressor blades induced by the inlet distortion is presented. The unsteady response of rotor flow field to an inlet total pressure distortion is studied by a CFD model of the entire compressor flowpath, coupled with a finite element model for the blades to identify modal shapes, natural frequencies and the structural deformation. Interaction between fluid and structure is dealt with in a coupled manner, based on the information of exchange between the aerodynamic and structural models. Results show that circumferential total-pressure distortion leads to nonuniformity of aerodynamic force of blades at different circumferential positions, causing blade vibration and stress fluctuation, producing important influence on the blade structural stability.