An Equivalent Blisk Model Considering the Influence of the Air Flow on Blade Vibrations of a Mistuned Compressor Blisk

A discrete blisk model composed by mass-, spring- and dashpot-elements, the so called Equivalent Blisk Model (EBM) is adapted to the mechanical properties of a real high pressure compressor blisk considering measured vibration data. Aiming to integrate the aerodynamic influences in the EBM, aerodynamic influence coefficients derived from aeroelastic computations are employed. Intensive numerical analyses of the forced response behavior of the blisk are performed. In addition, probabilistic mistuning analyses are carried out to assess the influence of increasing mistuning on the response amplification in dependence on the excitation order. Since the coupling between disk and blades is one of the governing parameters affecting the forced response, the influence of the disk's stiffness is studied varying the stiffness of those springs representing the disk.