Third M.I.T. Conference on Computational Fluid and Solid Mechanics June 14–17, 2005  

Effects of unsteady aerodynamics on the dynamic response of mistuned bladed disks

Zhijiang He, Bogdan I. Epureanu*, Christophe Pierre
University of Michigan, Department of Mechanical Engineering, Ann Arbor, MI 48109, USA

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This paper presents the preliminary results of studies on the dynamics of mistuned bladed disks including both structural and aerodynamic coupling. Aerodynamic coefficients calculated from a quasi-3D unsteady aerodynamic code are incorporated into a high-fidelity structural model employing the component mode mistuning (CMM) method. The extended CMM model is applied to the analysis of the dynamics of an industrial compressor stage. The eigenvalue structures of the tuned and mistuned systems including aerodynamic coupling are compared for the cases without structural damping, with small structural damping and with large structural damping. Also, the effect of aerodynamic coupling on the forced response of the system is investigated. For the cases studied, the large structural damping can change the eigenvalue structure of the mistuned system. Under certain conditions, the aerodynamic coupling is shown to decrease the mistuned forced response amplification factor compared to the tuned forced response.

Keywords:  Mistuning; Structural coupling; Aerodynamic coupling; CMM model; Eigenvalue structure; Forced response

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