Flutter of Mistuned Bladed Disks and Blisks With Aerodynamic and FMM Structural Coupling

This paper presents the initial results from a research effort on blisk and bladed disk mistuning including both structural and aerodynamic coupling. The structural coupling model is based on the Fundamental Mistuning Model (FMM, developed by Feiner & Griffin). This effort extends the FMM technique to accept the aerodynamic coupling coefficients from computational fluid dynamic (CFD) codes. The extended model is applied to a representative engine case. The model and initial studies to identify flutter sensitivities to random and near alternate mistuning are presented. Comparisons are given of tuned and mistuned flutter for only aerodynamic coupling, and with both aerodynamic and structural coupling. For the case studied herein the beneficial effect of mistuning on flutter predicted by aerodynamic coupling models is shown to be greatly inhibited by the inclusion of the structural coupling effects.