Resonant Response of Mistuned Bladed Disks Including Aerodynamic Damping Effects

A mathematical model is developed to investigate the effects of aerodynamic damping on the maximum-amplification factor of mistuned bladed disks. LINSUB, an inviscid linearized unsteady aerodynamic damping code, provides aerodynamic damping influence coefficients that are incorporated into a partial mistuning model that takes advantage of mode localization. This mistuning analysis is then used to demonstrate the effects of aerodynamic damping on the maximum-amplification factor of mistuned bladed disks. The relative importance of aerodynamic effects is determined by a comparison of aerodynamic and structural damping factors. It is shown that neglecting unsteady aerodynamics may result in the predicted optimal mistuning pattern not being optimum in the actual operating environment wherein unsteady aerodynamic effects are present. [PUBLISHER ABSTRACT]