Aerodynamic Mistuning of Structurally Coupled Blades

Abstract

This paper discusses the impact of aerodynamic mistuning in the context of a structurally coupled blade system. The aerodynamic mistuning assumes a difference in blade loading (between adjacent blades) but no change in eigenfrequency or modeshape. Thus, emphasis is placed on the profile shape impact of transonic rotor blades on aeroelasic damping. An example aeroelasic calculation of the proposed mistuning strategy is present for a coupled blade arrangement. The impact of mistuning compared to the tuned datum profile is discussed. It is shown that there exist significant differences for the two configurations but that the net impact of mistuning is small for the coupled system investigated compared to a freestanding blade design.