Influence of Dynamic Inflow States on Coupled Rotor Fuselage Modes

Dynamic inflow effects on stability and modes of a coupled rotor-fuselage system are investigated. Dynamic inflow effects are incorporated using Peters-He model. Characteristics of different modes associated with a coupled rotor-fuselage system are investigated. In addition to the magnitude of the states in the eigenvector (periodic eigenvector in general), phases of the states are also used to characterize the modes. From this approach, the effect of wake on different modes is demonstrated for two earlier tested configurations under ground-contact conditions. The ambiguity in naming a mode (due to participation of different states) is resolved from the relative phases of the relevant states.