The coalescence of a helicopter rotor lagging mode and its coupled rotor/airframe modes can lead to an instability phenomenon called air resonance. This paper investigates the use of piezoactuated trailing-edge flaps to actively enhance the damping of the rotor mode involved in this aeromechanical phenomenon. Numerical simulations as well as flight-test data for the hingeless EC145 helicopter with trailing-edge flaps were used for this purpose. Initially, a numerical model was validated against flight-test data in order to match accurately the phase and gain of the dynamic behavior of the helicopter system actuated by the trailing-edge flaps. The validated model was then used to design a model-based controller for rotor blade lead-lag damping enhancement. The performances of the closed-loop concept were then assessed in simulations and flown during flight tests for the first time for rotor stability enhancement. The presented results show a significant improvement in the transfer behavior of the system at the frequency of the rotor’s first regressive lagging mode as well as a strong increase in its damping. It is shown that this is true without the necessity of gain scheduling and interaction with other dynamics.


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    Title :

    Helicopter Rotor In-Plane Stability Enhancement Using Trailing-Edge Flaps


    Contributors:

    Published in:

    Publication date :

    2013-09-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English





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