Dynamic Blade Shapes for Improved Helicopter Rotor Aeromechanics

HyPerComp Inc. is teaming with NextGen Aeronautics and the Rotorcraft Center at the University of Maryland (UMCP) to explore the use of dynamic blade shapes (morphing) for improved rotor performance. In the ongoing Phase-I of this project we are investigating open-loop morphing of leading-edge, trailing-edge, and twist of the UH60A rotor using a comprehensive, coupled CFD-CSD software suite. For high-speed forward flight, about 3% power-saving using trailing-edge deflection and about 3% improvement in the rotor lift-to-drag ratio using active twist was demonstrated. For the high-thrust case, about 7% power-saving was obtained using leading-edge nose droop on the retreating side. A novel, comprehensive analysis approach using full CFD has been developed and shown to work efficiently in modeling morphing rotor dynamics. In the proposed Phase-II study we seek to complete this investigation, leading to a full rounded understanding of morphing rotorcraft design. We will address a broader set of flight conditions and morphing concepts. Full CFD-CSD analyses will be supplemented with industry standard comprehensive analyses coupled with acoustics, vibrations and aero-elastic effects thus accentuating the impact of this work. A paper study of actuator design and requirements will be made, and an existing morphing rotor prototype will be adapted to create a bench test model to demonstrate practical considerations.