Simultaneous Vibration and Noise Reduction in Rotorcraft Using Aeroelastic Simulation

A study of the combined helicopter noise and vibration reduction problem was conducted. A fully coupled aeroelastic and aeroacoustic simulation tool is developed, with special attention placed on enhancing the resolution of the free wake model used. Subsequently, this tool is validated with experimental aerodynamic and acoustic data. Control algorithms for noise and vibration problems are studied. The simulation is used to conduct a detailed study of noise and vibration reduction problems in heavy blade-vortex interaction descent flight. Actively-controlled flaps are used to reduce noise and vibrations, and changes to the aerodynamic environment around the rotor is monitored. Simultaneous reduction of noise and vibration is successfully implemented with a dual active flap configuration. Physical sources of increased vibration during noise reduction, and increased vibration during noise reduction are examined, and the power required to reduce noise and vibration is compared to baseline rotor power.