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Method and System for Active Noise Control of Tiltrotor AircraftMethods and systems for reducing noise generated by rotating blades of a tiltrotor aircraft. A rotor-blade pitch angle associated with the tiltrotor aircraft can be controlled utilizing a swashplate connected to rotating blades of the tiltrotor aircraft. One or more Higher Harmonic Control (HHC) signals can be transmitted and input to a swashplate control actuator associated with the swashplate. A particular blade pitch oscillation (e.g., four cycles per revolution) is there-after produced in a rotating frame of reference associated with the rotating blades in response to input of an HHC signal to the swashplate control actuator associated with the swashplate to thereby reduce noise associated with the rotating blades of the tiltrotor aircraft. The HHC signal can be transmitted and input to the swashplate control actuator to reduce noise of the tiltrotor aircraft in response to a user input utilizing an open-loop configuration.
Document ID
20040013330
Acquisition Source
Ames Research Center
Document Type
Other - Patent
Authors
Mark D Betzina
Khanh Q Nguyen
Date Acquired
August 21, 2013
Publication Date
December 30, 2003
Subject Category
Aircraft Design, Testing And Performance
Report/Patent Number
NASA-Case-ARC-14606-1
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
Patent
US-Patent-6,671,590
Patent Application
US-Patent-Appl-SN-139256
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