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Active Flap Control of the SMART Rotor for Vibration ReductionActive control methodologies were applied to a full-scale active flap rotor obtained during a joint Boeing/ DARPA/NASA/Army test in the Air Force National Full-Scale Aerodynamic Complex 40- by 80-foot anechoic wind tunnel. The active flap rotor is a full-scale MD 900 helicopter main rotor with each of its five blades modified to include an on-blade piezoelectric actuator-driven flap with a span of 18% of radius, 25% of chord, and located at 83% radius. Vibration control demonstrated the potential of active flaps for effective control of vibratory loads, especially normal force loads. Active control of normal force vibratory loads using active flaps and a continuous-time higher harmonic control algorithm was very effective, reducing harmonic (1-5P) normal force vibratory loads by 95% in both cruise and approach conditions. Control of vibratory roll and pitch moments was also demonstrated, although moment control was less effective than normal force control. Finally, active control was used to precisely control blade flap position for correlation with pretest predictions of rotor aeroacoustics. Flap displacements were commanded to follow specific harmonic profiles of 2 deg or more in amplitude, and the flap deflection errors obtained were less than 0.2 deg r.m.s.
Document ID
20090036805
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Hall, Steven R.
(Massachusetts Inst. of Tech. Cambridge, MA, United States)
Anand, R. Vaidyanathan
(Boeing Co. Mesa, AZ, United States)
Straub, Friedrich K.
(Boeing Co. Mesa, AZ, United States)
Lau, Benton H.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 24, 2013
Publication Date
May 27, 2009
Subject Category
Aircraft Stability And Control
Report/Patent Number
ARC-E-DAA-TN590
Meeting Information
Meeting: American Helicopter Society 65th Annual Forum and Technology Display
Location: Grapevine, TX
Country: United States
Start Date: May 27, 2009
End Date: May 29, 2009
Sponsors: American Helicopter Society, Inc.
Distribution Limits
Public
Copyright
Other

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