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Determination of rotor wake induced empennage airloadsA computer program has been developed that predicts the unsteady aerodynamic forces that impinge on the empennage surface due to its interactions with the main rotor wake. The program was utilized to determine the vibration airloads acting on the Black Hawk horizontal stabilizer and on the CH-53A stabilizer under high speed forward flight conditions. The results demonstrate that it is possible to compute the high frequency empennage vibration airloads efficiently by utilizing suitable analysis techniques; a CH-53A case required only 1.3 minutes of computer time. Numerical problems associated with the unsteady Kutta condition have been minimized. Even though the analysis is of transient nature, the results for harmonic cases show a very fast convergence to periodicity. In general, good correlation was shown between the predicted vibratory airloads and the measured stabilizer airloads for a CH-53A helicopter operating at high speed flight conditions.
Document ID
19820054261
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Gangwani, S. T.
(United Technologies Research Center East Hartford, CT, United States)
Date Acquired
August 10, 2013
Publication Date
November 1, 1981
Subject Category
Aerodynamics
Report/Patent Number
AHS PREPRINT 81-26
Meeting Information
Meeting: Northeast Region National Specialists'' Meeting on Helicopter Vibration: Technology for the Jet Smooth Ride
Location: Hartford, CT
Start Date: November 2, 1981
End Date: November 4, 1981
Sponsors: American Helicopter Society
Accession Number
82A37796
Funding Number(s)
CONTRACT_GRANT: NAS1-16058
Distribution Limits
Public
Copyright
Other

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