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Transonic adaptive flutter suppression using approximate unsteady time domain aerodynamicsA digital adaptive controller is applied to the active flutter suppression problem of a wing under time varying flight conditions in subsonic and transonic flow. Linear quadratic controller gain at each time step is obtained using an iterative Riccati solver. The digital adaptive optimal controller is robust with respect to the unknown external loads. Flutter and divergence instabilities are simultaneously suppressed using a trailing-edge control surface and displacement sensing. A new transonic unsteady aerodynamic approximation methodology is developed which enables one to carry out the rapid calculation required for transonic aeroservoelastic applications. This approximation is based on a combination of unsteady subsonic aerodynamics combined with a transonic correction procedure. Aeroservoelastic transient time response is obtained using Roger's approximation, state transition matrices and an iterative time marching algorithm. The aeroservoelastic system in the time domain is modeled using a deterministic ARMA model together with a parameter estimator. Transonic flutter boundaries of a wing structure are computed, in the time domain, using an estimated aeroelastic system matrix and are in good agreement with experimental data for the low transonic Mach number range.
Document ID
19910047394
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Pak, Chan-Gi
(California Univ. Los Angeles, CA, United States)
Friedmann, Peretz P.
(California, University Los Angeles, United States)
Livne, Eli
(Washington, University Seattle, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1991
Subject Category
Aircraft Stability And Control
Report/Patent Number
AIAA PAPER 91-0986
Meeting Information
Meeting: AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference
Location: Baltimore, MD
Country: United States
Start Date: April 8, 1991
End Date: April 10, 1991
Accession Number
91A32017
Funding Number(s)
CONTRACT_GRANT: F49620-87-K-0003
CONTRACT_GRANT: NCC2-374
Distribution Limits
Public
Copyright
Other

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