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A Generic Nonlinear Aerodynamic Model for AircraftA generic model of the aerodynamic coefficients was developed using wind tunnel databases for eight different aircraft and multivariate orthogonal functions. For each database and each coefficient, models were determined using polynomials expanded about the state and control variables, and an othgonalization procedure. A predicted squared-error criterion was used to automatically select the model terms. Modeling terms picked in at least half of the analyses, which totalled 45 terms, were retained to form the generic nonlinear aerodynamic (GNA) model. Least squares was then used to estimate the model parameters and associated uncertainty that best fit the GNA model to each database. Nonlinear flight simulations were used to demonstrate that the GNA model produces accurate trim solutions, local behavior (modal frequencies and damping ratios), and global dynamic behavior (91% accurate state histories and 80% accurate aerodynamic coefficient histories) under large-amplitude excitation. This compact aerodynamics model can be used to decrease on-board memory storage requirements, quickly change conceptual aircraft models, provide smooth analytical functions for control and optimization applications, and facilitate real-time parametric system identification.
Document ID
20140011902
Acquisition Source
Langley Research Center
Document Type
Conference Paper
Authors
Grauer, Jared A. (NASA Langley Research Center Hampton, VA, United States)
Morelli, Eugene A. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
September 18, 2014
Publication Date
January 13, 2014
Subject Category
Aircraft Stability And Control
Report/Patent Number
AIAA Paper 2014-0542
NF1676L-16662
Meeting Information
Meeting: AIAA Atmospheric Flight Mechanics Conference
Location: National Harbor, MD
Country: United States
Start Date: January 13, 2014
End Date: January 17, 2014
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 284848.02.05.07.02
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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