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Reduced order nonlinear system identification methodology

Publication ,  Journal Article
Attar, PJ; Dowell, EH; White, JR; Thomas, JP
Published in: AIAA Journal
August 1, 2006

A new method is presented which enables the identification of a reduced order nonlinear ordinary differential equation (ODE) which can be used to model the behavior of nonlinear fluid dynamics. The method uses a harmonic balance technique and proper orthogonal decomposition to compute reduced order training data which is then used to compute the unknown coefficients of the nonlinear ODE. The method is used to compute the Euler compressible flow solutions for the supercritical two-dimensional NLR-7301 airfoil undergoing both small and large pitch oscillations at three different reduced frequencies and at a Mach number of 0.764. Steady and dynamic lift coefficient data computed using a three equation reduced order system identification model compared well with data computed using the full CFD harmonic balance solution. The system identification model accurately predicted a nonlinear trend in the lift coefficient results (steady and dynamic) for pitch oscillation magnitudes greater than 1 deg. Overall the reduction in the number of nonlinear differential equations was 5 orders of magnitude which corresponded to a 3 order of magnitude reduction in the total computational time. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc.

Duke Scholars

Published In

AIAA Journal

DOI

ISSN

0001-1452

Publication Date

August 1, 2006

Volume

44

Issue

8

Start / End Page

1895 / 1904

Related Subject Headings

  • Aerospace & Aeronautics
  • 4012 Fluid mechanics and thermal engineering
  • 4001 Aerospace engineering
  • 0913 Mechanical Engineering
  • 0905 Civil Engineering
  • 0901 Aerospace Engineering
 

Citation

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ICMJE
MLA
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Attar, P. J., Dowell, E. H., White, J. R., & Thomas, J. P. (2006). Reduced order nonlinear system identification methodology. AIAA Journal, 44(8), 1895–1904. https://doi.org/10.2514/1.16221
Attar, P. J., E. H. Dowell, J. R. White, and J. P. Thomas. “Reduced order nonlinear system identification methodology.” AIAA Journal 44, no. 8 (August 1, 2006): 1895–1904. https://doi.org/10.2514/1.16221.
Attar PJ, Dowell EH, White JR, Thomas JP. Reduced order nonlinear system identification methodology. AIAA Journal. 2006 Aug 1;44(8):1895–904.
Attar, P. J., et al. “Reduced order nonlinear system identification methodology.” AIAA Journal, vol. 44, no. 8, Aug. 2006, pp. 1895–904. Scopus, doi:10.2514/1.16221.
Attar PJ, Dowell EH, White JR, Thomas JP. Reduced order nonlinear system identification methodology. AIAA Journal. 2006 Aug 1;44(8):1895–1904.
Journal cover image

Published In

AIAA Journal

DOI

ISSN

0001-1452

Publication Date

August 1, 2006

Volume

44

Issue

8

Start / End Page

1895 / 1904

Related Subject Headings

  • Aerospace & Aeronautics
  • 4012 Fluid mechanics and thermal engineering
  • 4001 Aerospace engineering
  • 0913 Mechanical Engineering
  • 0905 Civil Engineering
  • 0901 Aerospace Engineering