Improved Method for Creating Time-Domain Unsteady Aerodynamic Models
Publication: Journal of Aerospace Engineering
Volume 20, Issue 3
Abstract
Multidisciplinary aeroservoelastic interactions are studied by the combination of knowledge acquired in two main disciplines: aeroelasticity and servocontrols. In aeroelasticity, the doublet lattice method is used to calculate the unsteady aerodynamic forces for a range of reduced frequencies and Mach numbers on a business aircraft in the subsonic flight regime by use of NASTRAN software. For aeroservoelasticity studies, there is the need to conceive methods for these unsteady aerodynamic forces conversions from frequency into Laplace domain. A new method different from classical methods is presented, in which Chebyshev polynomials theories and their orthogonality properties are applied. In this paper, a comparison between flutter results expressed in terms of flutter speeds and frequencies obtained with our method with flutter results obtained with classical Padé and least squares methods is presented for a business aircraft at one Mach number and a range of reduced frequencies. It has been found that results obtained with our method are better in terms of average error than results obtained with the two classical methods here presented.
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Acknowledgments
The writers would like to thank to Bombardier Aerospace for their grants and collaboration on this project. In addition, the writers thank the Natural Sciences and Engineering Research Council NSERC of Canada for their grants in the aeroservoelasticity field.
References
Biskri, D. E., Botez, R. M., Therrien, S., Rathé, A., Stathopoulos, N., and Dickinson, M. (2005). “New mixed method for unsteady aerodynamic forces approximations for aeroservoelasticity studies.” Forum on Aeroelasticity and Structural Dynamics IFASD 2005 (CD-ROM), Munich, Germany.
Cotoi, I., and Botez, R. M. (2002). “Method of unsteady aerodynamic forces approximation for aeroservoelastic interactions.” J. Guid. Control Dyn., 25(5), 985–987.
Dunn, H. J. (1980). “An analytical technique for approximating unsteady aerodynamics in the time domain.” NASA TP-1738, Washington, D.C.
Gupta, K. K. (1997). “STARS–An integrated, multidisciplinary, finite-element, structural, fluids, aeroelastic, and aeroservoelastic analysis computer program.” NASA TM-4795, Washington, D.C., 1–285.
Hiliuta, A., Botez, R. M., and Brenner, M. (2005). “Approximation of unsteady aerodynamic forces by use of fuzzy techniques.” 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference (CD-ROM), Austin, Tex.
Karpel, M. (1982). “Design for flutter suppression and gust alleviation using state space modeling.” J. Aircr., 19(3), 221–227.
Noll, T., Blair, M., and Cerra, J. (1986). “ADAM, an aeroservoelastic analysis method for analog or digital systems.” J. Aircr., 23(11).
Pitt, D. M. (1992). “FAMUSS: A new aeroservoelastic modeling tool.” AIAA-92-2395.
Poirion, F. (1996). “Multi-Mach rational approximation to generalized aerodynamic forces.” J. Aircr., 33(6), 1199–1201.
Rodden, W. P., Harder, R. L., and Bellinger, E. D. (1979). “Aeroelastic addition to NASTRAN.” NASA CR-3094, Washington, D.C.
Smith, T. A., Hakanson, J. W., Nair, S. S., and Yurkovich, R. N. (2004). “State-space model generation for flexible aircraft.” J. Aircr., 41(6), 1473–1481.
Weisstein, E. W. (2004). “Chebyshev polynomial of the first kind.” MathWorld—Wolfram web, http://mathworld.wolfram.com/ChebyshevPolynomialoftheFirstKind.html .
Information & Authors
Information
Published In
Journal of Aerospace Engineering
Volume 20 • Issue 3 • July 2007
Pages: 204 - 208
Copyright
© 2007 ASCE.
History
Received: Nov 29, 2005
Accepted: Nov 28, 2006
Published online: Jul 1, 2007
Published in print: Jul 2007
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