Journal ArticleDOI
Postinstability Behavior of a Two-Dimensional Airfoil with a Structural Nonlinearity
TLDR
In this article, a two-dimensional airfoil with a free-play nonlinearity in pitch subject to incompressibl e flow was analyzed and the aerodynamic forces were evaluated using Wagner's function and the resulting equations integrated numerically to give time histories of the air-foil motion.Abstract:
A two-dimensiona l airfoil with a free-play nonlinearity in pitch subject to incompressibl e flow has been analyzed. The aerodynamic forces on the airfoil were evaluated using Wagner's function and the resulting equations integrated numerically to give time histories of the airfoil motion. Regions of limit cycle oscillation are detected for velocities well below the linear flutter boundary, and the existence of these regions is strongly dependent on the initial conditions and properties of the airfoil. Furthermore, for small structural preloads, narrow regions of chaotic motion are obtained, as suggested by power spectral densities, phase-plane plots, and Poincare sections of the airfoil time histories. The existence of this chaotic motion is strongly dependent on a number of airfoil parameters, including, mass, frequency ratio, structural damping, and preload.read more
Citations
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Journal ArticleDOI
Aeroelastic instability problems for wind turbines
TL;DR: In this article, the authors deal with the aeroelastic instabilities that have occurred and may still occur for modern commercial wind turbines: stall-induced vibrations for stall-turbines, and classical flutter for pitch-regulated turbines.
Journal ArticleDOI
Identification and Control of Limit Cycle Oscillations in Aeroelastic Systems
TL;DR: In this paper, the authors describe the development of control strategies appropriate for nonlinear aeroelastic systems, and the resulting closed-loop stability, based on a partial feedback linearization, is discussed.
Journal ArticleDOI
Nonlinear Aeroelasticity and Unsteady Aerodynamics
Earl H. Dowell,Deman Tang +1 more
TL;DR: The von Karman lecture as mentioned in this paper discusses the state of the art in nonlinear aeroelasticity and unsteady aerodynamics and identifies several of the most significant nonlinearities arising in a structure or in an aerodynamic flow field.
Journal ArticleDOI
Adaptive Feedback Linearization for the Control of a Typical Wing Section with Structural Nonlinearity
TL;DR: In this paper, an adaptive, nonlinear feedback control methodology for a structurally nonlinear typical wing section was derived utilizing an explicit parameterization of the structural nonlinearity and a partial feedback linearizing control that is parametrically dependent is defined via Lie algebraic methods.
Journal ArticleDOI
Renaissance of Aeroelasticity and Its Future
TL;DR: In this article, the authors demonstrate that the field of aeroelasticity continues to play a critical role in the design of modern aerospace vehicles, and several important problems are still far from being well understood.
References
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Book
Nonlinear Dynamics and Chaos
TL;DR: In this paper, the authors present a broad overview of nonlinear phenomena point attractors in autonomous systems, including limit cycles in autonomous system, and chaotic behaviour of one-and two-dimensional maps.
Book
An introduction to the theory of aeroelasticity
TL;DR: An introduction to the theory of aeroelasticity, An Introduction to the Theory of Aero-Elasticity as mentioned in this paper, An introduction to aero-elasticities,
Journal ArticleDOI
A Recurrence Matrix Solution for the Dynamic Response of Elastic Aircraft
TL;DR: A systematic procedure is developed for the calculation of the structural response of an airplane subject to dynamic loads, with particular attention given to determining the stresses developed due to flight through gusts.
Journal ArticleDOI
An Investigation of Effects of Certain Types of Structural NonHnearities on Wing and Control Surface Flutter
TL;DR: In this article, the effects of nonlinear structural terms on the flutter of a wing capable of bending and twisting and, also, of a system including a control surface are investigated, including free play, a hysteresis loop, and cubic variations.
Journal ArticleDOI
The aeroelastic response of a two-dimensional airfoil with bilinear and cubic structural nonlinearities
TL;DR: In this article, a two-dimensional airfoil with either a bilinear or cubic structural nonlinearity in pitch, and subject to incompressible flow has been analyzed using Wagner's function.