Flutter Taming - A New Tool for the Aeroelastic Designer.

Abstract

A new concept for the design of aeroservoelastic systems is introduced: flutter taming by nonlinear control, i.e., use of nonlinear terms in the equation to ensure that the behavior of the system beyond the flutter speed is of benign rather than destructive nature. This is accomplished by using a very simple nonlinear control law. It is shown (using a singular perturbation analysis about the stability boundary) that flutter taming is always possible for an aeroservoelastic system that can be represented by a system of nonlinear differential equations with analytical nonlinearities. It is important to emphasize that the control system for flutter taming is fully nonlinear, and therefore it does not affect the linear behavior (in particular the stability characteristics) of the system. Hence, flutter taming can be used in conjunction with flutter supression by active control to increase the flutter speed). Applications of the theory to the case of an airfoil in supersonic flow are presented. In addition to an active control modification (use of control surface with nonlinear feedback), passive modifications (e.g. a nonlinear damper) are also investigated. Originator-supplied key words include: Nonlinear analysis, and Limit cycle.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1984
Accession Number
ADA150834

Entities

People

  • L. Morino

Organizations

  • Boston University

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Space

DTIC Thesaurus Topics

  • Aircrafts
  • Analytic Functions
  • Boundaries
  • Closed Loop Systems
  • Computational Fluid Dynamics
  • Computational Science
  • Control Surfaces
  • Control Systems
  • Differential Equations
  • Eigenvalues
  • Equations
  • Feedback
  • Flow
  • Fluid Dynamics
  • Nonlinear Differential Equations
  • Pressure Distribution
  • Supersonic Flow

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Calculus or Mathematical Analysis
  • Distributed Systems and Data Platform Development

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Boundary Layers