Accession Number:

ADA053640

Title:

Effect of Chordwise Forces and Deformations and Deformations Due to Steady Lift on Wing Flutter.

Descriptive Note:

Interim rept. 1 Apr 77-31 Mar 78,

Corporate Author:

STANFORD UNIV CALIF DEPT OF AERONAUTICS AND ASTRONAUTICS

Personal Author(s):

Report Date:

1977-12-01

Pagination or Media Count:

260.0

Abstract:

This investigation explores the effects of chordwise forces and deformations and steady-state deformation due to lift on the static and dynamic aeroelastic stability of a uniform cantilever wing. Results of this analysis are believed to have practical applications for high-performance sailplanes and certain RPVs. The airfoil cross section is assumed to be symmetric and camber bending is neglected. Motions in vertical bending, fore-and-aft bending, and torsion are considered. A differential equation model is developed, which included the nonlinear elastic bending-torsion coupling that accompanies even moderate deflections. A linearized expansion in small time-dependent deflections is made about a steady flight condition. The stability determinant of the linearized system then contains coefficients that depend on steady displacements. Loads derived from two-dimensional incompressible aerodynamic theory are used to obtain the majority of the results, but cases using three-dimensional subsonic compressible theory are also studied. The stability analysis is carried out in terms of the dynamically uncoupled natural modes of vibration of the uniform cantilever.

Subject Categories:

  • Gliders and Parachutes

Distribution Statement:

APPROVED FOR PUBLIC RELEASE