Accession Number:

ADA169350

Title:

Forced Oscillation of a Two-Dimensional Airfoil with Nonlinear Aerodynamic Loads (Oscillation Forcee d'un Profil de Voilure Bidimensionnel sous des Charges Aerodynamiques Non Lineaires).

Descriptive Note:

Aeronautical rept.,

Corporate Author:

NATIONAL AERONAUTICAL ESTABLISHMENT OTTAWA (ONTARIO)

Personal Author(s):

Report Date:

1986-01-01

Pagination or Media Count:

52.0

Abstract:

Forced oscillation of a two dimensional airfoil with attached and separated flows is investigated using nonlinear unsteady aerodynamics for pitching motion derived from a time synthesization technique utilizing oscillatory loop data determined experimentally. Both one and two degree of freedom oscillations are considered. The structural dynamic equations of motion are integrated by a time marching finite difference scheme. The airfoil response is examined for different values of spring stiffness and magnitudes of externally applied moment. For two degree of freedom vibration, only small plunge amplitude is considered and the aerodynamic loads are approximated by the superposition of nonlinear terms due to pitch and linear terms due to plunge. The presence of a small amplitude plunging motion increases the pitch amplitude slightly for attached flow, while a decrease in pitch amplitude is predicted for separated flow.

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE