The Effect of Angle of Attack on Limit Cycle Oscillations for High-Aspect-Ratio Wings

In this study, the effect of the angle of attack on aeroelastic characteristics of high aspect ratio wing models with structural nonlinearities in unsteady subsonic aerodynamics flows are investigated. The studied wing model is a cantilever wing with flag, lag and torsion vibrations and with large deflection capability in according to Hodges-Dowell wing model. An unsteady low speed incompressible air flow is assumed to include the flow time lags. Variation of the limit cycle amplitudes and frequency with free stream velocity in different angle of attacks are carefully studied. For considered model, angle of attack has little effect on flutter velocity but its effect on limit cycle amplitudes and frequency is considerable. This study shows that the limit cycle amplitudes are very sensitive to variations in angle of attacks.