Abstract: Based on the Reynolds-Averaged Navier-Stokes equations and the motion equations of an airfoil,the dynamic responses of the airfoil at different incidences are computed.Both laminar and turbulent flows are taken into account.The effects of elastic vibrations on the flow fields near the stall-incidence of the airfoil are investigated.It is shown that,under the elastic vibrations,the stall-incidence of the airfoil at low or middle Reynold number will appear earlier than that in the convention fully steady flow.This result may give an explanation for the fact that the differences of the stall-incidences always exist among the numerical,wind-tunnel,and flight test approaches.

Key words: aeroelastics, separated flow, stall, stall-incidence