Abstract: Based on the Reynolds-Averaged Navier-Stokes equationsand k-\omega SST turbulent models, the steady and unsteady flows arecomputed. Coupled with the motion equations for an elastic supportedairfoil, the aeroelastic dynamic responses of the symmetric airfoil withdifferent thicknesses at different incidences are simulated in the timedomain. The flow-field characteristics and the aeroelastic characteristicsof airfoil with different thicknesses at high-incidence are investigated. Itis shown that, the critical flutter speed does not vary monotonously withthe incidence increasing from zero to high levels for various Reynolds numbersand structure parameters considered in this paper. The incidence at whichthe critical flutter speed begins to drop rapidly is much smaller than theincidence corresponding to the maximum lift coefficient.