Bifurcation analysis of the vibrating airfoils with large thickness at high incidences

The unsteady flows are computed based on the Reynolds-Averaged Navier-Stokes equations with SST turbulence model. Coupled with the equations of motion for elastic supported airfoils, the aeroelastic responses of airfoils with large thickness are simulated in time domain. Especially, the bifurcation responses of thick airfoils at certain range incidences are comprehensively investigated. Results indicate that the aeroelastic response at high incidence is significantly influenced by the separation flow. For the given Reynolds numbers and structure parameters considered in paper, the bifurcation phenomena appear in the aeroelastic responses of the airfoils with thickness larger than 20%. By analyzing the unsteady flow fields, it is found that transition of the equilibrium of separation flow results in the bifurcation responses.