Aeroelastic behavior of offshore wind turbine airfoil during typhoon

In this paper, the aeroelastic behavior of the wind turbine FFA-W3-211 two-dimensional airfoil in the dynamic stall regime has been investigated during the natural typhoon real time history. What's more, the interaction between the airfoil stall-induced vibration and the unsteady flow has been effectively taken into consideration. Based on Navier-Stokes equation and k-ω SST turbulence model, the aerodynamic loads acting on the airfoil have been obtained by numerical simulation of the unsteady flow field near the airfoil under large angle of attack. Subsequently, the aerodynamic response of the airfoil can be calculated by embedding structural dynamics Newmark-β codes into the flow solver. Finally, the nonlinear interaction between the airfoil vibration and the unsteady flow can be successfully studied by taking advantage of the moving mesh technique for the simulation of the airfoil dynamic responses. Three kinds of stall-induced vibration have been considered: pitching oscillation, flap-wise oscillation and flap-pitching two degree-of-freedom coupled oscillation. Consequently, the key factors for the wind turbine two-dimensional airfoil aeroelastic performance during natural typhoon have been pointed out. Furthermore, the main reasons have been clarified in views of physical mechanism for fluid-structure interaction.