The wake interference of wind turbines is the main factor affecting the performance and output of wind turbines downstream of the wind farm. By adjusting the attitude of the wind turbine, the wake interference effect can be effectively improved, but it also introduces more complex unsteady aerodynamic characteristics and wake field distribution. In order to study the wake characteristics of wind turbine attitude control, based on the lifting-line and free vortex wake model, the aerodynamic wake model of the horizontal axis wind turbine is established. Taking the NREL 5MW wind turbine as the research object, under the condition of rated wind speed, the wake characteristic of the turbine under yaw and tilt conditions is studied. The wake disturbance of the wind turbine yaw and tilt condition under the influence of wind shear and tower is further analyzed. The results show that, yaw and tilt will cause the instability of the wake vortex structure in advance, the turbulence intensity in the far wake region will increase, the wake center will deflect and the wake action area will decrease. In addition, yaw and tilt will accelerate the recovery of velocity deficit and reduce the interference of wake effect on the downstream. Wind shear will exert a similar effect on the tilt of the wind turbine, which will raise the wake and reduce the area of wake. The interference of the tower to the near wake region is more significant, and the tilt control will reduce the interference of the tower to the wake.

Aiming at the problem of dynamic stall of helicopter rotors under variable free stream during forward flight, a dynamic stall control method of airfoils based on the co-flow jet (CFJ) is developed. Taking NACA0012 airfoil as the research object, the unsteady Reynolds-averaged Navier-Stokes equations are solved based on the transition SST turbulence model, and numerical simulations of the dynamic stall of airfoils controlled by CFJ under different parameters are carried out. The results show that CFJ can effectively suppress the dynamic stall of airfoils. Under the condition of variable free stream, the jet channel has a negative impact on the original aerodynamic characteristics of the airfoil, and the power coefficient increases much faster than the jet momentum coefficient. There is an optimal working condition for CFJ to achieve the best control effect. CFJ accelerates the evolution of multi-vortex by mixing with the mainstream to suppress the dynamic stall, and enhances the kinetic energy of the chordwise flow to overcome the adverse pressure gradient to suppress flow separation and promote flow reattachment. Under the condition of Mach number 0.283, reducing frequency 0.151 and advance ratio 0.25, CFJ can increase the lift of the airfoil, reduce the drag and the negative pitching moment peak, and advance the reattachment of the flow. The overall aerodynamic characteristics of the airfoil are obviously improved by the CFJ control.