Self-start capability is an important feature of wind turbines. The present paper aims to improve Darrieus turbine blade performance at start-up by using a blade arrangement. Numerical flow analysis yielded the values of the NACA4415
lift and drag coefficients for impacts ranging from incidence -40° to 40° for several azimuth positions. Geometry with vortex generators and continuous blowing jets as passive and active controls has been tested, and the Reynolds-averaged Navier-Stokes equations were solved. Using the ANSYS CFX calculation code and realizable k-ε turbulence model, a tetrahedral mesh was employed to treat the flow character around an asymmetrical profile NACA4415, and the results were validated by wind tunnel measurements. The impact of several parameters (vortex generator position, span-wise distance for blowing) on the aerodynamic performance of the blade was studied. According to the investigation results, the optimal position for vortex generators was selected upstream of the separation zone at 0.35 c. Moreover, the blade performance at start-up was greatly enhanced when lowering the distance between the blowing holes.