Enhancing Vertical Axis Wind Turbine Performance Using Winglets

Vertical Axis Wind Turbines (VAWT) are currently viewed as promising renewable energy sources. However, they are still insufficiently investigated and implemented. H-Blade VAWT specifically are considered very advantageous, but they suffer from induced drag generated from the vortical flow at the tips of the airfoil. This paper suggests winglets as a design solution capable of managing the vortical flow. Winglets have found much use in the aviation industry as they can simultaneously reduce the induced drag and increase the lift. These features can also be harnessed in wind turbines, enabling enhanced power production and improved rotor starting ability. A H-Blade VAWT, with winglets attached to the tips, is proposed to investigate its aerodynamic performance. For this purpose, a Double Multiple Stream Tube (DMST) model has been carried out at first using the QBlade software to examine the performance of the turbine within various design variations. It has allowed us to obtain an optimized turbine structure with attached winglets. This design has then been investigated using Ansys Fluent 17.2 where an unsteady turbulent fluid flow based on the RANS equations and shear stress transport formulations SST k-ω is adopted. The results showed the advantage of adding winglets to the blades in terms of flow regulation, vortices control and power enhancement.