Starting torque improvement using J-shaped straight-bladed Darrieus vertical axis wind turbine by means of numerical simulation

•A new approach is studied in order to modify VAWTs performance and starting torque improvement.•In this approach, the J-shaped profiles are used as the blade airfoil in the structure of the blades.•J-shaped profiles is designed by means of eliminating the pressure side of Du 06-W-200 airfoil from the maximum thickness.•Wind turbines operate on the lift force or drag force, J-Shaped profile utilizes lift and drag forces simultaneously.•The results obtained indicate that the wind turbine performance is improved and the starting torque is magnified using J-Shaped profile.

In this study a 3 kW straight–bladed Darrieus type Vertical Axis Wind Turbine (VAWT) is investigated numerically using OpenFOAM computational fluid dynamic package. The newly proposed J-Shaped profile is used as the blade airfoil in the simulation. The J-Shaped profile is designed by means of eliminating a fraction of pressure side of Du 06-W-200 airfoil. The main purpose of this investigation is the improvement of the VAWT starting torque using J-shaped profile. The power curves for both conventional and J-shaped profiles are calculated and the torque variation is obtained at different azimuth angles. In addition, the vorticity and pressure field surrounding the wind turbine is presented. The results indicate that the performance of turbine is optimized for J-shaped profile which eliminates the pressure side of airfoil from the maximum thickness toward the trailing edge. Moreover, by employing this J-Shaped profile, the wind turbine performance is intensified TSRs and self-starting of turbine is improved.