Volume 11 Issue 3 ( September 2024)

The energy demand, which relies on fossil fuels, is increasing while their availability is decreasing. As a result, alternative energy sources like wind energy are necessary to decrease the reliance on fossil fuels. The recent study focused on enhancing the performance of Darrieus H rotor type by attaching Vortex Generators (VGs) to harvest wind energy more efficiently. The study examined a three-blade Darrieus H rotor turbine with rectangular straight VGs under a wind velocity of 8 m/s. The fluid flow characteristics were analyzed using the Unsteady Reynolds Averaged Navier Stokes (URANS) model, and the performance was evaluated using the Coefficient of Power (Cp). The rectangular straight-type VGs were positioned at different chordwise (x/c) locations of 10%, 15%, 20%, 25%, and 30%. The findings indicated that VGs could significantly enhance the turbine's performance, with the most optimal position for the VGs being at x/c of 30%. This positioning produced the highest Cp value of 0.452 at a tip speed ratio (TSR) 1.5. The average Cp improved by approximately 30% compared to a wind turbine without VGs. Visualization of turbulent kinetic energy illustrated how VGs disrupted the flow around the airfoil, acting as flow control to diminish separation. These findings offer valuable insight into using VGs for designing airfoils and utilizing geometric VG parameters for optimal design. Although the improved performance shows potential for harvesting wind energy in low wind speed environments, it's essential to acknowledge that the flow field details may be constrained due to the rotating nature of the turbines.

Keywords: Darrieus Turbine, Vortex, Rectangular, Performance, Tip Speed Ratio (TSR).