Impact of Slotted Blade on the Flow Field of Straight-Bladed Vertical Axis Wind Turbines

The straight-bladed vertical axis wind turbine (SB-VAWT) faces challenges such as difficulty in startup and low wind energy conversion efficiency, which restrict the development of SB-VAWTs. In this paper, the aerodynamic performance of SB-VAWT is improved with a custom-designed internal slot on the blade, and the vortex distribution is analyzed through Liutex processing. For SB-VAWTs, flow separation occurs at large angles of attack, significantly reducing wind energy conversion efficiency. Using ANSYS-FLUENT, this study conducts three-dimensional numerical simulations on various slotted blade configurations for the NACA0018 airfoil. Subsequently, Liutex processing is applied to obtain detailed vortex distribution patterns from the simulation results. The results indicate that the internal slot on the blades can transfer the flow from the pressure side to the suction side, effectively delaying flow separation at large angles of attack. In the wake region, flow field analysis reveals that the turbulent kinetic energy of the grooved airfoil is significantly reduced compared to the original airfoil, leading to improved aerodynamic performance. This study's conclusions have played a positive role in enhancing the aerodynamic performance of SB-VAWT, providing valuable insights for future developments in this field.