Microtab for performance improvement on a vertical-axis wind turbine at high tip-speed-ratios

In this study, the effect of microtab (MT) with different deployed positions and heights on the performance of a vertical-axis wind turbine (VAWT) is investigated through two-dimensional CFD simulation. The simulation results show that optimum deployed position for better turbine performance is 96% of chord from leading edge and optimum height is 0.5% of chord, which makes the power coefficient of turbine increase by 13% at TSR = 3.2. The observation of flow fields around turbine blade with MT indicates that MT decreases area of stall region at azimuthal angles ranging from 90° to 270°, leading to the increase of pressure and torque of turbine blade. The simulated results demonstrate that MT is an effective solution to enhance flow characteristics around turbine blade and improve turbine performance at high tip-speed-ratios.