Effect of Horizontal and Vertical Overlap on the performance of two-bladed Vertical Axis Wind turbine

Abstract

Harnessing wind energy is one of the cleanest forms and abundantly available to generate electricity. Wind turbines produce electricity from the wind power to drive the electric generators. There are two types of Wind turbines depending on the axis of rotation with the respect to the ground, Horizontal axis wind turbines (HAWT) and Vertical axis wind turbines (VAWT). In urban areas, due to the space compatibility and skewed wind conditions, VAWT are preferred. There are two types of VAWT, lift-type configuration like Darrieus wind turbine and drag-type configuration like Savonius wind turbines. Due to factors like self-starting capabilities and better performance even in low-speed winds, Savonius wind turbines are preferred. The present paper, Effect of Overlap Ratio on the blade performance are investigated and analysed. For this, the diameter of the rotor is maintained. Two dimensional numerical simulations are performed using RANS equations and sliding-mesh method. The turbulence model employed is SST k- ω model. Change in the RPM due to overlap distance at various inlet wind speeds were analysed and compared. The performance of zero overlap ratio and optimal mode at overall overlap ratios are compared.