Abstract: Banki wind turbine is a small wind turbine which is suitable for running at low wind speeds, but its overall efficiency is low because of the negative torque in the windward direction. An improved Banki wind turbine with an arc-type deflector baffle arranged in the upwind direction is proposed. In order to investigate the influence of the deflector baffle on the aerodynamic performances and power generation of the turbine, the two-dimensional unsteady flow of the turbine is computed by using sliding mesh. The results show that the deflector baffle can be used to reduce negative torque on the blades in the upwind half cycle, and the power coefficient of the turbine can be increased by 66.9%.

Key words: fluid mechanics, Banki wind turbine, deflector baffle, tip speed ratio