Application of guide blades for improving performance of savonius wind turbine

Application of guide blades is an appropriate method for improving aerodynamic performance of savonius wind turbine. Guide blades gather the wind energy around the turbine and guide them into the concave side of savonius rotor. In this paper, numerical investigation is conducted for evaluating effect of the guide blades on the performance of savonius turbine. Aerodynamic performance of the turbine is investigated for different numbers (3, 4 and 5) and angles (30°, 40°, 50° and 60°) of guide blades. Numerical results indicate that the turbine power and torque coefficients are increased significantly by adding guide blades. For a 5-bladed stator with a 30° blade angle, the turbine maximum power coefficient is increased to 0.51 which shows about 183% compared to a conventional single rotor with maximum power coefficient of 0.18. Turbine with 4 and 6-bladed stator design has maximum power coefficients of 0.42 and 0.49 respectively which show an increase of about 133 and 171% in comparison to a conventional single rotor. Power coefficient of the turbine with 5-bladed stator has a bigger optimum range of operation in comparison with 4 and 6-bladed stator design.