Numerical study of two and three bladed Savonius wind turbine

The aim of this paper is to compare aerodynamic characteristics of two and three bladed Savonius rotor with different overlap ratios by numerical analysis. The models with 0%, 20%, and 30% overlap having the same blade diameter and height are used for the comparison. To ensure the simulation model was correct the results obtained from the CFD were compared with experimental results. The established simulation model was used to find the static torque coefficients and power coefficients to analyze the aerodynamic performance of the taken geometries. From the analysis it was found that rotor with less blade number produces higher torque. It was also found that the rotors with no overlap produces negative torque and the introduction of overlaps in the rotor eliminates the negative torque. Another finding from the analysis is the increase in Reynolds number increases the static torque in the rotor.