Numerical study of the effect of geometry and operating parameters on the performance of Savonius vertical axis wind turbine

The Savonius turbine is a vertical axis wind turbine (VAWT) suitable to be mounted on rooftops of highrise buildings. It is a viable technology for power generation. The operating parameters and rotor design have a significant effect on the performance of VAWT. We have studied the effects of various parameters such as number of blades, blade arc angle, overlap ratio and gap width ratio on the performance of VAWT. Data from the literature have been reviewed for completeness. Two-dimensional numerical study subjected to a thorough grid independence study was conducted using ANSYS Fluent 15.0, and the results have been validated. The results show that the rotor system with two-blade arrangement performs better at tip speed ratio of 0.8. The rotor with gap width ratio of 0.15 and blade arc angle of 180 degrees was found to perform better at a wind velocity of 7 m/s. Overlap ratio and modifications in the blade were found to have a negative effect on the performance.