On the effect of slotted blades on Savonius wind generator performances by CFD analysis

In this paper a new bucket configuration for Savonius wind generator is proposed. With theaim to increase the effect of the overlap ratio RS on the wind turbine performances and to increase theamount of lift force able to produce torque and power, slotted blades are investigated by means of theComputational Fluid Dynamics analysis. The numerical analyses are performed by ComsolMultiphysics® and the results obtained for a Savonius wind turbine with overlap only are compared tonumerical and experimental benchmarks. Parametric analyses are performed, for fixed overlap ratio,by varying the slot angle β and the results show that for low angle β the Savonius rotor exploitsimproved performance at low tip speed ratio λ, evidencing a better starting torque. This circumstanceis confirmed by the static analyses performed on the slotted blades in order to investigate the startingcharacteristic of the proposed Savonius wing generator configuration.