Abstract
A new three-stage Savonius windmill rotor, buckets of which have 120-degree phase shift between the adjacent stages, was made. The static torque and the dynamic torque characteristics of the different-phase-type rotor and another type rotor with no phase shift (same-phase type) were measured by the wind tunnel experiments and compared. It became clear that the torque variation of the different-phase type rotor was smoothed and the characteristic in starting was improved. The influence of twelve guide vanes that were attached around the rotors was observed in the torque variation. And the influence was remarkable in low wind velocity or high rotation states.
