Abstract
The authors have proposed the superior wind turbine generator, which is composed of the tandem wind rotors and the double rotational armature type generator without the conventional stator. The large-sized front wind rotor and the small-sized rear wind rotor drive respectively the inner and the outer armatures of the generator, in keeping the rotational torque counter-balanced. Such operating conditions enable to make the output higher than the conventional wind turbine and to keep the output constant in the rated operating mode without using the brake and/or the pitch control mechanisms. In order to get the best performance, the authors started preliminarily optimizing the rotor profiles. This paper discussed experimentally the desirable arrangement between two-stage wind rotors and numerically the flow conditions around the wind rotors. The flow interaction between the front and the rear wind rotors affects not only the flow conditions but also the axial distance between both wind rotors giving the maximum output.