Abstract
Recently, Ohya et al.have developed an effective wind-acceleration system.Although it adopts a diffuser-shaped structure surrounding a wind turbine like the others previously proposed, the feature that distinguishes it from the others is a large flange attached at the exit of diffuser shroud.A flange generates a large separation behind it, where a low-pressure region appears to draw more wind compared to a diffuser with no flange.Owing to this effect, the flow coming into the diffuser can be effectively concentrated and accelerated.To develop a shrouded wind turbine for higher performance, we tried to find a suitable combination of a flanged diffuser and wind turbine.We made some diffusers and wind blades by using a simple theory for the wind turbine with a flanged diffuser and measured the output power of shrouded wind turbines in a wind tunnel experiment.
