Abstract
A wind concentrating tower type wind turbine was developed as a propeller type wind turbine without the mechanism to follow the changing wind direction. The purpose of this study is to understand the optimum cowl shape for the accelerate ratio of wind speed. Several type of cowl shape were used for this experiment, e.g. expansion cowl, contraction cowl, double structure composed of inner cowl and outer cowl and single structure. As a result, it was found that the accelerate ratio of expansion cowl is higher than the accelerate ratio of the contraction cowl.
