Abstract
As a method to utilize wind energy effectively, the improvement of wind turbine efficiency was tried by a propeller wind turbine shrouded a casing (a straight pipe) and installed brim backward based on structure of a shrouded wind turbine equipped with a brimmed diffuser and let the wind velocity in a casing have an increase speed by an effect by brim in this study. In an experiment, the good shape of casing and brim was clarified by changing a shape of casing and brim, and the result that windmill efficiency improved was provided. Furthermore, it is thought that can be expected improvement of wind turbine efficiency by designing and using wind turbine blade which is suitable for a wind turbine with brim.
