Evaluation of output performance of vertical axis wind turbines equipped with Magatama blades

Magatama blade has been proposed as a blade specialized for vertical axis wind turbine (VAWT). Cross section of the blade has been investigated by using Genetic Algorithm (GA) by authors to improve its performance. In this paper, performance of VAWT with the Magatama blade is experimentally investigated. As a first step, wind tunnel experiments are conducted with a small scale VAWT model at low tip speed ratio condition. Results show that power coefficient CP of the improved Magatama blade increases at any tip speed ratio λ. Performance tests with large scale VAWT model are then conducted at open-air facility at relatively large tip speed ratio condition. In this field experiment the performance of the Magatama VAWT were compared with that of conventional VAWT with NACA0018 blade. Results show power coefficient CP of the Magatama VAWTs are larger than that of conventional VAWT with NACA0018 blade.