Effect of a semi-cylindrical wind shield on the power output of a vertical axis wind turbine

The effect of a semi cylindrical shell shield on the power output of a vertical-axis-wind-turbine was investigated experimentally. The vertical axis wind turbine consist in a vertical axis with U-shaped blades (Savonius) placed into a semi-cylindrical chamber, closed for a 270⁰ sector, in order to reduce the counter effect of the wind on the turbine blades moving against it. Screening the wind turbine geometry has the advantage of reducing the wind resistance that acts in the opposite direction of the rotation of the turbine. In addition, the air swirl form in the shield shell increase the turbine torque, therefore an increasing of the power at the output of the generator have been obtained. The power output increase with the geometry of the shield installed and depends on the width and height of the turbine, also on the relative position of the shield.