No abstract

The Savonius-conventional wind turbine is a class of wind turbines designed with a vertical axis. It has a good starting capacity and   an insensitivity to wind direction. It works relatively at low wind speed in an easy installation. Savonius wind turbine faces major drawbacks, including some of the low efficiency and high negative torque created by the returning blade. Many attempts have been undertaken to optimize the blade’s shape to increase the performance of these wind turbines. The vertical axis is still under development. The elliptical-blades with a cut angle equal 47.50° have recently shown enhanced performance. In this study, we investigate the effect of Elliptical-bladed multistage Savonius Rotors (rotor aspect ratio, stage aspect ratio) on the performance by means of numerical simulation. The results obtained by comparison of one, two, and three-stage rotors indicate that the maximum power coefficient increase with a number of the stages (for the rotors with similar RAR of 0.7). Moreover, for the rotors with similar SAR of 0.7, the two stages have the highest performance than others.©2020. CBIORE-IJRED. All rights reserved

No abstract

The classic Savonius semi-circular blade turbine has a relatively low power coefficient.The performance of a Savonius wind turbine depends on its geometrical parameters. Various blade profiles have been developed in the past years to improve the performance of this class of turbine. In this paper, a new blade shapes of Savonius wind turbine is investigated numerically by using the CFD method , by using transient conditions and set k omega turbulence model.The new blade has different concave and convex shape, which is a combination of the conventional and the elliptical blade. A comparative study of three blade profiles, semi-circular, elliptical and the composed blades have been performed.Flow structures around the rotor have also been analyzed. The results show that changing the blade shape has an effect on the performance efficiency of the Savonius turbine.The new modified and the elliptical blade exhibit higher performance compared to the conventional Savonius wind turbine. The new modified Savonius blade and the elliptical blade exhibit an improved performance compared to the conventional model in the order of 20.5% and 18.2% respectively at the tip speed ratio of 0.8.