Performance Evaluation of a Savonius Wind Turbine with Morphing Blades

Analysis of a novel flexible blade with the ability to morph and adapt to changing flow conditions is presented in this paper. The concept is applied to a novel rotor geometry with spline function, which is derivative of the traditional S-shape Savonius blade, explored in a previous study by the authors. A Fluid Structure Interaction algorithm, implemented in ANSYS CFX 12.1 and ANSYS Mechanical 12.1, is used to estimate the turbine performance by varying Young’s modulus and monitoring blade tip displacement. Since the Savonius wind turbine has a vertical axis of rotation, the centrifugal forces are an issue because of their high magnitude. Therefore, an effective morphing process is simulated in this study by first neglecting inertia forces. It was registered that, when inertia forces are considered, centrifugal forces tend to overwhelm aerodynamic forces bending both blade tips outward. Alterations to the design are proposed in this paper to account for this negative effect of centrifugal forces, thus validating the initial hypothesis regarding the superior performance of adaptive blades.