Impact of Flexible Blades on the Performance of Savonius Wind Turbine

In this work, elliptically deformable blades are proposed to improve the efficiency of Savonius vertical axis wind turbine. The deformable blade changes its shape during turbine rotation. The elliptic expansion of the advancing blade increases the positive torque and the contraction of the returning blade decreases the negative torque, which improves dramatically the turbine performance. Two-dimensional (2D) numerical model is established using commercial code ANSYS-fluent18.0. The deformation universal mathematical equation is executed within a user-defined function. The study investigated the effect of elliptic mode of deformation as well as the expansion amplitude on the turbine performance. The numerical model is validated against experimental results. Results show that the torque coefficient is improved by about 24% for the lowest expansion amplitude and by about 90.6% for the highest expansion amplitude.