FLUID DYNAMIC PERFORMANCE AND PERFORMANCE ANALYSIS OF A NOVEL FLEXIBLE OSCILLATING WIND TURBINE

Abstract

While the variable pitch angle design has been proven to significantly enhance the performance of vertical axis wind turbines, its implementation requires the addition of extra mechanical devices, such as a chain-and-sprocket system. These additional mechanisms not only increase system friction and produce extra vibrations but also cause vertical axis wind turbines to lose their omnidirectional characteristics. To address this issue, this study proposed a novel flexible oscillating wind turbine, wherein the function of changing the pitch angle is accomplished through the deformation of flexible blades. To reveal the internal flow field mechanism of this novel turbine, particle image velocimetry experiments were conducted. The results indicate that the flexible blade can alter its posture to form a suitable angle of attack under different azimuth angles. In the downstream region, the blades spread out to generate a substantial positive torque. In contrast, in the upstream region, the blades are in a diversion state, always maintaining a small angle of attack to avoid generating excessive negative torque. Wind tunnel experiments were carried out on the flexible oscillating wind turbine to explore the effects of wind speed and key geometric parameters on the turbine’s performance. The results show that the novel flexible oscillating wind Turbine maintains high efficiency even under low wind speed conditions.