Galloping-based energy harvester considering enclosure effect

Abstract

A galloping-based energy harvester, which is surrounded by structure(s) such as an enclosure, has an aerodynamic force change due to a change in flow caused by movement of the bluff body against the structure(s). Therefore, any model derived without considering this effect cannot predict the harvester’s behavioral or energetic characteristics accurately. The main goal of this study was to develop a model that could be used to accurately simulate a galloping-based energy harvester surrounded by an enclosure. To consider the effect of the enclosure on the aerodynamic force applied to the bluff body, a bivariate quasi-static aerodynamic force model was newly proposed, which was accomplished by performing an experiment involving two variables, the attack angle, and the distance from the nearest wall of the bluff body. A set of governing nonlinear field equations reflecting this force model were derived, and their perturbed solutions were obtained and validated by comparison with experimental results. The effect of the enclosure on the performance of the present energy harvester system was investigated and discussed using both theoretical and experimental methods.