Novel piezoelectric wind energy harvester based on coupled galloping phenomena with characterization and quantification of its dynamic behavior

Abstract

In this study, a novel piezoelectric energy harvester is proposed based on coupled transverse and interference galloping to improve the energetic performance of the conventional transverse galloping-based piezoelectric energy harvester. To quantify the stochastic characteristics of the aerodynamic force under the coupled galloping effects, we developed a special approach that allowed us to successfully characterize the aerodynamic force obtained under a transient state and develop a set of coupled dynamic model system. An extensive investigation on the energetic state of the proposed system and its nonlinear behavior revealed the existence of an additional nonlinear damping mechanism. In particular, the associated nonlinear damping force was identified based on the energetic consideration of the proposed system. To the best knowledge of the authors, such a characterization process has not yet been reported. In addition, the dynamic model system was systematically designed by performing an eigen-analysis using the vector operator approach. Furthermore, a perturbation procedure was conducted to obtain the nonlinear limit-cycle behavior of the proposed system. The comparative analysis of the theoretical values derived using the proposed model system with those obtained from experiments revealed that they were consistent with each other, which validated the accuracy of the current modeling approach. When compared to the average electric power harvested from the conventional (transverse) galloping-based piezoelectric energy harvester, the proposed energy harvester generated 20 times more electric power.