Synergistic analysis of a wake galloping piezoelectric energy harvester coupled with a DC interface circuit

Since wake galloping piezoelectric energy harvesters (WGPEHs) are inherently multi-physics coupled systems, theoretical performance analysis remains challenging due to the disconnect between fluid-structure interaction and circuit-level analysis. This work proposes an innovative equivalent circuit modeling (ECM)-based framework for multi-physics analysis of WGPEHs, offering the flexibility to integrate any interface circuit directly into the simulation. In the proposed approach, the aerodynamic force acting on the WGPEH is first characterized through CFD simulations. The mechanical dynamics are then translated into an equivalent circuit using mechanical-electrical analogies. In this study, a WGPEH based on a tandem cylinder configuration is designed, fabricated, and experimentally tested in a wind tunnel under various conditions. CFD simulations and flow field analysis are performed to characterize the wake galloping aerodynamic force. Based on these results, an equivalent circuit model of the WGPEH is developed and validated by comparing its output with experimental and CFD simulation results. To further demonstrate the flexibility of the approach, a rectifier bridge circuit for AC-DC conversion is incorporated within the ECM framework. The results confirm that this modeling strategy can not only accurately predict the output performance of the WGPEH but also accommodate complex interface circuits. This work provides a new and effective pathway for the comprehensive analysis and design of wake galloping energy harvesters.