Influence of diameter/aspect ratio on the output performance of wake-induced vibration piezoelectric energy harvester

To address the self-powered issue of micro-sensors, an integrated piezoelectric energy harvester was proposed, which utilized wake-induced vibration (WIV). Utilizing the wind-induced vibration energy harvesting test bench and a two-way fluid–structure interaction calculation approach, the output performance of the energy harvester under vortex-induced vibration (VIV)and WIV was compared. The study investigated the effects of wind speed, diameter ratio, and aspect ratio on the output performance of the integrated piezoelectric energy harvester. The response mechanism to WIV was elucidated. The findings indicated that the energy harvester performed more effectively under WIV than under VIV. With a diameter ratio of 1.0, the upstream interfering column exerted an inhibitory effect, resulting in the poorest output performance for the integrated piezoelectric energy harvester. At a diameter ratio of 1.5, the maximum effective power of the integrated piezoelectric energy harvester reached 44.28 μW, a 4.65-fold increase over the previous condition. Based on variations in the aspect ratio, the wake region could be categorized into an extended body region, a reattachment region, and a common shedding region. Within these, the integrated piezoelectric energy harvester demonstrated the best output performance in the reattachment region. These findings provide a theoretical foundation for the application of wake excitation in piezoelectric energy harvesting and offer guidance for advancements in micro-sensor self-powered technology.