Enhancement of FIV-based energy harvesting in bladeless wind turbines through downstream obstacle

This study proposes a modified flow-induced vibration-based energy harvester. To accomplish this objective, a bluff body inspired by nature is complemented by a second fixed body, and its impact is examined. This research is focused on theoretical and experimental studies of approaches to increase fluid induced vibration. To do so, a comprehensive examination of the near-wake flow using particle image velocimetry is conducted. Subsequently, the electromechanical equation of motion for the vibration-based energy harvester utilizing piezoelectricity is derived. Then, a series of wind tunnel experiments are conducted to prove the positive effect of the downstream rectangular plate and its impact on the energy harvester efficiency. Results show that the proposed changes in the energy harvesting system can effectively increase the amount of produced energy. In order to improve the merging of vortices over the bluff body, the so-called nondimensional distance is defined and investigated. It has been demonstrated that utilizing the system with optimal parameters can improve the output voltage by more than 80% and consequently increase the efficiency of the system.