Performance analysis of monostable magnetic coupling downstream plate WIG energy harvester

Using piezoelectricity to harvest wind energy instead of conventional batteries to power small wireless sensors is a promising solution. This study introduces a magnetic coupling downstream plate wake-induced galloping (WIG) piezoelectric energy harvester (MPGEH), with the downstream plate serving as an effective alternative to the magnet pedestal. The feasibility of this structure is demonstrated through Computational Fluid Dynamics (CFD), wind tunnel experiments and numerical model analysis. The CFD results show that the downstream plates affect MPGEH's performance by disturbing the boundary layer separation and shedding of the wake vortices. Wind tunnel experiment results show that the energy harvesting ability is improved by introducing the downstream plate. Additionally, the introduction of magnetic repulsion further reduces the galloping onset wind speed, enhances the maximum of the output voltage and its stability. Moreover, the numerical model constructed can accurately predict experimental results. Under optimal conditions with a load resistance of 0.8 MΩ and a wind speed of 6 m/s, MPGEH with spacing ratio (L/D) = 0.4 and width-to-diameter ratio (W/D) = 1.25 achieves a maximum output power of 4.67E-5 W, representing a 133.5 % improvement over traditional square bluff energy harvester. In summary, this study provides valuable insights into the improving the energy harvesters.