Design and Characteristic Analysis of a Performance-Enhanced Piezoelectric Wind Energy Harvester With a Transformable Y-Type Bluff Body

The current vortex-induced vibration (VIV) piezoelectric wind energy harvesters (PWEHs) have a narrow operating wind speed range, while galloping piezoelectric energy harvesters are at risk of damage from excessive amplitude at high wind speeds. Addressing these issues, a novel performance-enhanced PWEH (PEPWEH) with a transformable Y-type bluff body has been proposed. The alteration of the transformable Y-type bluff body shape effectively modifies the shedding characteristics and intensity of vortices at a micro level, subsequently influencing the vibration mode and output voltage of the energy harvester at a macro level. The vibration mode of the energy harvester transitions from galloping to coupled vibration, ultimately transforming into VIV. The structure and working principle of the energy harvester are introduced, and the modeling, simulation, and experiments are studied. When the proof mass is small and the windward angle is between 60° and 180°, it is beneficial to reduce the onset wind speed, increase the voltage, and widen the effective operating bandwidth. A larger length ratio and a flexible wing thickness of 0.3–0.45 mm can extend the coupled vibration time. The peak output power is 0.26 mW at a load of 500 k
$\Omega $
and a wind speed of 10 m/s. Moreover, the energy harvester demonstrates the prolonged power generation capability of signal transmitters and 100 LED lights.