Performance enhancement of galloping wind energy harvesting via bio-inspired V-shaped blade

Galloping wind energy harvesting has promising applications in future distributed self-powered low-power devices. A novel V-shaped blade is figured out from Palm leaf galloping. The enhancement of galloping oscillation from the bio-inspired V-shaped blade is evaluated. The galloping wind energy harvester (WEH) with a V-shaped blade is developed by electro-mechanical modeling, finite element simulation, ground vibration tests, and wind tunnel tests. It is found that the structural damping, effective electro-mechanical coupling coefficient, and V-shape included angle have big effects on the harvesting performance. The cut-in wind speed of WEH is below 3 m/s. With an included angle of 115° and a wind speed of 6.5 m/s, the output voltage is 4.48 V and the power density is 90.00 μW/cm³. The V-shaped blade harvester exhibits a 151.69% increase in output voltage and a 575.00% increase in power density compared to the traditional brick blade (square cross-section) harvester. Tests indicate that the output frequency remains stable at the structural resonant despite increasing wind speed. This study provides insights into enhancing galloping oscillation and wind energy harvesting efficiency by optimizing the aerodynamic shape of vortex shedding bluffs.