A magnetic excitation galloping piezoelectric energy harvester with fish-scale protrusion convex bluff body

This paper investigates a magnetic excitation galloping piezoelectric energy harvester based on a fish-scale-protrusion-shaped convex bluff body. It innovatively adopts a metasurface structure with a square bluff body with fish-scale protrusions and combines a magnetic coupling excitation mechanism to optimize device performance. A fluent three-dimensional computational fluid dynamics simulation is utilized. The vortex shedding intensity and lift coefficient of the triangular, ordinary square, and square bluff bodies with fish-scale protrusions are compared to verify the optimization effect of the fish-scale protrusions on the airflow distribution. Subsequently, an experimental platform is established. This research primarily centers around the interaction mode (attraction/repulsion) between fish-scale protrusions and magnets, as well as the influence of cantilever beam thickness (0.3, 0.4, and 0.5 mm) on the output voltage of the device. The experimental results show that, for this device, at a critical wind speed of 2 m/s, a square bluff body with fish-scale protrusions can achieve a voltage of 6.04 V, thereby expanding the bandwidth. At a wind velocity of 6 m/s, a cantilever beam measuring 0.4 mm in thickness and the magnet in an attracting state, the peak output voltage attains 38.08 V. The highest output power achieved is 2.439 mW. The device can effectively charge capacitors and light up 19 light-emitting diodes.