Investigating the effect of surface protrusions on galloping energy harvesting

This Letter explores the potential effect of implementing different surface protrusions on galloping energy harvesters. Three types of protruded bluff bodies with rectangular, triangular, and elliptical metasurfaces are proposed, and four kinds of surface treatments are deployed to vary their protruded shape. Wind tunnel experiments reveal that adding the protrusions can obviously change the mode of oscillations, and only the backward protrusions can enhance the galloping response. Both the experiments and simulations show that elliptical surface protrusions have the greatest potential to enhance the galloping energy harvesting performance. Specifically, with a backward protruded length of 15 mm, the maximum output power in the experiments is measured to be 0.757 mW, which occurs at 5.1 m/s, and an optimal load resistance of 300 k?. In this case, the energy harvester outperforms its counterpart carrying a simple square prism by 157.48%.

Automated summary

This Letter examines the potential impact of different surface protrusions on galloping energy harvesters. Three types of protruded bluff bodies with rectangular, triangular, and elliptical metasurfaces are proposed, and four surface treatments are used to modify their protruded shape. Wind tunnel experiments show that the protrusions can significantly alter the oscillation mode, and only backward protrusions can enhance the galloping response. Both experiments and simulations indicate that elliptical surface protrusions have the greatest potential to improve the galloping energy harvesting performance. Specifically, with a backward protruded length of 15 mm, the maximum output power in experiments is measured at 0.757 mW, occurring at 5.1 m/s and an optimal load resistance of 300 k?. In this case, the energy harvester outperforms its counterpart carrying a simple square prism by 157.48%.