A flow-induced vibration energy harvester based on bioinspired shell surface bluff body

Abstract

The bluff body is integral to a flow-induced vibration (FIV) energy harvesting system, with its aerodynamic characteristics tunable via a biomimetic metasurface. This paper proposes a FIV energy harvester utilizing a bioinspired metasurface to enhance energy harvesting performance. The mathematical model of the proposed FIV energy harvester is developed. Lift and drag coefficients are determined through numerical simulation using COMSOL. The corrugated metasurface reduces the average drag coefficient by 97.5 % and increases lift amplitude by 105 %, while the oblique stripe surface enhances drag by 106.9 % and lift amplitude by 99.3 %. Prototypes of the FIV energy harvester with bioinspired metasurfaces are fabricated and validated in a wind tunnel experimental system. Numerical and experimental results demonstrate that the performance of FIV energy harvesters can be either suppressed or enhanced by employing a bluff body with a bioinspired metasurface. At 0.5 m/s, the corrugated surface boosts output voltage by 94.24 %; at 6 m/s, the straight stripe surface achieves a 106.64 % increase. The oblique stripe metasurface improves peak voltages by up to 287.75 % at higher wind speeds. The operation bandwidth of the FIV energy harvester with a straight striped metasurface bluff body increased by nearly 277 % compared to the traditional smooth body, providing a practical method for harnessing wind energy across diverse natural environments and adapting effectively to fluctuating wind conditions.