An enhanced galloping-based piezoelectric energy harvester with non-rotational bluff body

This study proposes a bluff body non-rotational galloping-based piezoelectric wind energy harvester (BNRGH) for overall output performance enhancement. The bluff body used in this structure is designed to be available to rotate with respect to the free end of two cantilever beams by the connection of rotatable hinges. A series of performance comparisons are conducted experimentally in a wind tunnel between the proposed structure and the conventional galloping-based piezoelectric energy harvester, which commonly configured with a single beam. The results show that the proposed structure is capable of preventing the variation of the attack angle due to the self-rotation of the bluff body caused by the deflection of a common single beam, thus avoiding the amplitude saturation of the bluff body at a higher wind velocity range. It shows that the output voltage remains a continuous linear increase within elastic deformation range of the cantilever beam even in higher wind velocity range, which is helpful in accomplishing a broad wind range for a significant improvement of the overall performance. Overall, the proposed BNRGH provides a design guidance for a small size galloping-based energy harvester to achieve an excellent output performance, which holds great potential to promote its application in wireless node networks for self-power supply.