Enhanced performance of piezoelectric wind energy harvester by a curved plate

Abstract

Piezoelectric wind energy harvesting is a promising strategy for developing self-powered small electromechanical systems. In this paper, a curved-plate bluff body is studied for enhancing the performance of piezoelectric wind energy harvester based on galloping phenomenon. The proposed curved-plate bluff body seems to have more design flexibility and the possibility of improving aerodynamic performance. A lumped parameter theoretical model is given and verified by experiments. The numerical research has shown that the curved-plate bluff body can obtain high lift and negative pressure in the inner circulation, which are the key drivers for the vibration of the piezoelectric beam based on galloping phenomenon. Experimental results show that the piezoelectric wind energy harvester with the curved-plate bluff body (WEHC) can generate higher output voltage than the conventional cross-section (square, regular-triangle, and D-shaped) bluff bodies, and has a lower cut-in wind speed. When an external load resistance of 820 KΩ is connected and the arc length is 45 mm, the piezoelectric wind energy harvester with curved-plate bluff body generates an average power of 35.6 μW.