Effects of Geometrical Parameters on Performances of Wind Energy Harvester with a Chamber

Abstract

To improve the performances under low speed wind, a wind energy harvester similar to harmonicas was proposed. The harvester mainly includes a cuboid chamber and a cantilevered beam. The front wall of the chamber is opened as the air entrance and a rectangular hole is opened on the sidewall as the exit. The cantilever composed of a piezoelectric sheet and a flexible beam was fixed onto the sidewall of the chamber near the exit. Experimental results show that the width and height of the chamber significantly affect critical wind speed and output power, respectively. The initial attack angle of the cantilever has important influence on the critical wind speed. Blunt body at the air entrance could remarkably decrease the critical wind speed. For a prototype with a 60 mm×20 mm×13 mm chamber, the length of the cantilever of 30 mm and the length of the piezoelectric sheet of 8 mm, the measured maximum output power is 1.1 mW under 17 m/s wind.