Piezoelectric energy harvesting from wind-induced vibration under the interference of the double-casement window-like baffle

The exploration of miniature piezoelectric wind energy harvesters has garnered considerable attention as a means to fulfill the autonomous powering demands of wireless sensor networks. The study presents piezoelectric energy harvesting from wind-induced vibration under the interference of the double-casement window-like baffle (DW-PWVEH). By adjusting the opening angle of the baffle, the flow field distribution can be flexibly modulated, thereby regulating vibration amplitude of the bluff body and enhancing the power generation capability of the DW-PWVEH at low wind speeds. CFD simulation and experimental tests confirm the feasibility of the harvester. The results demonstrate that the opening angle and position of the baffle (with a length-to-height ratio of 4:7) significantly influence the output performance of the DW-PWVEH. Appropriately increasing the opening angle enhances vibration of the bluff body at low wind speeds while suppressing its amplitude at high wind speeds. Under conditions of an opening angle θ = 30°, a distance-diameter ratio α = 0.56 (the ratio of the distance between the baffle and the bluff body to the diameter of the bluff body), and a length ratio β = 0.43 (the ratio of length between piezoelectric vibrator and cantilever beam), the maximum output voltage achieved is 37.5 V, with a cut-in wind speed of 0.6 m/s. The power output of a single piezoelectric transducer reaches 0.41 mW, which can continuously supply power to about 100 LEDs in series and power electronic thermometers and LED screens. This research holds significant implications for enhancing the energy harvesting efficiency of flow-induced vibration-based energy harvesters.