A piezoelectric wind-induced vibration energy harvester via the Venturi effect

In this Letter, the Venturi effect is introduced to change the vibration behaviors of a downwind bluff body and a piezoelectric wind-induced vibration energy harvester using the Venturi effect (VE-PWVEH) is reported to offer an alternative solution to enable a high-performance downwind PWVEH. Also, the power generation characteristics were readily adjusted by the flow channel forming the Venturi effect without modifying the PWVEH structure. So, the VE-PWVEH could possess both great power-generating capability at low wind speed and strong robustness at high wind speed. The results demonstrated that both the output voltage and cut-in wind speed were affected by the attack angle of two rectangular plates used for stimulating the constricted channel. There was an optimal attack angle of 60 degrees where a maximum peak voltage of the VE-PWVEH was increased by 621% and the cut-in wind speed was reduced by 171% compared with the harvester without the Venturi effect. Besides, it demonstrated the VE-PWVEH could achieve an output power of 0.863 mW and illuminate about 120 blue LEDs in series. The introduction of the Venturi effect provides a simple and viable method of flow field disturbance to tune the performance of PWVEHs.