Shan Xiaobiao, Tian Haigang, Cao Han, Feng Ju, Xie Tao
State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001, China.
Micromachines (Basel). 2020 Jul 26;11(8):725. doi: 10.3390/mi11080725.
This paper presents a novel airfoil-based piezoelectric energy harvester (EH) with two small square prisms attached to an airfoil. This harvester can achieve a two degree-of-freedom (DOF) plunge-pitch motions. Several prototypes of energy harvester were fabricated to explore the nonlinear aerodynamic response and the output performance in a wind tunnel. The experimental results showed that the longer the flexible spring was, the lower the critical velocity and frequency of the harvester were, and the better aerodynamic response and output performance could be achieved. The initial disturbance, the following limit-cycle oscillation, and the ultimate chaos of nonlinear response occurred, as increasing airflow velocity was increased. The overall output performance of the harvesters with a flexible spring having a thickness of 1 mm outperformed than that of the harvesters with a flexible spring having a thickness of 0.5 mm at a higher airflow velocity, while the tendency was opposite at a lower velocity. An optimum output voltage of 17.48 V and a power of 0.764 mW were harvested for EH-160-1 at 16.32 m/s, which demonstrated it possessed better performance than the other harvesters. When the capacitor was charged for 45 s and directly drove a sensor, it could maintain working for 17 s to display temperature and humidity in real time.
本文提出了一种基于翼型的新型压电能量采集器（EH），该采集器在翼型上附着了两个小方柱体。这种采集器能够实现二自由度（DOF）的沉浮-俯仰运动。制作了多个能量采集器原型，以探究其在风洞中的非线性气动响应和输出性能。实验结果表明，柔性弹簧越长，采集器的临界速度和频率越低，气动响应和输出性能越好。随着气流速度增加，出现了非线性响应的初始扰动、后续极限环振荡以及最终的混沌现象。在较高气流速度下，柔性弹簧厚度为1mm的采集器的整体输出性能优于柔性弹簧厚度为0.5mm的采集器，而在较低速度下趋势相反。EH-160-1在16.32m/s时收获了17.48V的最佳输出电压和0.764mW的功率，这表明它比其他采集器具有更好的性能。当电容器充电45s并直接驱动一个传感器时，它可以持续工作17s以实时显示温度和湿度。
