Experimental investigation of aerodynamic energy harvester with different interference cylinder cross-sections

Collecting kinetic energy from ambient vibrations for sustainably powering microelectronics becomes favoured in recent years. Yet the distribution of environmental oscillations is generally over a wide frequency spectrum which limits harvesting purpose of current energy harvesters. This work reports an optimal experimental design of piezoelectric energy generator for efficiently harvesting from aerodynamic oscillations. Various cross-sections of an interference cylinder (IC) are proposed so that the designed energy harvester operates under small wind speeds over a wide bandwidth. Average power of 803.4 mu Wat wind speed of 2.36 m/s with spacing ratio of 0.9 for the square interference cylinder configuration is achieved, and the synchronization region is increased 380% compared to that without the interference cylinder. It is observed that the harvester with circular or triangular interference cylinder at a certain value of spacing ratio displays a quenching behavior, resulting in quite a small output average power, which needs to be avoided. Transferring mechanism of dynamic behaviors for the energy generator equipped with an IC is determined and closely related with variations of the vibration frequency. Experimental results show that the plate interference configuration for the energy harvester has a superior harvesting performance over other configurations, especially in the occurrence of vortex induced vibrations. (C) 2018 Elsevier Ltd. All rights reserved.