Micro-electricity generation from wind-induced vibration with magnetostrictive material-based energy harvester

Abstract

This study aimed to experimentally investigate flow-induced vibration of modified circular cylinders for wind-receiving mast of Vibration-Based Power Generator (VBPG). Specifically, it focused on vibration characteristics of tapered and stepped circular cylinders in VBPG mechanism. Tapering and inverting cylinder model proved effective in reducing Vortex-Induced Vibration (VIV) onset and peak amplitude concerning flow stream velocity. Some tapered cylinder models showed a broadening peak response (upper branch region), showing an extensive power harvesting range for VBPG device. The result showed that the maximum power harvesting of the model with a plain bluff cylinder was 8.45 mW, reduced by tapering bluff cylinder. The power coefficient of VBPG with a normal bluff cylinder was 4 %, but inversing stepped bluff cylinder yielded 5.45 %. It is related to VIV-onset parameter, which was lower than that the plain cylinder. In addition, it was discovered that there was an interdependency between frequency response and power generation capacity for VIV-type resonance. The generated power proved sufficient to illuminate a board with 54 LED lamps in a laboratory-scale test. Meanwhile, an outdoor performance test of harvester, conducted with variable wind speed (0 – 3.2 m/s), showcased the reliability of VBPG mechanism for independent power supply to wireless, remote sensor networks, or moderate scale of power supply. The field test model worked not only in variable wind speed, but also in chaotic wind direction.