Enhancement of Vibration Energy Harvesting Performance by Omni-Directional INVELOX Wind Funnel: A Computational Study

Abstract

An alternate renewable energy source, through a piezoelectric vibration energy harvester with a bluff splitter body, could lead to higher efficiency in energy harvesting, through vortex-induced vibration at a near-resonance condition at 20 m/s high wind speed. However, wind energy is not as popular as solar energy, as the main renewable energy source in Malaysia, due to the relatively low wind speed available in the country. The INVELOX machine, introduced in 2014, was one of the most recent systems used to harvest wind power by accelerating wind speed. This omni-directional wind funnel could capture wind from all directions and tunnel it through a convergent-divergent nozzle, where the coupled bluff splitter body and piezoelectric vibration energy harvester (PVEH) are located at its venturi throat, which could lead to an increase in wind speed to fulfil the task of VIV energy harvesting. The proposed modified design is found to achieve 2.7 times the wind speed amplification at the venturi, which outperformed previously proposed designs. To achieve the optimum wind speed of 20 m/s for the coupled bluff splitter body and the PVEH plate, a free-stream wind speed of 7.4 m/s is recommended. The integration of the PVEH plate and the wind funnel is expected to harvest maximum voltage output at 20.99 V or 4.96 V, with a maximum power output of 0.82mW at 20 m/s.