A bi-directional flow-energy harvester

Due to a rapid decrease in fossil fuel resources and ever-growing carbon emissions, clean energy is urgently needed as vital solution. In the past two decades, harvesting from ambient environment has attracted much attention. Flow induced vibration performance of cylinder with fins attached were investigated. Four configurations studied: plain cylinder, windward fins, leeward four fins. These cylinders tested water channel reduced velocity ranging between 2 25 Reynolds number 1500 11 400. It was found that two-windward-fin underwent galloping, exhibiting larger amplitudes broader operational range, whereas two-leeward-fin only weak vortex-induced vibrations. By attaching both bi-directional flow-energy harvester implemented, which outperformed range. More importantly, due geometric symmetry, it able harvest flow opposite directions. A tuned-mass-damper system then four-fin for purpose demonstration. Within current speed maximal voltage power outputs are about 7.37 V 1.81 μW, respectively, 2.7 7.2 times cylinder's peak values. The effects incident angle fin length also studied. Numerical simulations conducted provide detailed information pressure uncover underlying physics. This suitable candidate operate at sites where periodically switches its directions, such tidal flows.