Enhancing the Performance of an Oscillating Wing Energy Harvester Using a Leading-Edge Flap

In this study, we investigated the power generation capability of an oscillating wing energy harvester featuring an actively controlled flap positioned at the wing's leading edge. The findings revealed that attaching a leading-edge flap reduces fluid flow separation below the wing's lower surface at the leading edge, resulting in smoother flow and increased velocity near the hinge region. The leading-edge flap increases the pressure difference across the wing's surface, thereby enhancing the overall performance. In addition, the introduction of the leading-edge flap effectively elongates the wing's effective projected length in the heaving direction, leading to increased thrust. We examined flap lengths ranging from 10% to 50% of the chord length, with the maximum pitch angles of the wing and flap varying from 75 degrees to 105 degrees and 30 degrees to 55 degrees, respectively. The optimal power generation was achieved using a flap length of 40% of the chord length, combined with maximum wing and flap pitch angles of 95 degrees and 45 degrees, respectively. These conditions yielded a 29.9% overall power output increase and a 20.2% efficiency improvement compared to the case without the leading-edge flap.