Investigating the Effects of Leading- and Trailing-Edge Shapes of a Flapping Wing on Power Extraction Performance

Flapping wings present a promising approach to harnessing energy from fluid flow by leveraging a synchronized pitching and heaving motion of the airfoil. The impact of modifying the leading and trailing edge shapes of a flapping wing on energy harvesting performance is investigated using sinusoidal pitching motion. The pitch angle varies between 80° and 90°. The wing thickness (T1) varies from 8% to 48% of the chord length, with a flat plate chord length of c = 1.0. A promising airfoil profile is achieved by increasing only the leading-edge thickness to 32% of the chord, significantly enhancing energy capture by improving the generation of pushing forces and power. The results show that a wing configuration with a semicircular leading edge and a rectangular trailing edge outperforms the baseline case (a rectangular flat plate) and all other configurations under the same conditions. This configuration shows a notable improvement in power output and efficiency at a pitch angle of 85° and a leading-edge thickness of 32% of the chord. The maximum power output (Cpt) represents a 16.73% increase over the baseline, while the maximum efficiency (η) reflects a 12.77% improvement. These findings highlight the superior energy extraction performance of the new configuration, emphasizing the dominant role of the leading edge in enhancing energy harvesters compared to the trailing edge.