Effect of Leading Edge Tubercles on Vortex Dynamics of Periodically Pitching Swept Wings

Leading Edge Perturbations (LEP) on Humpback Whale Flippers have been the inspiration behind airfoil modification since the early 2000s. These spherical and wavelike structures at the tip of whale flippers enable these huge creatures to make swift maneuvers to catch their prey. Past computational and experimental studies of airfoils with LEPs showed delayed flow separation and drag reduction at high angles of attack. This is attributed to segmentation of flow and opposing vortices being formed at the wing tips that cause an increase in momentum transfer inside the boundary layer and a delay in flow separation. LEPs have a potential to be used in Micro Air Vehicles in which airfoils exhibit pure pitching movement to generate thrust. Using low-resolution DNS simulations, a 32.1% improvement in thrust coefficient and a substantial 33.3% increase in lift coefficient have been recorded in this study, underscoring the significant performance enhancements achieved through the incorporation of leading-edge tubercles in pitching swept wings.