Aerodynamic Impacts of Black-Tipped Wing Coloration on Avian Flight Efficiency: A Bio-Inspired Study

Dark pigmentation near the wingtips of avian wings has been suggested to influence aerodynamic performance through thermally induced changes in near-wall flow behavior. Motivated by these observations, this study investigates the aerodynamic effects of spanwise-localized wingtip heating using three-dimensional computational fluid dynamics simulations of a symmetric NACA 0012 wing at low Reynolds number (Re=60,000) and zero angle of attack. Heated wingtip extents of 10%, 20%, and 30% of the half-span were examined while maintaining a uniform elevated surface temperature on the heated region and ambient conditions elsewhere. Velocity and pressure contour comparisons revealed no discernible differences in the global flow field across configurations. Thus, indicating minimal impact on the external inviscid flow. Decomposition of drag coefficients demonstrated a clear redistribution of pressure and viscous drag contributions between heated and unheated regions as heating extent increased; however, the net drag coefficient remained nearly invariant within numerical uncertainty. These results suggest that spanwise-localized heating alone produces limited aerodynamic effects under symmetric flow conditions and highlight the importance of geometric and loading asymmetry in bioinspired thermal–aerodynamic coupling.