Impact of albatross's wing colors on their skin friction drag: thermal analysis and blasius boundary layer solution

摘要

The thermal effects of wing color in flight of albatrosses are investigated with respect to their flight routes, migration time, and geometric and behavioral characteristics. Considering the marine and atmospheric characteristics of their flight routes, a thermal analysis of the albatrosses' wings is performed during their migration. The surrounding fluxes including the ocean flux and the sun irradiation are considered in an energy balance in order to determine the skin temperature of both sides of the wing. Applying the Blasius solution for heated boundary layers, it is shown that the color configuration of these migrating birds, namely black on the top side of the wings and white on the bottom side of the wings ("countershading"), results in a skin drag reduction, if compared to some other configurations, when both day and night are taken into consideration. This drag reduction can be considered as one of the effective factors for long endurance of these migrating birds. This research can provide the evolutionary perspective behind the colorization of these migrating birds.