Simulations illustrate swirling air currents around birds’ wings
Hummingbirds are extreme athletes, deftly hovering and darting between flowers. Now a combination of high-speed filming and computer simulations reveals how the birds’ wings manipulate the surrounding air to aid in flight. The images seen here come from a video of simulated flight that won an American Physical Society Gallery of Fluid Motion award in November.
Above, small pockets of air swirl in tornado-like vortices as a hummingbird turns to its right. Researchers have known that the bird’s wings induce lift by generating what are called leading-edge vortices (represented as thick blue layers around the wing edges). But the air movement is even more complex, the simulations reveal. The sequence of images below, which display only the largest vortices, shows how a bird in flight spawns an array of helpful swirls near different parts of the