在2月29日的《科學(xué)》（Science）雜志上,，研究人員報道說，蝙蝠用的是與昆蟲相同的空氣動力學(xué)技巧在高空中逗留,。當(dāng)蝙蝠的翼翅向下扇動時,，這一動作產(chǎn)生了一種叫做“前緣渦流”的細(xì)微氣旋,，蝙蝠籍此使其身體向上提拉,。人們已知昆蟲在飛行時會運(yùn)用這種渦流,，但是研究人員不知道這種機(jī)制是否也適用于較大、較重的動物如蝙蝠,，特別是當(dāng)其緩慢飛行或在空中盤旋滑翔的時候,。
Florian Muijres及其瑞典和美國的同僚對小體型的在風(fēng)道中飛行的吸蜜蝙蝠進(jìn)行了研究,。在煙霧機(jī)的幫助下,，研究人員對飛過風(fēng)道的蝙蝠尾流中的煙霧粒子的運(yùn)動進(jìn)行了記錄。結(jié)果顯示,，這些渦流可以提供幫助該類動物在空中停留的高達(dá)40%的提升力,。（來源：EurekAlert!中文版）
生物谷推薦原始出處：
（Science），Vol. 319. no. 5867, pp. 1250 - 1253,，F(xiàn). T. Muijres,，A. Hedenstr
Leading-Edge Vortex Improves Lift in Slow-Flying Bats
F. T. Muijres, L. C. Johansson, R. Barfield, M. Wolf, G. R. Spedding, A. Hedenstr
Staying aloft when hovering and flying slowly is demanding. According to quasi–steady-state aerodynamic theory, slow-flying vertebrates should not be able to generate enough lift to remain aloft. Therefore, unsteady aerodynamic mechanisms to enhance lift production have been proposed. Using digital particle image velocimetry, we showed that a small nectar-feeding bat is able to increase lift by as much as 40% using attached leading-edge vortices (LEVs) during slow forward flight, resulting in a maximum lift coefficient of 4.8. The airflow passing over the LEV reattaches behind the LEV smoothly to the wing, despite the exceptionally large local angles of attack and wing camber. Our results show that the use of unsteady aerodynamic mechanisms in flapping flight is not limited to insects but is also used by larger and heavier animals.
