Department of Ecology and Evolutionary Biology, Post Office Box 208105, Yale University, New Haven, CT 06520, USA.
Science. 2011 Sep 9;333(6048):1430-3. doi: 10.1126/science.1205222.
During courtship flights, males of some hummingbird species produce diverse sounds with tail feathers of varying shapes. We show that these sounds are produced by air flowing past a feather, causing it to aeroelastically flutter and generate flutter-induced sound. Scanning laser doppler vibrometery and high-speed video of individual feathers of different sizes and shapes in a wind tunnel revealed multiple vibratory modes that produce a range of acoustic frequencies and harmonic structures. Neighboring feathers can be aerodynamically coupled and flutter either at the same frequency, resulting in sympathetic vibrations that increase loudness, or at different frequencies, resulting in audible interaction frequencies. Aeroelastic flutter is intrinsic to stiff airfoils such as feathers and thus explains tonal sounds that are common in bird flight.
在求偶飞行中，一些蜂鸟物种的雄性会用不同形状的尾羽发出不同的声音。我们表明，这些声音是由空气流过羽毛引起的，导致羽毛空气弹性地颤动并产生颤动引起的声音。在风洞中对不同大小和形状的单个羽毛进行扫描激光多普勒测振仪和高速录像，揭示了多种振动模式，产生了一系列声学频率和谐波结构。相邻的羽毛可以进行空气动力学耦合并以相同的频率颤动，从而产生共鸣振动，增加音量，或者以不同的频率颤动，从而产生可听见的相互作用频率。空气弹性颤动是羽毛等硬翼片固有的，因此解释了鸟类飞行中常见的音调声音。
