Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2010 May 7;104(18):184504. doi: 10.1103/PhysRevLett.104.184504. Epub 2010 May 6.
The influence of flexibility on the flight of autorotating winged seedpods is examined through an experimental investigation of tumbling rectangular paper strips freely falling in air. Our results suggest the existence of a critical length above which the wing bends. We develop a theoretical model that demonstrates that this buckling is prompted by inertial forces associated with the tumbling motion, and yields a buckling criterion consistent with that observed. We further develop a reduced model for the flight dynamics of flexible tumbling wings that illustrates the effect of aeroelastic coupling on flight characteristics and rationalizes experimentally observed variations in the wing's falling speed and range.
通过对自由下落的矩形纸在空气中翻滚的实验研究，考察了柔韧性对旋转翼果飞行的影响。我们的研究结果表明，当翼长超过一个临界值时，翼会发生弯曲。我们提出了一个理论模型，证明了这种弯曲是由翻滚运动引起的惯性力引起的，并得到了与观察到的结果一致的屈曲准则。我们进一步为柔性翻滚翼的飞行动力学开发了一个简化模型，说明了空气弹性耦合对飞行特性的影响，并对实验中观察到的翼下降速度和范围的变化进行了合理化解释。
