扑翼尾迹中细丝的柔性对气动效能的影响

柔性对生物的运动起着至关重要的作用，例如鸟类的飞行和鱼类的游动.对柔性的研究有利于深刻地认识一些动物的运动机制和制造高效推进的仿生机器.文章在侧向自由弹性细丝的模型基础上，对不同柔性细丝的气动效能进行了研究.数值模拟结果表明，在Kárman涡街中，细丝的阻力系数随着其柔性减小而减小，细丝尾端的振幅随着其柔性减小而增大.结果还表明，在一定范围的Reynolds数下，减小细丝柔性，细丝由在涡核之间穿梭摆动运动模式变成在涡街外侧摆动运动模式，其尾涡的对称性也发生了明显的变化. 

Hydrodynamic Performance Influenced by the Flexible Effect of a Semi-Free Filament in the Wake of a Flapping Foil

Flexibility plays an important role in the movement of organisms, such as the flight of birds and the movement of fish. The study of flexibility is conducive to a profound understanding of some animal motion mechanisms and the production of highly efficient bionic machines. Based on the model of lateral free elastic filament, the aerodynamic efficiency of different flexible filaments was studied in this paper. The numerical results show that the drag coefficient of the filament decreases with the decrease of the flexibility, and the amplitude of the tail end of the filament increases with the decrease of the flexibility in Kárman vortex street. The results also show that in a certain range of Reynolds number, the filament swings from the swinging motion mode between the vortex cores to the swinging motion mode outside the vortex street with the decrease of the flexibility. The symmetry of the wake also changes significantly.