Lilong Chuyi, Yu Yongliang
Laboratory for Biomechanics of Animal Locomotion, University of Chinese Academy of Sciences, Beijing 100049, China.
Biomimetics (Basel). 2024 Feb 29;9(3):148. doi: 10.3390/biomimetics9030148.
Flapping-wing micro air vehicles (FWMAVs) have gained much attention from researchers due to their exceptional performance at low Reynolds numbers. However, the limited understanding of active aerodynamic modulation in flying creatures has hindered their maneuverability from reaching that of their biological counterparts. In this article, experimental investigations were conducted to examine the effect of the bilateral amplitude asymmetry of flexible flapping wings. A reduced bionic model featuring bat-like wings is built, and a dimensionless number ΔΦ* is introduced to scale the degree of bilateral amplitude asymmetry in flapping motion. The experimental results suggest that the bilateral amplitude-asymmetric flapping motion primarily induces maneuvering control forces of coupling roll moment and yaw moment. Also, roll moment and yaw moment have a good linear relationship. To achieve more efficient maneuvers based on this asymmetric motion, it is advisable to maintain ΔΦ* within the range of 0 to 0.4. The magnitude of passive pitching deformation during the downstroke is significantly greater than that during the upstroke. The phase of the peak of the passive pitching angle advances with the increase in flapping amplitude, while the valleys lag. And the proportion of pronation and supination in passive pitching motion cannot be adjusted by changing the flapping amplitude. These findings have important practical relevance for regulating turning maneuvers based on amplitude asymmetry and help to understand the active aerodynamic modulation mechanism through asymmetric wing kinematics.
扑翼微型飞行器（FWMAVs）因其在低雷诺数下的卓越性能而备受研究人员关注。然而，对飞行生物主动气动调制的有限理解阻碍了它们的机动性达到与其生物同类相当的水平。在本文中，进行了实验研究以考察柔性扑翼双边振幅不对称的影响。构建了一个具有蝙蝠状翅膀的简化仿生模型，并引入无量纲数ΔΦ来衡量扑翼运动中双边振幅不对称的程度。实验结果表明，双边振幅不对称的扑翼运动主要诱导耦合滚转力矩和偏航力矩的操纵控制力。而且，滚转力矩和偏航力矩具有良好的线性关系。为了基于这种不对称运动实现更高效的机动，建议将ΔΦ保持在0至0.4的范围内。下拍过程中被动俯仰变形的幅度明显大于上拍过程。被动俯仰角峰值的相位随扑翼振幅的增加而提前，而谷值则滞后。并且被动俯仰运动中内旋和外旋的比例不能通过改变扑翼振幅来调节。这些发现对于基于振幅不对称调节转弯机动具有重要的实际意义，并有助于通过不对称机翼运动学理解主动气动调制机制。
