The deviation angles during wing flapping motions are generally small for many insects and are known to have insignificant or even detrimental effects on the flight performance. Unlike many other insects, a mosquito hovers with a small sweeping amplitude but relatively large deviation angles. Thus, we investigate the effect of a deviation motion (‘figure-eight’ motion measured by Bomphrey et al. (2017)) on the aerodynamic performance of a mosquito wing in hover by comparing it with that without deviation motion (called in-plane motion). During the stroke, the deviation motion greatly changes the angle of attack and wing moving direction with respect to the stroke plane, but little changes the wing speed. These changes by the deviation motion significantly influence the instantaneous force and power generation. In particular, with the deviation motion, a large drag force is generated at early phase of the downstroke due to the increased angle of attack, and contributes to the vertical force generation. As results, the time-averaged vertical force is increased by the deviation motion, while the time-averaged power required is only slightly increased. Therefore, the mosquito wing generates a larger vertical force more efficiently with the deviation motion, suggesting that a deviation motion may be beneficial for an insect flight with a small sweeping amplitude.

对于许多昆虫来说，翅膀扑动运动期间的偏差角通常很小，并且已知对飞行性能具有微不足道的甚至有害的影响。与许多其他昆虫不同，蚊子以较小的扫掠幅度但相对较大的偏离角悬停。因此，我们通过与没有偏差运动（称为面内运动）进行比较，研究了偏差运动（Bomphrey 等人（2017）测量的“八字形”运动）对悬停时蚊翼空气动力学性能的影响。运动）。在划水过程中，偏差运动极大地改变了迎角和机翼相对于划水平面的运动方向，但对机翼速度的改变很小。这些由偏差运动引起的变化显着影响瞬时力和发电量。特别是，在偏向运动中，由于迎角增大，在下冲程的早期阶段会产生较大的阻力，并有助于垂直力的产生。结果，时间平均垂直力因偏离运动而增加，而所需的时间平均功率仅略有增加。因此，蚊子翅膀通过偏离运动更有效地产生更大的垂直力，这表明偏离运动可能有利于小扫掠幅度的昆虫飞行。