Liu H, Aono H
Graduate School of Engineering, Chiba University, Chiba, Japan.
Bioinspir Biomim. 2009 Mar;4(1):015002. doi: 10.1088/1748-3182/4/1/015002. Epub 2009 Mar 4.
Hovering is a miracle of insects that is observed for all sizes of flying insects. Sizing effect in insect hovering on flapping-wing aerodynamics is of interest to both the micro-air-vehicle (MAV) community and also of importance to comparative morphologists. In this study, we present an integrated computational study of such size effects on insect hovering aerodynamics, which is performed using a biology-inspired dynamic flight simulator that integrates the modelling of realistic wing-body morphology, the modelling of flapping-wing and body kinematics and an in-house Navier-Stokes solver. Results of four typical insect hovering flights including a hawkmoth, a honeybee, a fruit fly and a thrips, over a wide range of Reynolds numbers from O(10(4)) to O(10(1)) are presented, which demonstrate the feasibility of the present integrated computational methods in quantitatively modelling and evaluating the unsteady aerodynamics in insect flapping flight. Our results based on realistically modelling of insect hovering therefore offer an integrated understanding of the near-field vortex dynamics, the far-field wake and downwash structures, and their correlation with the force production in terms of sizing and Reynolds number as well as wing kinematics. Our results not only give an integrated interpretation on the similarity and discrepancy of the near- and far-field vortex structures in insect hovering but also demonstrate that our methods can be an effective tool in the MAVs design.
悬停是昆虫的一项神奇技能，在各种大小的飞行昆虫中都能观察到。昆虫悬停时的尺寸效应对于微型飞行器（MAV）领域来说很有研究价值，对比较形态学家而言也非常重要。在本研究中，我们展示了一项关于此类尺寸效应在昆虫悬停空气动力学方面的综合计算研究，该研究使用了一个受生物学启发的动态飞行模拟器来进行，这个模拟器整合了逼真的机翼 - 机身形态建模、扑翼和机身运动学建模以及一个内部的纳维 - 斯托克斯求解器。我们给出了四种典型昆虫悬停飞行的结果，包括天蛾、蜜蜂、果蝇和蓟马，涵盖了从O(10⁴)到O(10¹)的广泛雷诺数范围，这些结果证明了当前综合计算方法在定量建模和评估昆虫扑翼飞行中的非定常空气动力学方面的可行性。基于对昆虫悬停进行实际建模得到的结果，让我们对近场涡旋动力学、远场尾流和下洗流结构，以及它们在尺寸、雷诺数和机翼运动学方面与力产生的相关性有了综合理解。我们的结果不仅对昆虫悬停中近场和远场涡旋结构的相似性和差异给出了综合解释，还表明我们的方法可以成为微型飞行器设计中的有效工具。
