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Flow characteristics of aerial swimmers: flapping wing propulsion of tiny insects flying at extremely low Reynolds numbers

空中游泳者的流动特性：极低雷诺数飞行的微小昆虫的扑翼推进

基本信息

批准号：
277483007
负责人：
Professor Dr. Fritz-Olaf Lehmann
金额：
--
依托单位：
Abteilung Tierphysiologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2021-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/277483007?language=en
关键词：
Flow characteristics aerial swimmers flapping

项目摘要

Investigating the fluid dynamic processes of force production in complex organisms is central for any in-depth understanding of locomotion in flying and swimming animals. Within the past decade, the unusual and potent mechanisms of lift production in insects and birds have attracted numerous researchers in the field of biological fluid dynamics. Most studies on insect aerodynamics considered animal wings as simple, mostly rigid, flat plates, flapping at high Reynolds numbers between approximately 200 and 10,000. Flight of small insects with wingspans of less than a millimetre, by contrast, had been excluded from this analysis because tiny insects have abandoned altogether airfoil action and literally swim in the air. In contrast to conventional insects and birds, moreover, small insects exhibit unusual wings of comb-like planform, where up to 80% of the wing surface is replaced by long hairs. There is a pronounced gap in our understanding of the aerodynamic consequences of bristle wings for creeping flow propulsion including the question of how drag-based propulsion systems may generate vertical lift for body weight support. This proposal is thus concerned with the fluid dynamic phenomenon in smallest insects flying at Reynolds numbers below approximately 10. We aim to quantify flow structures of bristle wing fliers, scoring wing kinematics by high-speed video technique and quantifying flow structures by time-resolved digital particle image velocimetry (TRPIV). Employing robotic wings, we will determine the functional relevance of bristle wing design on both wake structure and force generation, and subsequently compare flow structures at flapping model wings with the data obtained from the flying insect. The results of this work might give us several new insights into animal locomotion, i.e. by estimating boundary layer structure and viscous drag propulsion in a miniaturized biological flight system and by providing aerodynamic key values for flight that may be used to determine power expenditures and flight efficiency in highly viscous environments.

研究复杂生物体中力产生的流体动力学过程对于深入了解飞行和游泳动物的运动至关重要。在过去的十年中，昆虫和鸟类中不寻常的和有效的升力产生机制吸引了生物流体动力学领域的许多研究人员。大多数关于昆虫空气动力学的研究都认为动物的翅膀是简单的，大部分是刚性的平板，在大约200到10，000之间的高雷诺数下拍打。相比之下，翼展小于1毫米的小昆虫的飞行被排除在分析之外，因为小昆虫完全放弃了机翼动作，而是在空气中游泳。此外，与传统昆虫和鸟类相比，小型昆虫表现出不寻常的梳状平面形状的翅膀，其中高达80%的翅膀表面被长毛所取代。在我们对刚毛翼用于爬行流推进的空气动力学后果的理解方面存在明显的差距，包括基于阻力的推进系统如何产生垂直升力以支撑体重的问题。因此，该建议涉及在雷诺数低于约10时飞行的最小昆虫中的流体动力学现象。我们的目标是量化的刚毛翼飞行器的流场结构，得分翼运动学的高速视频技术和量化的流场结构的时间分辨数字粒子图像测速（TRPIV）。采用机器人的翅膀，我们将确定刚毛翼设计的功能相关性的尾流结构和力的产生，并随后比较流结构在扑动模型翅膀从飞行昆虫获得的数据。这项工作的结果可能会给我们几个新的见解动物运动，即通过估计边界层结构和粘性阻力推进在一个小型化的生物飞行系统，并通过提供空气动力学的关键值的飞行，可用于确定功率消耗和高粘性环境中的飞行效率。