Three-dimensional effects on sliding and waving wings
Three-dimensional effects on sliding and waving wings
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滑动和挥动翅膀的三维效果
DOI：
10.2514/1.c031184
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发表时间：
2011
影响因子：
2.2
通讯作者：
H. Babinsky
中科院分区：
文献类型：
--
作者：
Anya R. Jones;C. P. Ford;H. Babinsky
与大型昆虫一样，微型飞行器在低雷诺数 O(1; 000 - 10; 000) 下运行，其特点是分离流和强涡流。前缘涡已被确定为昆虫翅膀高升力的重要来源，但形成稳定附着的前缘涡所需的条件尚不清楚。挥动的翅膀旨在通过保留不稳定的启动和停止运动以及翅膀几何形状（通过有限跨度翅膀）和运动学（通过翅膀旋转）的三维性来模拟昆虫翅膀行程的平移阶段。目前的研究研究了展向速度梯度对机翼前缘涡流发展的影响，以及通过将机翼展弦比从 4 减小到 2 来增加三维度的影响。染料流可视化和粒子图像测速表明，滑动或波动机翼上形成的前缘涡流具有非常高的纵横比。滑动机翼和波动机翼上的流动结构基本上都是二维的，并且前缘涡流和尖端涡流之间的相互作用最小。在摆动翼上观察到显着的翼展方向流动，但在滑动翼上没有观察到。尽管展弦比为 2 的挥动机翼的三维度有所增加，但没有证据表明存在附着的前缘涡，并且流动结构与较高展弦比的机翼和滑动机翼上的流动结构非常相似。 © 版权所有 2010。
Like large insects, micro air vehicles operate at low Reynolds numbers O(1; 000 - 10; 000) in a regime characterized by separated flow and strong vortices. The leading-edge vortex has been identified as a significant source of high lift on insect wings, but the conditions required for the formation of a stably attached leading-edge vortex are not yet known. The waving wing is designed to model the translational phase of an insect wing stroke by preserving the unsteady starting and stopping motion as well as three-dimensionality in both wing geometry (via a finite-span wing) and kinematics (via wing rotation). The current study examines the effect of the spanwise velocity gradient on the development of the leading-edge vortex along the wing as well as the effects of increasing threedimensionalityby decreasing wing aspect ratio from four to two. Dye flow visualization and particle image velocimetry reveal that the leading-edge vortices that form on a sliding or waving wing have a very high aspect ratio. The structure of the flow is largely two-dimensional on both sliding and waving wings and there is minimal interaction between the leading-edge vortices and the tip vortex. Significant spanwise flow was observed on the waving wing but not on the sliding wing. Despite the increased three-dimensionality on the aspect ratio 2 waving wing, there is no evidence of an attached leading-edge vortex and the structure of the flow is very similar to that on the higher-aspect-ratio wing and sliding wing. © Copyright 2010.