The Three-Dimensional Flow Structure and Forces of Flapping-Wing Hovering from Experiments

扑翼悬停的三维流动结构和受力实验

• 批准号: 1336548
• 负责人: Matthew Ringuette
• 金额: $ 28.86万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1336548&HistoricalAwards=false
• 关键词: Three; Dimensional; Flow; Structure; Forces

Ringuette, Matthew 1336548 The research objective of this proposal is to understand the unsteady, 3D flow structure produced by a flapping wing in hover, how it relates to the forces, and the effect of key parameters such as stroke amplitude. In nature, flapping wings have low aspect ratios (ARs), and due to the high angles of attack and low Reynolds numbers flow separation and roll-up into vortices occurs. Intellectual MeritWings in hover are known to generate highly 3D, interconnected vortex loops, which shed each half-stroke and create an overall downward jet-like flow to sustain the body weight. Prior experiments using animals or mechanical models, coupled with flow visualization or 2D digital particle image velocimetry (DPIV), have shed light on the loop structure, but the 3D vortex topology and its relationship to the lift force remain open topics. Computational studies focusing primarily on animal configurations provide greater detail and insight. However, there is a lack of experimental, 3-component 3D DPIV data, and the effects of parameters such as half-stroke amplitude, AR, and motion program on the flow structure are not well understood. A key question is: why do hovering animals flap with amplitudes of 3-5 chord lengths? The approach is to perform experiments using a 2-degree-of-freedom flapping-wing model with simplified wing geometries and motions. The goals are to understand the 3D vortex topology, its variation with half-stroke amplitude, AR, and velocity program, and how it relates to the forces. Of interest are changes in the vortex structure for different cases. Diagnostics include dye visualization, stereoscopic DPIV (SDPIV) for 3-component velocity fields, and force measurements.Broader Impacts:This research will provide valuable insight into the design of highly-maneuverable bio-inspired micro air vehicles (MAVs). They can collect scientific information in complex environments, e.g. urban settings, caves, and disaster sites such as collapsed buildings after an earthquake, where conventional drones cannot operate. Moreover, they could operate efficiently in swarms to track the spread of a toxic gas plume, for example. The results of the proposed research will yield a greater understanding of the unsteady vortical flow and how kinematics and AR affect maximum lift, yielding design strategies for flapping-wing MAVs. The educational and outreach component, which focuses on engaging and mentoring students at many levels through hands-on research in bio-inspired propulsion, will motivate them to pursue higher education and careers in STEM. This addresses the need for a national workforce of exceptional scientists and engineers.

Ringuette，Matthew 1336548本提案的研究目标是了解悬停状态下扑翼产生的非定常三维流结构，它与力的关系以及冲程幅度等关键参数的影响。在自然界中，扑翼具有低的展弦比（AR），并且由于大迎角和低雷诺数，会发生流动分离和卷起成涡流。众所周知，悬停中的智能MeritWings会产生高度3D的、相互连接的涡流环，这些涡流环会在每个半冲程中脱落，并产生整体向下的喷射式气流，以维持身体重量。以前的实验使用动物或机械模型，再加上流动可视化或二维数字粒子图像测速（DPIV），揭示了环路结构，但三维涡流拓扑结构及其与升力的关系仍然是开放的话题。计算研究主要集中在动物的配置提供了更多的细节和见解。然而，有一个缺乏的实验，三分量的三维DPIV数据，和参数的影响，如半冲程振幅，AR，和运动程序上的流动结构没有得到很好的理解。一个关键的问题是：为什么盘旋的动物以3-5弦长的振幅拍打？该方法是使用2度的自由度扑翼模型与简化的机翼几何形状和运动进行实验。目标是了解三维涡流拓扑结构，其随半冲程振幅、AR和速度程序的变化，以及它与力的关系。感兴趣的是不同情况下涡结构的变化。诊断包括染料可视化、三维速度场的立体DPIV（SDPIV）和力的测量。更广泛的影响：这项研究将为高度可扩展的生物启发微型飞行器（MAVs）的设计提供有价值的见解。它们可以在复杂的环境中收集科学信息，例如城市环境，洞穴和灾难现场，如地震后倒塌的建筑物，传统无人机无法操作。此外，它们可以成群有效地工作，例如跟踪有毒气体羽流的扩散。所提出的研究的结果将产生一个更好的了解非定常涡流和运动学和AR如何影响最大升力，产生扑翼微型飞行器的设计策略。教育和推广部分，重点是通过生物启发推进的实践研究，在多个层面上吸引和指导学生，将激励他们追求高等教育和STEM职业。这满足了对国家杰出科学家和工程师队伍的需求。