Collaborative Research: Flying snakes: fluid mechanics of deforming articulated bodies

合作研究：飞蛇：关节体变形的流体力学

• 批准号: 2027532
• 负责人: Pavlos Vlachos
• 金额: $ 16万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2027532&HistoricalAwards=false
• 关键词: Collaborative; Research; Flying; snakes; fluid

There are numerous forms of flight ranging from the natural flapping of insect wings to engineered multi-rotor helicopters. Among the diversity of systems for producing flight forces, the flying snake embodies a highly unexpected and non-intuitive solution for aerial locomotion. With a cylindrical body, the snake has no extendable surfaces to create or control flight forces. Despite these limitations, the Asian arboreal species known as ‘flying’ snakes possess a surprisingly sophisticated ability to glide. These snakes jump from trees, flatten their body, and undulate in the air in a complex three-dimensional pattern to produce aerial locomotion. Most surprisingly, the snakes can actively maneuver in the air, capable of turning in mid-air under their own volition. Understanding how flying snakes achieve such feats is the first step toward duplicating this behavior in engineered devices, which could significantly advance design of robots in complex environments, with important applications to surveillance, search-and-rescue, and disaster monitoring. The aerial interaction physics of flying snakes - the strong coupling between the translational and rotational degrees of freedom of the snake as an articulated body - is largely unknown. This project will test the hypothesis that translational-rotational coupling is achieved through feedback between self-deformations (driven by undulation) and unsteady fluid mechanics. The research will use a combination of animal observations, experimental fluid mechanics, and computational fluid dynamics to reveal the fluid mechanics of deforming articulated bodies, of which the flying snake (genus Chrysopelea) is the prime example. The application of adaptive mesh refinement-based immersed boundary method to study fluid flows produced by gliding snakes will enable more efficient investigations on other complex fluids problems with dynamically moving objects across a wide range of Reynolds numbers. The proposed experimental and computational framework can potentially re-define the form and function of locomotion in fluid media for aerial and underwater robotic systems with enhanced mobility. The project involves a broad participation plan that will benefit a diverse range of groups. The principal investigators will engage under-represented students through programmatic connections to regional HBCUs, for summer undergraduate research as well as recruiting of graduate research assistants, at the three collaborating universities. Flying snakes excite the imagination of both students and the public, and the results of the experiments and computations will be disseminated both professionally and publicly, to media outlets and also directly to the public through social media.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

飞行的形式多种多样，从昆虫翅膀的自然拍动到工程化的多旋翼直升机，在产生飞行力的系统的多样性中，飞蛇体现了一种非常意想不到且非直观的圆柱形空中运动解决方案。尽管蛇的身体没有可伸展的表面来产生或控制飞行力，但被称为“飞蛇”的亚洲树栖物种却拥有令人惊讶的复杂能力，这些蛇可以从树上跳下来，变平。最令人惊讶的是，蛇可以在空中主动机动，能够根据自己的意志在空中转弯，了解飞蛇如何实现这一目标。这项壮举是在工程设备中复制这种行为的第一步，这可以显着推进复杂环境中机器人的设计，在监视、搜索和救援以及灾害监测方面具有重要应用。之间的耦合蛇作为铰接体的平移和旋转自由度在很大程度上是未知的，该项目将测试平移旋转耦合是通过自变形（由波动驱动）和非定常流体力学之间的反馈来实现的假设。将结合动物观察、实验流体力学和计算流体动力学来揭示变形铰接体的流体力学，其中飞蛇（Chrysopelea）就是自适应网格的应用的典型例子。基于细化的浸没边界方法来研究滑行蛇产生的流体流动，将使对各种雷诺数范围内动态移动物体的其他复杂流体问题进行更有效的研究。所提出的实验和计算框架有可能重新定义形式和计算框架。该项目涉及一项广泛的参与计划，该计划将使不同的群体受益，主要研究人员将在夏季通过与地区 HBCU 的计划联系来吸引代表性不足的学生。三所合作大学的本科生研究以及研究生研究助理的招募激发了学生和公众的想象力，实验和计算的结果将在专业和公开场合向媒体和公众传播。通过社交媒体直接向公众公布。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

The aerodynamics of flying snake airfoils in tandem configuration

串联配置的飞蛇翼型的空气动力学

• DOI: 10.1242/jeb.233635
• 发表时间: 2021-07
• 期刊: Journal of Experimental Biology
• 影响因子: 2.8
• 作者: Jafari, Farid;Holden, Daniel;LaFoy, Roderick;Vlachos, Pavlos P.;Socha, John J.
• 通讯作者: Socha, John J.