Unsteady Aerodynamics of Flapping Wings in Gusty Environments: Gust-mitigation Performance, Flow Physics, and Optimization

微型飞行器（MAV）在广泛的民用和军事行动中发挥着越来越重要的作用。然而，它仍然是具有挑战性的，他们在自然或人为建造的环境中，他们经常遇到各种形式的不稳定的环境流或阵风飞行。昆虫和鸟类等飞行动物由于其扑翼固有的空气动力学能力，可以更成功地减弱不稳定环境流的不利影响。因此，本计画旨在建立扑翼与非定常流结构相互作用之流体动力学基础科学。该项目将量化扑翼与各种阵风相互作用的流型和力产生，以了解扑翼克服环境气流扰动的最佳行为。这项研究的结果将提供科学知识的基础，而不仅仅是直觉，以开发更好的MAV，可以快速从大气阵风中恢复。由于实验流体动力学和机器人技术的跨学科和协作努力，该奖项还将使本科生接触研究生水平的研究，从而激励他们攻读STEM专业的高级学位或职业。此外，通过K-12教育和外联活动，该项目将提高公众意识和代表性不足的群体参与科学和工程。该项目的目标是研究扑翼与非定常环境流结构相互作用的性能和流动物理。这将通过以下方式实现：1）将复杂的机翼-阵风相互作用问题解析为四种典型类型的阵风结构与四种运动学配置中的扑翼之间的相互作用;以及2）将实验和理论流体动力学中的工具与强化学习方法结合起来。这项研究将首先使用参数的实验研究，提供一个全面的量化阵风减缓性能的扑翼。然后，它将发展有关的流动物理学的基本理解机翼产生的和周围的流动结构之间的相互作用，在涡脱落模式，涡量运输动力学，和气动力的生产。将研究前缘涡（LEV）的三维性和稳定性对阵风减缓和涡量动力学的影响。最后，该研究将使用强化学习方法和硬件在环优化来优化仿生机器人扑翼的阵风缓解性能。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。

Micro Air Vehicles (MAVs) have a growing role in a broad range of civil and military operations. However, it is still challenging for them to fly robustly in natural or human-constructed environments, where they routinely encounter various forms of unsteady ambient flow or wind gusts. Flying animals such as insects and birds can attenuate the adverse effects of unsteady ambient flow with much greater success, due to the inherent aerodynamic capability of their flapping wings. Therefore, this project aims to establish the fundamental science underlying the fluid dynamics of flapping wings interacting with unsteady flow structures. This project will quantify the flow patterns and force production of flapping wings in interaction with various wind gusts to understand the best behavior for flapping wings to overcome the ambient flow disturbances. The results of this research will provide a foundation of scientific knowledge rather than mere intuition to develop better MAVs that can quickly recover from atmospheric gusts. Because of the cross-disciplinary and collaborative efforts in experimental fluid dynamics and robotics, this award will also expose undergraduate students to graduate-level research, thereby inspiring them to pursue advanced degrees or careers in STEM majors. Moreover, through K-12 education and outreach activities, this project will increase the public awareness and underrepresented groups engagements in science and engineering. The goal of this project is to investigate the performance and the flow physics of flapping wings in interactions with unsteady ambient flow structures. This will be enabled by 1) parsing the complex wing-gust interaction problem into the interactions between four canonical types of gust structures and flapping wings in four kinematic configurations; and 2) coalescing tools in experimental and theoretical fluid dynamics with reinforcement learning methods. This research will first use parametric experimental studies to provide a comprehensive quantification of the gust-mitigation performance of flapping wings. Then, it will develop fundamental understandings of the flow physics pertinent to the interactions between wing-generated and ambient flow structures, in terms of vortex shedding pattern, vorticity transport dynamics, and aerodynamic force production. Effects of three-dimensionality and stability of the leading edge vortex (LEV) on gust-mitigation and vorticity dynamics will be studied. Finally, this research will use reinforcement learning methods and hardware-in-the-loop optimization to optimize the gust-mitigation performance of bioinspired robotic flapping wings.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.