CAREER: An Integrated Study of Biological Fluid Dynamics in Nature

[55949]机翼动态形态的变化直接影响瞬时气动力，从而影响飞行行为。由于大多数天然飞行动物（如蜻蜓、蜂鸟等）都具有柔性或可变形的翅膀，因此人们普遍认为，翅膀柔性和翅膀变形机制可以为完全刚性的翅膀提供新的气动力产生机制。本研究旨在通过综合计算和实验方法，促进自由飞行动物的生物流体动力学知识。到目前为止，在动物自由飞行研究中，很少有关于扑动过程中三维机翼变形的详细测量和相关气动效益的工作。这主要是由于翅膀尺寸小，翅膀的快速运动，以及飞行昆虫/鸟类的不可预测的运动，这使得对翅膀弯曲的细节进行高速视觉跟踪非常困难。为了使这项研究成为可能，目前正在开发两套由实验测量和计算流模拟/分析组成的技术。有了这样的工具和进步，现在有可能揭示围绕复杂飞行动力学和昆虫飞行背后的基本物理奥秘。智力优势：以往的研究大多局限于单个刚性扑翼的近场涡形成机制。PI目前的研究探索了自由飞行的动物在全场涡结构和相关的空气动力学的可变形的扑翼与身体。通过最先进的浸入式边界计算流体动力学求解器和流场分析工具，探讨了涡结构与气动力相关的基本机制。与生物学家和实验学家合作，这项拟议的研究将对蜂鸟和鹰蛾等双翼飞行动物以及蜻蜓和豆娘等四翼飞行动物的翅膀形态和运动学进行比较研究。更好地了解动物翅膀变形如何影响飞行效率，以及运动翅膀如何影响其周围流体环境，将在动物大小和物种之间发展。本工作旨在最终推动动物飞行空气动力学在低速低雷诺数流动物理和与可变形控制面涡动力学相关的动力产生方面的综合理论的发展。这项工作的方法和发现可以被不同领域的科学家用来以以前不可能的方式研究动物飞行的生物学方面，从而显著推进当前具有优越性能的扑翼微型飞行器的设计。更广泛的影响：这项拟议的研究将通过PI与合作者在生物学、应用数学和工程方面的专业知识之间的互动，加强研究和教育的基础设施，无论是在国内还是在国际上。研究工作与教育和推广计划充分结合，以满足生物工程不断增长的教育需求。新课程和实践高级顶点项目将被开发，以吸引赖特州立大学所有背景的学生，并被其他研究所的合作者利用。本研究计划更积极的目标是建立一个基于网络的生物流体动力学相关活动的互动平台，不仅可供工程研究界使用，也可供生物学研究界使用，以及教师和学生在不同层次上使用。在这项工作中建立的工具有潜力用于研究其他低速低雷诺数流体动力学问题，如游泳、高效风能转换、风的损伤预防、内部生物医学流体动力学应用等等。

1055949DongChanges in the dynamic morphology of the wings directly affect the instantaneous aerodynamic forces and therefore flight behavior. As most natural fliers (e.g. dragonflies, hummingbirds and etc.) are equipped with flexible or deformable wings, it is widely believed that mechanism of wing flexibility and wing deformation can provide new mechanisms of aerodynamic force production over completely rigid wings. This proposed research intends to advance the knowledge of biological fluid dynamics in freely flying animals through an integrated computational and experimental approach. As of today, few works have been done on detailed measurements of 3D wing deformation during flapping and the associated aerodynamic benefits in the study of animal free flight. This is mainly due to the small wing size, fast motion of the wings, and unpredictable motion of flying insects/birds which makes it very hard to perform high-speed visual tracking of the details of wing flexions. To make this study possible, two sets of techniques composed of experimental measurement and computational flow simulation/analysis are currently being developed. Equipped with such tools and advancements, it is now possible to reveal the mysteries surrounding complex flight dynamics and the fundamental physics behind insect flight.Intellectual merit: Most previous studies were limited to near-field vortex formation mechanisms of a single rigid flapping wing. The PI's current research explores freely flying animals on full-field vortex structures and associated aerodynamics of deformable flapping wings together with bodies. The fundamental mechanism of correlation between vortex structures and aerodynamic force is being explored through a state-of-the-art immersed boundary computational fluid dynamics solver and fluid-field analysis tools. Teamed up with biologists and experimentalists, this proposed research will conduct comparative studies on wing morphology and kinematics for two-winged flyers such as hummingbirds and hawk moths, as well as four-winged flyers such as dragonflies and damselflies. A better understanding of how animal wing deformation impacts the efficiency of flight and how moving wings affect their ambient fluid environment will be developed across the animal sizes and species. This work intends to finally advance the development of a comprehensive theory of animal flight aerodynamics in the aspect of low speed low Reynolds number flow physics and dynamic force generation associated with vortex dynamics of deformable control surfaces. Methods and findings from this work could be used by scientists in different areas to study the biological aspects of animal flight in ways previously not possible, and therefore significantly advance the design of current flapping-wing micro air vehicles with superior performance. Broader impacts: This proposed research will enhance the infrastructure for research and education through the interactions between the PI and collaborators' expertise in biology, applied mathematics, and engineering, both nationally and internationally. The research effort fully integrates with an education and outreach program to meet the ever-increasing educational demands of bio-engineering. New courses and hands-on senior capstone projects will be developed to attract students of all backgrounds at Wright State University and be utilized by collaborators from other institutes. A more aggressive goal of this research project is to build a web-based interactive platform for biological fluid dynamics related activities, which is accessible to not only the engineering research community but also to the biological research community, as well as teachers and students at many levels. The tools built in this proposed work have the potential to be used to study other low speed low Reynolds number fluid dynamic problems such as swimming, efficient wind energy conversion, damage prevention from gusts, internal biomedical fluid dynamics applications and more.