CAREER: An Integrated Study of Biological Fluid Dynamics in Nature

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。最自然的飞行物(如蜻蜓、蜂鸟等)由于机翼是柔性或可变形的，人们普遍认为，机翼柔性和机翼变形机制可以为全刚性机翼提供新的气动力产生机制。这项拟议的研究旨在通过计算和实验相结合的方法来促进自由飞行动物中生物流体动力学的知识。到目前为止，在动物自由飞行的研究中，关于扑翼过程中3D机翼变形的详细测量以及相关的空气动力学益处的工作很少。这主要是由于机翼体积小，机翼运动速度快，以及飞行昆虫/鸟类的不可预测运动，使得很难对机翼弯曲的细节进行高速视觉跟踪。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动模拟/分析组成的技术。有了这样的工具和进步，现在就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的奥秘。智力优势：以前的大多数研究都局限于单个刚性扑翼的近场涡流形成机制。PI目前的研究探索了自由飞行的动物的全场涡旋结构以及与身体一起变形的扑翼的相关空气动力学。通过一种最先进的浸没边界计算流体力学解算器和流场分析工具，正在探索涡旋结构和气动力之间的基本机制。这项拟议的研究将与生物学家和实验者合作，对蜂鸟和鹰蛾等双翼飞行动物以及蜻蜓和蜻蜓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，以及翅膀移动如何影响环境流体环境，将在动物大小和物种之间形成更好的理解。这项工作旨在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操纵面涡动力学相关的动态力产生方面的综合理论的发展。这项工作的方法和结果可以被不同领域的科学家用来研究动物飞行的生物学方面，这是以前不可能的，因此大大促进了当前性能优越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、应用数学和工程学方面的国内和国际专业知识之间的互动，加强研究和教育的基础设施。这项研究工作与教育和推广计划完全结合在一起，以满足不断增长的生物工程教育需求。将开发新的课程和实践的高级顶峰项目，以吸引莱特州立大学所有背景的学生，并被其他学院的合作者利用。这一研究项目的一个更积极的目标是为生物流体动力学相关活动建立一个基于网络的互动平台，不仅对工程研究社区，而且对生物研究社区，以及多个层面的教师和学生都是可用的。在这项拟议的工作中建立的工具有可能被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、阵风损害预防、内部生物医学流体动力学应用等。

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.