Collaborative Research: New models and numerical methods for flexible wings, fins, and membranes

该项目的目标是创建分析和计算工具，再加上实验，以研究生物推进流体中的中间尺度。这些问题通常涉及柔性附件在惯性和粘度都很重要的流体中的运动。与这些问题相关的基本计算挑战是准确和有效地模拟周围流体中的移动柔性结构。一个目标是将Stokes流的数值方法扩展到1到10的雷诺数。然后，这些方法将被应用于涉及通过刚毛机翼的流动的空气动力学问题。另一个目的是将粘性效应纳入涡面方法，以便更准确地模拟更大范围尺度的流动。然后，这些工具将被用来了解积极控制鱼鳍射线和其他流体与生物体相互作用的重要性。最后，这项工作将允许推进机制和数值方法在很宽的范围内的Reynoldsnumbers.The数值方法和模型的比较，在这个研究项目中开发的可以应用到许多不同的生物流体-结构相互作用的问题。除了这些具体的建议，还有一些例子，包括心脏泵血，肺中的空气流动，柔性材料（如树叶和固着生物）的阻力减少，以及种子在空气中的传播和幼虫在水中的传播。这项工作的更广泛的影响，包括推进力学，可用于微型空气和水的车辆的设计的更好的理解;计算工具的发展，这是有用的研究优化问题在生物学;丰富的例子，非线性动力学的物理;研究指导本科生在实验和建模工作和研究生在计算和建模研究。外展部分将帮助更多学生通过独立的研究项目实现研究和批判性思维的自主性。该项目还解决了美国国家科学院提出的关于理论在推进21世纪世纪生物学中的作用的七个问题之一："生命的工程原理是什么？''

The goals of this project are to create analytical and computational tools, coupled with experiments, to investigate biological propulsion in fluids at intermediate scales. These problems typically involve the movement of a flexible appendage in a fluid where both inertia and viscosity are important. The fundamental computational challenge associated with these problems is the accurate and efficient simulation of the moving, flexible structure in the surrounding fluid. One aim is to extend numerical methods for Stokes flow to Reynolds numbers on the order of 1 to 10. These methods will then be applied to aerodynamics problems involving flow through bristled wings. Another aim is to incorporate viscous effects into vortex sheet methods, in order to more accurately simulate flows over a wider range of scales. These tools will then be used to understand the importance of active control of fish fin rays and other instances of fluid interactions with organisms. Finally, this work will allow for comparisons of propulsion mechanisms and numerical methods across a wide range of Reynolds numbers.The numerical methods and models developed in this research project can be applied to numerous and diverse biological fluid-structure interactions problems. Some examples beyond those specific to the proposal include the pumping of blood by the heart, the flow of air in the lungs, drag reduction in flexible materials such as leaves and sessile organisms, and the dispersal of seeds in air and larvae in water. The broader impacts of this work include the improved understanding of propulsion mechanics that can be used for the design of micro air and water vehicles; the development of computational tools which are useful to study optimization questions in biology; rich examples of nonlinear dynamics for physics; research mentoring to undergraduates in experimental and modeling work and graduate students in computational and modeling research. The outreach component will help more students achieve autonomy in research and critical thinking through independent research projects. This project also addresses one of the seven questions posed by the National Academy of Sciences on the role of theory in advancing 21st century biology: ``what are the engineering principles of life?''