CAREER: Numerical Investigations of Biological and Bio-inspired Locomotion

职业：生物和仿生运动的数值研究

• 批准号: 0645228
• 负责人: Jeff Eldredge
• 金额: $ 41.9万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-15 至 2013-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0645228&HistoricalAwards=false
• 关键词: CAREER; Numerical; Investigations; Biological; Bio

AbstractCBET-0645228J. Eldredge, UCLAThe proposed program addresses a need for a high-fidelity, computationally efficient tool for simulating flows produced by bodies with moving, deforming surfaces. This tool will be applicable to a wide range of fluid dynamical problems of biological and technological interest, but focus in this program period will be devoted to studying the role of flexibility in biomorphic locomotion in fluids. The proposed research program consists of two parallel components: (1) Development of a simulation tool for three-dimensional unsteady flow coupled with flexible surfaces, and (2) Numerical investigation of active and passive flexibility in a series of biologically-motivated benchmark problems. The research program will address several open questions of locomotion, and the educational component has a paradigm that is easily accessible to students at many levels.Intellectual merit: The grace and agility with which many organisms self-propel and maneuver in fluids is hardly matched by our own attempts of mimicry. We still lack sufficient understanding of the fundamental physics of most forms of biological locomotion to construct vehicles with similar functionality, despite thousands of years of observation. Investigation of these problems is most effective with a multidisciplinary tandem of experimental, computational and theoretical analysis, and recent interest has led to new and exciting advances with each of these tools. Experiments reveal that highly unsteady vortical flow structures and surface flexibility play critical roles in generating the requisite thrust, lift and maneuvering forces in fish and insects. Numerical simulations serve a powerful and necessary role due to the obvious difficulties in obtaining detailed flow measurements from freely-moving organisms. Conventional flow solvers are not naturally suited to the large surface deformations of biological locomotion. In order to circumvent these difficulties and to exploit the important role of vorticity, the simulations in this program will rely on the viscous vortex particle method, with which the PI has extensive experience. In lieu of a fixed grid, this method uses computational particles that automatically adapt to the evolving flow; because particles are only needed where vorticity is present, the method naturally focuses computational resources on a spatially compact region. The tool will be used to address several open questions regarding biological locomotion, with particular attention devoted to the roles of active and passive flexibility in the basic mechanics. A key development will be the construction and investigation of three canonical "flexible-body locomotion" problems. These problems will each be solved through a hierarchical series of sub-problems that give progressively more insight. The results of these studies can be used for later work in trajectory planning and reduced-order modeling, with the ultimate goal of devising control strategies. Broader impacts: The tools and results from this research program will be relevant to other important problems in bio-inspired aquatic and micro air vehicle design and internal biological flows. Furthermore, the results will be distilled and integrated into an educational program that consists of three principal components: development of an undergraduate course on the fluid dynamics of biological systems; visits to local K-12 schools through the UCLA Center for Excellence in Engineering and Diversity; and development and mentoring of undergraduate research projects. Each of these components will use the paradigm of natural locomotion to motivate fundamental concepts in fluid dynamics, and engineering in general. The visits to local schools in the Los Angeles and Inglewood Unified School Districts will focus on drawing students from disadvantaged and traditionally underrepresented groups into science and engineering. The PI and a small group of undergraduate assistants will engage the students by asking questions such as "Why doesn't an airplane fly like an insect?", and then lead interactive discussions and demonstrations that encourage broad participation.

摘要CBET-0645228 J。埃尔德雷奇，加州大学洛杉矶分校提出的计划解决了需要一个高保真，计算效率高的工具，模拟流动产生的机构与移动，变形表面。该工具将适用于广泛的生物和技术兴趣的流体动力学问题，但在此计划期间的重点将致力于研究在流体中的生物形态运动的灵活性的作用。建议的研究计划包括两个并行部分：（1）开发一个三维非定常流耦合柔性表面的模拟工具，和（2）在一系列生物学激励的基准问题的主动和被动的灵活性的数值研究。该研究计划将解决几个悬而未决的问题的运动，和教育部分有一个范例，是很容易接近的学生在许多层次。智力优点：优雅和敏捷与许多生物体自我推进和机动的流体是很难匹配我们自己的模仿尝试。尽管经过数千年的观察，我们仍然缺乏对大多数生物运动形式的基本物理学的足够理解，无法建造具有类似功能的车辆。这些问题的调查是最有效的实验，计算和理论分析的多学科串联，最近的兴趣导致了新的和令人兴奋的进展，这些工具。实验表明，高度不稳定的涡流结构和表面的灵活性在产生必要的推力，升力和操纵力的鱼类和昆虫中起着关键作用。数值模拟服务于一个强大的和必要的作用，由于在获得详细的流量测量从自由移动的生物体的明显困难。 传统的流动求解器不自然地适合于生物运动的大表面变形。为了克服这些困难并充分利用涡量的重要作用，本程序中的模拟将依赖于PI具有丰富经验的粘性涡粒子法。代替固定网格，该方法使用自动适应不断变化的流动的计算粒子;因为粒子只需要存在涡量的地方，该方法自然地将计算资源集中在空间紧凑的区域。该工具将被用来解决几个悬而未决的问题，生物运动，特别关注的作用，主动和被动的灵活性的基本力学。一个关键的发展将是三个典型的“柔性身体运动”问题的构建和研究。这些问题都将通过一系列分层次的子问题来解决，这些子问题会逐步提供更多的洞察力。这些研究的结果可以用于以后的工作中的轨迹规划和降阶建模，设计控制策略的最终目标。更广泛的影响：该研究计划的工具和结果将与生物启发的水生和微型飞行器设计和内部生物流中的其他重要问题相关。此外，研究结果将被提炼并整合到一个教育计划中，该计划包括三个主要组成部分：生物系统流体动力学本科课程的开发;通过加州大学洛杉矶分校卓越工程和多样性中心访问当地K-12学校;以及本科研究项目的开发和指导。这些组件中的每一个都将使用自然运动的范例来激发流体动力学和工程学中的基本概念。对洛杉矶和英格伍德联合学区当地学校的访问将集中在吸引来自弱势群体和传统上代表性不足的群体的学生进入科学和工程领域。PI和一小群本科生助理将通过问诸如“为什么飞机不能像昆虫一样飞行？”“，然后引导互动讨论和示范，鼓励广泛参与。