Collaborative Research: Scaling of ciliary flows at intermediate Reynolds number

合作研究：中间雷诺数纤毛流的缩放

• 批准号: 2120505
• 负责人: Chengyu Li
• 金额: $ 18.39万
• 依托单位: Villanova University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-05-15 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2120505&HistoricalAwards=false
• 关键词: Collaborative; Research; Scaling; ciliary; flows

Cilia are flexible hair-like appendages commonly used to create fluid motion in biological systems, facilitating swimming, feeding, reproduction, and other functional behaviors. Typical cilia are tens of microns long, but ctenophores (comb jellies) use cilia at much larger scales—around a millimeter in length. At small scales, ciliary flow is highly constrained by fluid viscosity. However, at larger scales, inertia becomes more important, leading to quantitative and qualitative differences in the velocities and forces produced by the cilia. These differences will be explored with a combination of laboratory experiments and computational simulations, using ctenophores as a model system for large-scale cilia. A better understanding of the fluid dynamics of cilia across scales will provide new tools to ask and answer questions related to biology, ecology, and the fundamental physics of how flexible structures create flow across scales. This knowledge may lead to new developments in engineering, including bioinspired devices, sensors, and robots. The project will also include the development of several educational components, including a new module on the viscous-inertial transition for high school physics students and outreach activities for young women interested in engineering.The overall goal of the project is to understand the physical principles that govern ciliary flows from low to intermediate Reynolds numbers. This study will explicitly examine the effects of substrate geometry and deformability on ciliary flows. A combined experimental-numerical approach will be used to investigate hydrodynamic interactions of multiple flexible propulsors at low-to-intermediate Reynolds numbers and develop useful scaling laws. The experimental approach will employ both planar and volumetric particle image velocimetry to visualize the flows generated by living ctenophores across a range of animal and propulsor sizes. The material properties of the ciliary substrate (mesoglea) will also be characterized during the investigation. These results will guide the development of a scalable computational fluid dynamics model, which will be used to investigate the larger parameter space of ciliary flow generation across scales. The project will focus on the effects of three key variables: (i) propulsor kinematics, including the degree of bending and spatiotemporal asymmetry; (ii) substrate geometry, from flat to curved; and (iii) substrate deformability, from rigid to highly deformable. This integrated approach will enable an in-depth investigation of how flexible structures generate flow across the viscous-inertial transition, and the development of broadly applicable scaling principles to guide future technology development.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.

纤毛是一种柔软的毛发状附属物，通常用于在生物系统中产生流体运动，促进游泳，进食，繁殖和其他功能行为。典型的纤毛有几十微米长，但栉水母（梳状水母）使用的纤毛更大，大约有一毫米长。在小尺度下，睫状流受到流体粘度的高度限制。然而，在更大的尺度上，惯性变得更加重要，导致纤毛产生的速度和力的定量和定性差异。这些差异将探索实验室实验和计算模拟相结合，使用栉水母作为大规模纤毛的模型系统。更好地了解纤毛跨尺度的流体动力学将提供新的工具来询问和回答与生物学，生态学和柔性结构如何跨尺度产生流动的基础物理学相关的问题。这些知识可能会导致工程学的新发展，包括生物启发设备，传感器和机器人。该项目还将包括开发几个教育部分，包括为高中物理学生开发一个关于粘性-惯性过渡的新模块，并为对工程感兴趣的年轻妇女开展外联活动，该项目的总体目标是了解从低雷诺数到中等雷诺数控制纤毛流动的物理原理。这项研究将明确检查基板的几何形状和变形性对纤毛流动的影响。将采用实验-数值相结合的方法来研究多个柔性推进器在低到中等雷诺数下的水动力相互作用，并开发有用的标度律。实验方法将采用平面和体积粒子图像测速可视化的流动所产生的活栉水母在一系列的动物和推进器的大小。纤毛基质（中胶层）的材料特性也将在研究过程中进行表征。这些结果将指导一个可扩展的计算流体动力学模型，这将被用来调查跨尺度的睫状流生成的更大的参数空间的发展。该项目将侧重于三个关键变量的影响：（一）推进器运动学，包括弯曲程度和时空不对称性;（二）基板几何形状，从平面到弯曲;和（三）基板变形性，从刚性到高度变形。这种综合方法将使人们能够深入研究柔性结构如何在粘性-惯性过渡区产生流动，并开发广泛适用的缩放原则，以指导未来的技术发展。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Hydrodynamics of Metachronal Motion: Effects of Spatial Asymmetry on the Flow Interaction Between Adjacent Appendages

异时运动的流体动力学：空间不对称性对相邻附属物之间流动相互作用的影响

• DOI: 10.1115/fedsm2022-86967
• 发表时间: 2022
• 期刊: ASME 2022 Fluids Engineering Division Summer Meeting
• 作者: Lou, Zhipeng;Herrera-Amaya, Adrian;Byron, Margaret L.;Li, Chengyu
• 通讯作者: Li, Chengyu

Hydrodynamics of Metachronal Rowing at Intermediate Reynolds Numbers

中雷诺数异时划船的流体动力学

• DOI: 10.1115/imece2023-112572
• 发表时间: 2023
• 期刊: ASME 2023 International Mechanical Engineering Congress and Exposition
• 作者: Lei, Menglong;Lou, Zhipeng;Wang, Junshi;Dong, Haibo;Li, Chengyu
• 通讯作者: Li, Chengyu

A new propulsion enhancement mechanism in metachronal rowing at intermediate Reynolds numbers

中间雷诺数异时划船的新推进增强机制

• DOI: 10.1017/jfm.2023.739
• 发表时间: 2023
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Lionetti, Seth;Lou, Zhipeng;Herrera-Amaya, Adrian;Byron, Margaret L.;Li, Chengyu
• 通讯作者: Li, Chengyu