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.

纤毛是通常用于在生物系统中产生流体运动的柔性柔性附件，支持游泳，喂养，繁殖和其他功能行为。典型的纤毛长度是数十微米，但是c曲子（梳子）在更大的尺度上使用纤毛，长度为毫米。在小尺度上，睫状流受到流体粘度的高度限制。但是，在较大的尺度上，惯性变得越来越重要，从而导致纤毛产生的速度和力的定量和定性差异。将使用Cenophores作为大规模纤毛的模型系统来探索这些差异。更好地了解纤毛跨尺度的流体动力学将提供新的工具，以询问和回答与生物学，生态学以及灵活结构如何跨尺度产生流程的基本物理学有关的问题。这些知识可能会导致工程方面的新发展，包括生物启发的设备，传感器和机器人。该项目还将包括开发几个教育组成部分，包括针对高中物理学生的粘性惯性过渡的新模块以及针对对工程感兴趣的年轻女性的外展活动。该项目的总体目标是了解从低到中间的纤毛流到中间的纤毛原理。这项研究将明确检查底物几何形状和变形性对睫状流的影响。合并的实验数方法将用于研究低到中级雷诺数在低到中间的弹性推进器数量的流体动力相互作用并制定有用的缩放定律。实验方法将同时采用平面和体积粒子图像速度计，以可视化通过跨各种动物和推进器大小的活体产生的流量。睫状底物（Mesobrea）的材料特性也将在投资期间进行表征。这些结果将指导一个可扩展的计算流体动力学模型的开发，该模型将用于研究跨音阶的睫状流产生的较大参数空间。该项目将侧重于三个关键变量的影响：（i）推进器运动学，包括弯曲程度和时空不对称程度； （ii）从平坦到弯曲的底物几何形状； （iii）底物可变形性，从刚性到高度变形。这种综合方法将对灵活的结构在整个粘性惯性过渡中产生流动以及广泛适用的缩放原则的发展，以指导未来的技术发展。该奖项反映了NSF的法定任务，并被认为是通过评估基金会的智力和更广泛的影响，该奖项被视为珍贵的支持，以指导未来的技术发展。

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