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On the role of initial velocities in pair dispersion in a microfluidic chaotic flow
Chaotic flows drive mixing and efficient transport in fluids, as well as the associated beautiful complex patterns familiar to us from our every day life experience. Generating such flows at small scales where viscosity takes over is highly challenging from both the theoretical and engineering persp...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5589773/ https://www.ncbi.nlm.nih.gov/pubmed/28883492 http://dx.doi.org/10.1038/s41467-017-00389-8 |
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author | Afik, Eldad Steinberg, Victor |
author_facet | Afik, Eldad Steinberg, Victor |
author_sort | Afik, Eldad |
collection | PubMed |
description | Chaotic flows drive mixing and efficient transport in fluids, as well as the associated beautiful complex patterns familiar to us from our every day life experience. Generating such flows at small scales where viscosity takes over is highly challenging from both the theoretical and engineering perspectives. This can be overcome by introducing a minuscule amount of long flexible polymers, resulting in a chaotic flow dubbed ‘elastic turbulence’. At the basis of the theoretical frameworks for its study lie the assumptions of a spatially smooth and random-in-time velocity field. Previous measurements of elastic turbulence have been limited to two-dimensions. Using a novel three-dimensional particle tracking method, we conduct a microfluidic experiment, allowing us to explore elastic turbulence from the perspective of particles moving with the flow. Our findings show that the smoothness assumption breaks already at scales smaller than a tenth of the system size. Moreover, we provide conclusive experimental evidence that ‘ballistic’ separation prevails in the dynamics of pairs of tracers over long times and distances, exhibiting a memory of the initial separation velocities. The ballistic dispersion is universal, yet it has been overlooked so far in the context of small scales chaotic flows. |
format | Online Article Text |
id | pubmed-5589773 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-55897732017-09-11 On the role of initial velocities in pair dispersion in a microfluidic chaotic flow Afik, Eldad Steinberg, Victor Nat Commun Article Chaotic flows drive mixing and efficient transport in fluids, as well as the associated beautiful complex patterns familiar to us from our every day life experience. Generating such flows at small scales where viscosity takes over is highly challenging from both the theoretical and engineering perspectives. This can be overcome by introducing a minuscule amount of long flexible polymers, resulting in a chaotic flow dubbed ‘elastic turbulence’. At the basis of the theoretical frameworks for its study lie the assumptions of a spatially smooth and random-in-time velocity field. Previous measurements of elastic turbulence have been limited to two-dimensions. Using a novel three-dimensional particle tracking method, we conduct a microfluidic experiment, allowing us to explore elastic turbulence from the perspective of particles moving with the flow. Our findings show that the smoothness assumption breaks already at scales smaller than a tenth of the system size. Moreover, we provide conclusive experimental evidence that ‘ballistic’ separation prevails in the dynamics of pairs of tracers over long times and distances, exhibiting a memory of the initial separation velocities. The ballistic dispersion is universal, yet it has been overlooked so far in the context of small scales chaotic flows. Nature Publishing Group UK 2017-09-07 /pmc/articles/PMC5589773/ /pubmed/28883492 http://dx.doi.org/10.1038/s41467-017-00389-8 Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Afik, Eldad Steinberg, Victor On the role of initial velocities in pair dispersion in a microfluidic chaotic flow |
title | On the role of initial velocities in pair dispersion in a microfluidic chaotic flow |
title_full | On the role of initial velocities in pair dispersion in a microfluidic chaotic flow |
title_fullStr | On the role of initial velocities in pair dispersion in a microfluidic chaotic flow |
title_full_unstemmed | On the role of initial velocities in pair dispersion in a microfluidic chaotic flow |
title_short | On the role of initial velocities in pair dispersion in a microfluidic chaotic flow |
title_sort | on the role of initial velocities in pair dispersion in a microfluidic chaotic flow |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5589773/ https://www.ncbi.nlm.nih.gov/pubmed/28883492 http://dx.doi.org/10.1038/s41467-017-00389-8 |
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