气候变化领域集成服务门户(CCPortal): Stretching and folding sustain microscale chemical gradients in porous media

CCPortal

DOI	10.1073/pnas.2002858117
	Stretching and folding sustain microscale chemical gradients in porous media
	Heyman J.; Lester D.R.; Turuban R.; Méheust Y.; Le Borgne T.
发表日期	2020
ISSN	0027-8424
起始页码	13359
结束页码	13365
卷号	117 期号:24
英文摘要	Fluid flow in porous media drives the transport, mixing, and reaction of molecules, particles, and microorganisms across a wide spectrum of natural and industrial processes. Current macroscopic models that average pore-scale fluctuations into an effective dispersion coefficient have shown significant limitations in the prediction of many important chemical and biological processes. Yet, it is unclear how three-dimensional flow in porous structures govern the microscale chemical gradients controlling these processes. Here, we obtain high-resolution experimental images of microscale mixing patterns in three-dimensional porous media and uncover an unexpected and general mixing mechanism that strongly enhances concentration gradients at pore-scale. Our experiments reveal that systematic stretching and folding of fluid elements are produced in the pore space by grain contacts, through a mechanism that leads to efficient microscale chaotic mixing. These insights form the basis for a general kinematic model linking chaotic-mixing rates in the fluid phase to the generic structural properties of granular matter. The model successfully predicts the resulting enhancement of pore-scale chemical gradients, which appear to be orders of magnitude larger than predicted by dispersive approaches. These findings offer perspectives for predicting and controlling the vast diversity of reactive transport processes in natural and synthetic porous materials, beyond the current dispersion paradigm. © 2020 National Academy of Sciences. All rights reserved.
英文关键词	Chaotic mixing; Chemical gradients; Porous media; Reactive transport
语种	英语
scopus关键词	article; grain
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160918
作者单位	Heyman, J., Géosciences Rennes, Université de Rennes, CNRS, Unité Mixte de Recherche 6118, Rennes, 35000, France; Lester, D.R., School of Engineering, RMIT University, Melbourne, VIC 3000, Australia; Turuban, R., Géosciences Rennes, Université de Rennes, CNRS, Unité Mixte de Recherche 6118, Rennes, 35000, France; Méheust, Y., Géosciences Rennes, Université de Rennes, CNRS, Unité Mixte de Recherche 6118, Rennes, 35000, France; Le Borgne, T., Géosciences Rennes, Université de Rennes, CNRS, Unité Mixte de Recherche 6118, Rennes, 35000, France
推荐引用方式 GB/T 7714	Heyman J.,Lester D.R.,Turuban R.,et al. Stretching and folding sustain microscale chemical gradients in porous media[J],2020,117(24).
APA	Heyman J.,Lester D.R.,Turuban R.,Méheust Y.,&Le Borgne T..(2020).Stretching and folding sustain microscale chemical gradients in porous media.Proceedings of the National Academy of Sciences of the United States of America,117(24).
MLA	Heyman J.,et al."Stretching and folding sustain microscale chemical gradients in porous media".Proceedings of the National Academy of Sciences of the United States of America 117.24(2020).