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Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane

The electro-kinetic instability in a pressure driven shear flow near an ion exchange membrane is considered. The electrochemical system, through which an electrical potential drop is applied, consists in a polarization layer in contact with the membrane and a bulk. The numerical investigation contai...

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Autor principal: Magnico, Pierre
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566642/
https://www.ncbi.nlm.nih.gov/pubmed/31091791
http://dx.doi.org/10.3390/ijms20102393
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author Magnico, Pierre
author_facet Magnico, Pierre
author_sort Magnico, Pierre
collection PubMed
description The electro-kinetic instability in a pressure driven shear flow near an ion exchange membrane is considered. The electrochemical system, through which an electrical potential drop is applied, consists in a polarization layer in contact with the membrane and a bulk. The numerical investigation contained two aspects: analysis of the instability modes and description of the Lagrangian transport of fluid and ions. Regarding the first aspect, the modes were analyzed as a function of the potential drop. The analysis revealed how the spatial distribution of forces controls the dynamics of vortex association and dissociation. In particular, the birth of a counter-clockwise vortex between two clockwise vortices, and the initiation of clusters constituting one or two envelopes wrapping a vortex group, were examined. In regards to the second aspect, the trajectories were computed with the fourth order Runge Kutta scheme for the time integration and with the biquadratric upstream scheme for the spatial and time interpolation of the fluid velocity and the ion flux. The results for the periodic mode showed two kinds of trajectories: the trochoidal motion and the longitudinal one coupled with a periodic transverse motion. For the aperiodic modes, other mechanisms appeared, such as ejection from the mixing layer, trapping by a growing vortex or merging vortices. The analysis of the local velocity field, the vortices’ shape, the spatial distribution of the forces and the ion flux components explained these trajectories.
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spelling pubmed-65666422019-06-17 Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane Magnico, Pierre Int J Mol Sci Article The electro-kinetic instability in a pressure driven shear flow near an ion exchange membrane is considered. The electrochemical system, through which an electrical potential drop is applied, consists in a polarization layer in contact with the membrane and a bulk. The numerical investigation contained two aspects: analysis of the instability modes and description of the Lagrangian transport of fluid and ions. Regarding the first aspect, the modes were analyzed as a function of the potential drop. The analysis revealed how the spatial distribution of forces controls the dynamics of vortex association and dissociation. In particular, the birth of a counter-clockwise vortex between two clockwise vortices, and the initiation of clusters constituting one or two envelopes wrapping a vortex group, were examined. In regards to the second aspect, the trajectories were computed with the fourth order Runge Kutta scheme for the time integration and with the biquadratric upstream scheme for the spatial and time interpolation of the fluid velocity and the ion flux. The results for the periodic mode showed two kinds of trajectories: the trochoidal motion and the longitudinal one coupled with a periodic transverse motion. For the aperiodic modes, other mechanisms appeared, such as ejection from the mixing layer, trapping by a growing vortex or merging vortices. The analysis of the local velocity field, the vortices’ shape, the spatial distribution of the forces and the ion flux components explained these trajectories. MDPI 2019-05-14 /pmc/articles/PMC6566642/ /pubmed/31091791 http://dx.doi.org/10.3390/ijms20102393 Text en © 2019 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Magnico, Pierre
Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane
title Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane
title_full Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane
title_fullStr Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane
title_full_unstemmed Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane
title_short Electro-Kinetic Instability in a Laminar Boundary Layer Next to an Ion Exchange Membrane
title_sort electro-kinetic instability in a laminar boundary layer next to an ion exchange membrane
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6566642/
https://www.ncbi.nlm.nih.gov/pubmed/31091791
http://dx.doi.org/10.3390/ijms20102393
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