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Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry
Direct measurements of the slip velocity in rarefied gas flows produced by local thermodynamic non-equilibrium at the wall represent crucial information for the validation of existing theoretical and numerical models. In this work, molecular tagging velocimetry (MTV) by direct phosphorescence is app...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2020
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7230473/ https://www.ncbi.nlm.nih.gov/pubmed/32252354 http://dx.doi.org/10.3390/mi11040374 |
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author | Fratantonio, Dominique Rojas-Cárdenas, Marcos Barrot, Christine Baldas, Lucien Colin, Stéphane |
author_facet | Fratantonio, Dominique Rojas-Cárdenas, Marcos Barrot, Christine Baldas, Lucien Colin, Stéphane |
author_sort | Fratantonio, Dominique |
collection | PubMed |
description | Direct measurements of the slip velocity in rarefied gas flows produced by local thermodynamic non-equilibrium at the wall represent crucial information for the validation of existing theoretical and numerical models. In this work, molecular tagging velocimetry (MTV) by direct phosphorescence is applied to argon and helium flows at low pressures in a 1-mm deep channel. MTV has provided accurate measurements of the molecular displacement of the gas at average pressures of the order of 1 kPa. To the best of our knowledge, this work reports the very first flow visualizations of a gas in a confined domain and in the slip flow regime, with Knudsen numbers up to 0.014. MTV is cross-validated with mass flowrate measurements by the constant volume technique. The two diagnostic methods are applied simultaneously, and the measurements in terms of average velocity at the test section are in good agreement. Moreover, preliminary results of the slip velocity at the wall are computed from the MTV data by means of a reconstruction method. |
format | Online Article Text |
id | pubmed-7230473 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2020 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-72304732020-05-22 Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry Fratantonio, Dominique Rojas-Cárdenas, Marcos Barrot, Christine Baldas, Lucien Colin, Stéphane Micromachines (Basel) Article Direct measurements of the slip velocity in rarefied gas flows produced by local thermodynamic non-equilibrium at the wall represent crucial information for the validation of existing theoretical and numerical models. In this work, molecular tagging velocimetry (MTV) by direct phosphorescence is applied to argon and helium flows at low pressures in a 1-mm deep channel. MTV has provided accurate measurements of the molecular displacement of the gas at average pressures of the order of 1 kPa. To the best of our knowledge, this work reports the very first flow visualizations of a gas in a confined domain and in the slip flow regime, with Knudsen numbers up to 0.014. MTV is cross-validated with mass flowrate measurements by the constant volume technique. The two diagnostic methods are applied simultaneously, and the measurements in terms of average velocity at the test section are in good agreement. Moreover, preliminary results of the slip velocity at the wall are computed from the MTV data by means of a reconstruction method. MDPI 2020-04-02 /pmc/articles/PMC7230473/ /pubmed/32252354 http://dx.doi.org/10.3390/mi11040374 Text en © 2020 by the authors. 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 Fratantonio, Dominique Rojas-Cárdenas, Marcos Barrot, Christine Baldas, Lucien Colin, Stéphane Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry |
title | Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry |
title_full | Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry |
title_fullStr | Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry |
title_full_unstemmed | Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry |
title_short | Velocity Measurements in Channel Gas Flows in the Slip Regime by means of Molecular Tagging Velocimetry |
title_sort | velocity measurements in channel gas flows in the slip regime by means of molecular tagging velocimetry |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7230473/ https://www.ncbi.nlm.nih.gov/pubmed/32252354 http://dx.doi.org/10.3390/mi11040374 |
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