{"title":"Measurements of diffusion coefficient and kinetic diameter of acetone vapor via molecular tagging","authors":"Zongwei Zhang, Dominique Fratantonio, Christine Barrot Lattes, Marcos Rojas-Cardenas, Stéphane Colin","doi":"10.1007/s10404-024-02754-8","DOIUrl":null,"url":null,"abstract":"<div><p>The Molecular Tagging (MT) technique is a promising methodology for locally measuring velocity and temperature fields in rarefied gas flows. Recently, Molecular Tagging Velocimetry (MTV) has been successfully applied to gas flows in mini-channels in the continuum regime at high pressure and early slip-flow regime at lower pressure. As the operating pressure decreases, diffusion effects become more pronounced, and in MTV, they hinder the extraction of the correct velocity profile by simply dividing the displacement profile of the tagged molecular line by time of flight. To address this issue, a reconstruction method that considers Taylor dispersion was previously developed to extract the velocity profile, considering the diffusion effects of the tracer molecules within the carrier gas. This reconstruction method successfully extracted the correct velocity profile in the continuum flow regime. However, the method still faces challenges in the slip-flow regime. Since there is currently no consensus in the literature regarding the kinetic diameter value of acetone vapor, the diffusion coefficient estimation is uncertain especially at low pressures. This is why, in this study, we propose an original optical method to measure the diffusion coefficient of acetone vapor. This is achieved by linking the temporal evolution of the spatial photoluminescence distribution of acetone vapor to the diffusion coefficient via the Chapman-Enskog theory. Our research provides measurements of these parameters for a wide range of pressures (0.5–10 kPa) at ambient temperature.</p></div>","PeriodicalId":706,"journal":{"name":"Microfluidics and Nanofluidics","volume":"28 9","pages":""},"PeriodicalIF":2.3000,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10404-024-02754-8.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Microfluidics and Nanofluidics","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s10404-024-02754-8","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"INSTRUMENTS & INSTRUMENTATION","Score":null,"Total":0}
引用次数: 0
Abstract
The Molecular Tagging (MT) technique is a promising methodology for locally measuring velocity and temperature fields in rarefied gas flows. Recently, Molecular Tagging Velocimetry (MTV) has been successfully applied to gas flows in mini-channels in the continuum regime at high pressure and early slip-flow regime at lower pressure. As the operating pressure decreases, diffusion effects become more pronounced, and in MTV, they hinder the extraction of the correct velocity profile by simply dividing the displacement profile of the tagged molecular line by time of flight. To address this issue, a reconstruction method that considers Taylor dispersion was previously developed to extract the velocity profile, considering the diffusion effects of the tracer molecules within the carrier gas. This reconstruction method successfully extracted the correct velocity profile in the continuum flow regime. However, the method still faces challenges in the slip-flow regime. Since there is currently no consensus in the literature regarding the kinetic diameter value of acetone vapor, the diffusion coefficient estimation is uncertain especially at low pressures. This is why, in this study, we propose an original optical method to measure the diffusion coefficient of acetone vapor. This is achieved by linking the temporal evolution of the spatial photoluminescence distribution of acetone vapor to the diffusion coefficient via the Chapman-Enskog theory. Our research provides measurements of these parameters for a wide range of pressures (0.5–10 kPa) at ambient temperature.
期刊介绍:
Microfluidics and Nanofluidics is an international peer-reviewed journal that aims to publish papers in all aspects of microfluidics, nanofluidics and lab-on-a-chip science and technology. The objectives of the journal are to (1) provide an overview of the current state of the research and development in microfluidics, nanofluidics and lab-on-a-chip devices, (2) improve the fundamental understanding of microfluidic and nanofluidic phenomena, and (3) discuss applications of microfluidics, nanofluidics and lab-on-a-chip devices. Topics covered in this journal include:
1.000 Fundamental principles of micro- and nanoscale phenomena like,
flow, mass transport and reactions
3.000 Theoretical models and numerical simulation with experimental and/or analytical proof
4.000 Novel measurement & characterization technologies
5.000 Devices (actuators and sensors)
6.000 New unit-operations for dedicated microfluidic platforms
7.000 Lab-on-a-Chip applications
8.000 Microfabrication technologies and materials
Please note, Microfluidics and Nanofluidics does not publish manuscripts studying pure microscale heat transfer since there are many journals that cover this field of research (Journal of Heat Transfer, Journal of Heat and Mass Transfer, Journal of Heat and Fluid Flow, etc.).