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5–8 Sept 2023
Department of Physics, University of Coimbra
Europe/Lisbon timezone
Book of Abstracts available for download !

RAMAN THERMOMETRY OF CONFINED GAS MICRO-FLOWS

6 Sept 2023, 16:00
15m
Department of Physics, University of Coimbra

Department of Physics, University of Coimbra

R. Larga, 3004-516 Coimbra, Portugal
Oral Communication Oral communications

Speaker

Dr José M. Fernández (Instituto de Estructura de la Materia IEM-CSIC)

Description

Microfluidics devices with internal gas flows are nowadays subject of a rapid development. These devices often operate in rarefied gas flow regimes, since the ratio of the molecular mean free path over the channel dimensions becomes non-negligible. In those rarefied flows, effects like temperature-jumps near the wall are expected to occur. However, there is a lack of experimental techniques capable of measuring the internal properties, such as temperature, in gas flows confined in small channels [1].

Raman spectroscopy is a powerful non-intrusive technique to probe gas jets at the molecular level with high spatial resolution, as we have demonstrated in the Laboratory of Molecular Fluid Dynamics of the IEM [2].

Here we present a first proof-of-concept application of Raman thermometry to the gas flows within the millimetre channels. For this work, we have designed several channels with forced thermal gradients, and demonstrated that the gas temperature in the flow can be retrieved, with high spatial resolution, from the rotational and vibrational Raman spectra of molecules like N2, CO2 and acetone.

Acknowledgements
This research is funded by the Spanish Ministerio de Ciencia e Innovación, through grants No. PRE2018-085960 and PID2021-123752NB-I00.

[1] S. Colin, J.M. Fernández, C. Barrot, L. Baldas, S. Bajic, M. Rojas-Cárdenas. “Review of Optical Thermometry Techniques for Flows at the Microscale towards Their Applicability to Gas Microflows". Micromachines 13, 1819 (2022)
[2] https://www.iem.csic.es/fismol/fdm/publications.html

Authors

Dr Guzmán Tejeda (Instituto de Estructura de la Materia IEM-CSIC) Slaven Bajic (Institut Clément Ader (ICA - UMR CNRS 5312). Université de Toulouse, CNRS - IMT Mines Albi - INSA - ISAE Supaéro - UT3) Carlos Alvarez (Instituto de Estructura de la Materia IEM-CSIC) Dr José M. Fernández (Instituto de Estructura de la Materia IEM-CSIC)

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