Review of optical thermometry techniques for flows at the microscale towards their applicability to gas microflows

Stéphane Colin (1, 2) , José M Fernández (3) , Christine Barrot-Lattes (1) , Lucien Baldas (1) , Slaven Bajić (1) , Marcos Rojas-Cárdenas (1)

1 ICA - Institut Clément Ader
2 FERMAT - Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts
3 IEM - Instituto de Estructura de la Materia

Thermometry techniques have been widely developed during the last decades to analyze thermal properties of various fluid flows. Following the increasing interest for microfluidic applications, most of these techniques have been adapted to the microscale and some new experimental approaches have emerged. In the last years, the need for a detailed experimental analysis of gaseous microflows has drastically grown due to a variety of exciting new applications. Unfortunately, thermometry is not yet well developed for analyzing gas flows at the microscale. Thus, the present review aims at analyzing the main currently available thermometry techniques adapted to microflows. Following a rapid presentation and classification of these techniques, the review is focused on optical techniques, which are the most suited for application at microscale. Their presentation is followed by a discussion about their applicability to gas microflows, especially in confined conditions, and the current challenges to be overcome are presented. A special place is dedicated to Raman and molecular tagging thermometry techniques due to their high potential and low intrusiveness.

Mots clés: thermometry; gas microflow; microsystem; microfluidics; temperature; rarefaction

Domaines: Mécanique des fluides [physics.class-ph]; Micro et nanotechnologies/Microélectronique; Instrumentations et Détecteurs [physics.ins-det]

Stéphane Colin, José M Fernández, Christine Barrot-Lattes, Lucien Baldas, Slaven Bajić, et al.. Review of optical thermometry techniques for flows at the microscale towards their applicability to gas microflows. Micromachines, 2022, 13 (11), pp.1819. ⟨10.3390/mi13111819⟩. ⟨hal-03828737⟩