Micro thermal anemometer (µTA) for turbulence measurement : development, fabrication and characterization

Baptiste Baradel (1) , Olivier Leon (1) , Alain Giani (2, 3, 4, 5) , Philippe Combette (2, 3, 4, 5) , Fabien Mery (1)

1 DMPE, ONERA, Université de Toulouse [Toulouse]
2 IES - Institut d’Electronique et des Systèmes
3 M2N - Matériaux, Micro et Nanodispositifs
4 CI - Capteurs et Instrumentations
5 FSEC - Fiabilité et Systèmes en Environnements Contraints

The present work provides details on the fabrication and the characterization of a micro thermal anemometer for measuring velocity fluctuations in turbulent flows. This device is based on a freestanding thin platinum wire of 60 µm × 0.2 µm × 1.5 µm acting as sensing element, placed in the middle of a 900 µm length bridge and supported by a silicon structure. A discussion is provided on the designing steps and the manufacturing process relying on micro fabrication techniques. A series of flow velocity measurements was conducted in a turbulent boundary layer to evaluate the response of this sensor. The results are discussed and compared with conventional hot wire anemometry measurements and semi-empirical models to highlight the relevance of this new sensor for turbulence studies.

Mots clés: High Reynolds number turbulent flows; Thermal anemometry; Micro-sensor; Boundary layer

Domaines: Sciences de l'ingénieur [physics]; Physique [physics]

Baptiste Baradel, Olivier Leon, Alain Giani, Philippe Combette, Fabien Mery. Micro thermal anemometer (µTA) for turbulence measurement : development, fabrication and characterization. 2021 Symposium on Design, Test, Integration & Packaging of MEMS and MOEMS (DTIP), Aug 2021, Paris, France. pp.01-06, ⟨10.1109/DTIP54218.2021.9568498⟩. ⟨hal-03417015⟩