On-site airflow measurement of a laboratory fume hood using customized large-scale image-based velocimetry

Romain Schuster (1) , Dominique Heitz (2, 3, 4) , Philippe Georgeault (3) , Etienne Mémin (2)

1 ITGA - Institut Technique des Gaz et de l'Air
2 FLUMINANCE - Fluid Flow Analysis, Description and Control from Image Sequences
3 UR OPAALE - Optimisation des procédés en Agriculture, Agroalimentaire et Environnement
4 IRMAR - Institut de Recherche Mathématique de Rennes

This study demonstrates the feasibility of conducting on-site large-scale image-based measurements for indoor airflows characterization. We chose to study the suction flow generated by a laboratory fume hood in operating conditions. As a matter of fact laboratory fume hoods are frequently subject to routine checks during which air speed measurements by hot-wire anemometry are performed. However classical point-to-point hot-wire anemometry may not be sufficient to detect and localize potential leakages. To improve these controls we developed and tested a new method based on particle image velocimetry principles, which is non-intrusive and authorizes a good spatio-temporal analysis. To face large-scale and on-site issues we had to make some adaptations. For this reason, we used tracers like bubbles or smoke which have good scattering properties. We also developed our own low-cost light system. To compute velocities from image sequences we developed an optical flow algorithm based on a large-scale flow model instead of using traditional correlation. The tested method gave good results with a good agreement with sparse HWA measurements but with a wider spatial distribution. In addition the method provided turbulence intensity estimation and a good monitoring of dynamic flow features, which is important for leakages detection.

Mots clés: large-scale PIV; optical flow; fume hood

Domaines: Modélisation et simulation; Mécanique des fluides [physics.class-ph]; Traitement du signal et de l'image [eess.SP]

Romain Schuster, Dominique Heitz, Philippe Georgeault, Etienne Mémin. On-site airflow measurement of a laboratory fume hood using customized large-scale image-based velocimetry. Roomvent & Ventilation 2018, Jun 2018, Espoo, Finland. pp.1-6. ⟨hal-01957995⟩