Three-dimensional velocity near-wall measurements by digital in-line holography: calibration and results
| Autor: | Bertrand Lecordier, D. Allano, Gilles Godard, Jean-Marc Foucaut, Frédéric Corbin, Françoise Walle, Sébastien Coëtmellec, Mokrane Malek, Denis Lebrun |
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| Přispěvatelé: | Complexe de recherche interprofessionnel en aérothermochimie (CORIA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Laboratoire de Mécanique de Lille - FRE 3723 (LML), Université de Lille, Sciences et Technologies-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université de Lille, Sciences et Technologies-Ecole Centrale de Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Physics
business.industry [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment 010401 analytical chemistry Holography Physics::Optics Fluid mechanics Laser 01 natural sciences Atomic and Molecular Physics and Optics Displacement (vector) 0104 chemical sciences law.invention 010309 optics Boundary layer Optics law 0103 physical sciences Shear stress Electrical and Electronic Engineering business Engineering (miscellaneous) Digital holography Wind tunnel |
| Zdroj: | Applied optics Applied optics, Optical Society of America, 2013, 52 (1), pp.A9-A17. ⟨10.1364/AO.52.0000A9⟩ |
| ISSN: | 0003-6935 1539-4522 |
| DOI: | 10.1364/AO.52.0000A9⟩ |
| Popis: | International audience; Velocity measurements in the vicinity of an obstacle remain very complicated even when optical diagnostics based on displacement of micrometric tracers are considered. In the present paper, digital in-line holography with a divergent beam is proposed to measure the three-dimensional (3D) velocity vector fields in a turbulent boundary layer and, in particular, on the near wall region of a wind tunnel. The seeding droplets (1-5 μm) transported by a turbulent airflow are illuminated by a couple of laser pulses coming from a fiber coupled laser diode. These double exposure holograms are then recorded through a transparent glass reticle specially designed for this application with an accurate surface positioning combined with a particularly attractive in situ calibration method of the investigation volume (less than 10 mm3). The method used for processing holograms recorded in such a configuration is detailed. Our original calibration procedure and the assessment of its accuracy are presented. Our holographic probe has been tested in a wind tunnel for a large range of different velocities. Then 3D velocity vector fields extracted from more than 13000 holograms are analyzed. Statistical results show the capability of our approach to access in a turbulent boundary layer. In particular, it leads to relevant measurements for fluid mechanics such as velocity fluctuation and the shear stress in the very close vicinity of a wall. |
| Databáze: | OpenAIRE |
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