Simultaneous temperature and velocity Lagrangian measurements in turbulent thermal convection
| Autor: | Sergio Chibbaro, Fanny Seychelles, Julien Salort, Francesco Zonta, Jean-François Pinton, Olivier Liot, Yoann Gasteuil, Thibaut Coudarchet, Francesca Chillà |
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| Přispěvatelé: | Laboratoire de Physique de l'ENS Lyon (Phys-ENS), École normale supérieure - Lyon (ENS Lyon)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon, Laboratory for Environmental & Process Fluid Mechanics, Università degli Studi di Udine - University of Udine [Italie], Institut Jean le Rond d'Alembert (DALEMBERT), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), smartINST, École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2016 |
| Předmět: |
Physics
Convection Convective heat transfer plume/thermal Turbulence Mechanical Engineering Fluid Dynamics (physics.flu-dyn) Scalar (physics) FOS: Physical sciences Physics - Fluid Dynamics Turbulent convection Mechanics Condensed Matter Physics Tracking (particle physics) 01 natural sciences Temperature measurement 010305 fluids & plasmas Massless particle Heat flux Mechanics of Materials 0103 physical sciences [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] 010306 general physics |
| Zdroj: | Journal of Fluid Mechanics Journal of Fluid Mechanics, Cambridge University Press (CUP), 2016, 794, pp.655-675. ⟨10.1017/jfm.2016.190⟩ Journal of Fluid Mechanics, 2016, 794, pp.655-675. ⟨10.1017/jfm.2016.190⟩ |
| ISSN: | 1469-7645 0022-1120 |
| DOI: | 10.1017/jfm.2016.190 |
| Popis: | We report joint Lagrangian velocity and temperature measurements in turbulent thermal convection. Measurements are performed using an improved version (extended autonomy) of the neutrally-buoyant instrumented particle that was used by to performed experiments in a parallelepipedic Rayleigh-Benard cell. The temperature signal is obtained from a RFtransmitter. Simultaneously, we determine particle's position and velocity with one camera, which grants access to the Lagrangian heat flux. Due to the extended autonomy of the present particle, we obtain well converged temperature and velocity statistics, as well as pseudo-eulerian maps of velocity and heat flux. Present experimental results have also been compared with the results obtained by a corresponding campaign of Direct Numerical Simulations and Lagrangian Tracking of massless tracers. The comparison between experimental and numerical results show the accuracy and reliability of our experimental measurements. Finally, the analysis of lagrangian velocity and temperature frequency spectra is shown and discussed. In particular, we observe that temperature spectra exhibit an anomalous f^2.5 frequency scaling, likely representing the ubiquitous passive and active scalar behavior of temperature Comment: 15 pages, submitted |
| Databáze: | OpenAIRE |
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