Influence of surface radiation on the transition to unsteadiness for a natural convection flow in a differentially heated cavity

Autor:	Paul Chorin, Denis Lemonnier, Didier Saury, Florian Moreau, Yann Billaud
Přispěvatelé:	Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Mécanique et d'Aérotechnique [Poitiers] (ISAE-ENSMA), Convection, Optimisation, Systèmes Thermiques (COST ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Rok vydání:	2020
Předmět:	Surface (mathematics) Numerical Analysis Materials science Natural convection Natural convection flow 02 engineering and technology Square cavity Mechanics Radiation Condensed Matter Physics 01 natural sciences [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] 010305 fluids & plasmas Physics::Fluid Dynamics 020303 mechanical engineering & transports 0203 mechanical engineering 0103 physical sciences [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph] Adiabatic process ComputingMilieux_MISCELLANEOUS
Zdroj:	Numerical Heat Transfer, Part A Applications Numerical Heat Transfer, Part A Applications, Taylor & Francis, 2020, 78 (7), pp.291-305. ⟨10.1080/10407782.2020.1791550⟩
ISSN:	1521-0634 1040-7782
Popis:	International audience; The influence of surface radiation on the transition to the unsteady state in natural convection is studied numerically. The configuration of the differentially heated square cavity with adiabatic horizontal walls is chosen to generate an internal natural convection flow. It is known that radiative transfers reduce the temperature difference between the adiabatic walls, which consequently reduces the thermal stratification of the central zone and increases the velocity flow. Many studies have focused on the stationary regime, but few of them have investigated the transition to unsteady flow. For this purpose, the effect of the wall emissivity on the critical Rayleigh number and the associated critical frequency was studied for a given cavity length. The cavity length and mean temperature of isothermal walls are set for the whole study. The results show that all these values are between the values obtained without radiation and those obtained for perfectly conducting horizontal walls. The critical Rayleigh number decreases with emissivity while the associated frequency increases. Moreover, the symmetry of fluctuating properties of the flow is changed when the radiation is taken into account.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::cb1b16922b6c6084923f76894f78feb2 https://doi.org/10.1080/10407782.2020.1791550 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
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