Publications Internationales
Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/13
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Item A Numerical Study on the Effect of Radiation on Natural Convection in a Two-Square Duct Annuli Filled with a Semi-Transparent Fluid(IJME, 2023) Bouanani, Mohammed; Benbrik, Abderrahmane; Soualmi, Rabiaa; Cherifi, MohammedIn the present study, a numerical investigation of natural convection and volumetric radiation interactions has been analysed in an annulus between two isothermal concentric square ducts filled with a semi-transparent medium. Two-dimensional solution was obtained using a discrete ordinates method based on a combined finite volume-immersed boundary method. The fluid is assumed to be gray absorbing-emitting and non-scattering and all walls are gray, diffuse and opaque. The Rayleigh number is fixed to 106 , and a study of the effect of three optical thicknesses τ=0.2-1-5 is performed on the thermal and dynamic fields and consequently on the heat transfer rate has been examined. A pure natural convection case has been shown for a comparative study. It is found that the radiation has a large influence on the flow and surface averaged Nusselt number and especially for high Rayleigh numbers.Item A hybrid scheme of single relaxation time lattice Boltzmann and finite volume methods coupled with discrete ordinates method for combined natural convection and volumetric radiation in an enclosure(2020) Soualmi, R; Benbrik, A.; Lemonnier, D.; Cherifi, M.; Bouanani, MohammedThis paper is focused on the application of hybrid Single relaxation time lattice Boltzmann and finite volume methods in conjunction with discrete ordinates method to simulate coupled natural convection and volumetric radiation in differentially heated enclosure, filled with an absorbing, emitting and non - scattering gray medium. In this work, the velocity and temperature fields are calculated using lattice Boltzmann and finite volume methods respectively, whereas the radiative term is computed by the discrete ordinates method. This study is carried out for Pr = 0.71 , a Rayleigh n umber range of 10 3 ≤ Ra ≤ 10 6 , an optical thickness with values 0 ≤ τ ≤ 100, a Planck number ranging in 0.001≤ Pl ≤ 100 and an aspect ratio varying between 0.5 ≤ Ar ≤ 2. Results are presented in terms of streamlines, isotherms, velocity profiles and averag e Nusselt number. Based on the obtained results, it can be concluded that the presence of volumetric radiation is noteworthy. Its effect, as a function of Rayleigh number and the radiative properties, yields significant changes on the behavior of streamlin es and isotherms. In the taller enclosure, the increase of average total Nusselt number with increasing Rayleigh number is less significant than that in the case of the shallow enclosure.
