Publications Internationales

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Author: search.filters.author.Bouanani, MohammedSubject: search.filters.subject.Natural convection

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    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, Mohammed
    In 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.
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    Natural convection and volumetric radiation interactions in a concentric square annulus
    (American Institute of Aeronautics and Astronautics, 2021) Bouanani, Mohammed; Benbrik, Abderrahmane; Lemonnier, Denis; Cherifi, Mohammed; Soualmi, Rabiaa
    This paper focuses on a numerical investigation of steady two-dimensional natural convection and volumetric radiation interactions in a concentric annulus between two square isothermal cylinders. The annulus is filled with a gray absorbing–emitting and non-scattering medium. All the walls are assumed to be gray, diffuse, and opaque. The dynamic and thermal interactions are studied through a finite volume method combined with an immersed boundary technique to handle the square-shaped cylinder, whereas the discrete ordinates method is used to solve the radiative transfer equation. The present study is performed to investigate the effect of volumetric radiation on the flow for a variety of Rayleigh numbers 103 –106, three different optical thicknesses τ 0.2–1–5, a variety of Planck numbers 0.01–1, and three different aspect ratios A 0.2–0.4–0.6. The analysis is based on the dynamic and thermal fields in addition to the heat transfer rate. Results show that radiation affects significantly the flow and temperature distributions for a higher Rayleigh number Ra > 104, depending on the Planck number. The optical thickness and the aspect ratio has an important impact on the Nusselt number and percentage of radiation in heat transfer
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    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, Mohammed
    This 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.