Browsing by Author "Abdelkarim, Bouras"

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    Laminar Natural Convection Study in a Horizontal Half- Elliptical Enclosure Using Heater on Horizontal Wall
    (Université de M'sila, 2019) Abdelkarim, Bouras
    A numerical analysis of laminar natural convection in a horizontal annulus between an internal heated plane and an external cold half-elliptical was investigated using approximation of Boussinesq. Both internal and external walls are maintained at the constant temperature and air is the working fluid. Numerical solutions are obtained using a commercial computational fluid dynamics package, FLUENT, using the finite volume method. Effects of the Rayleigh number, Rat, on the Nusselt number, Nu, as well as velocity and temperature fields are investigated for the range of Rat from 1.0 103 to 5.0 105. The results show that for a small thermal Rayleigh number, the heat transfer within the annulus is essentially controlled by the conduction process. As the thermal Rayleigh number increases (Rat ≥ 104), the role of convection becomes predominant. Also the heat transfer rate increases. The aim of this study is to observe the effects of thermal Rayleigh numberon the structure of the flow and the distribution of the temperature.
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    Natural convective heat transfer from a heated horizontal elliptical cylinder to its coaxial square enclosure
    (Université de M'sila, 2018-12) Abdelkarim, Bouras
    A numerical study of the natural convection of laminar heat transfer in the stationary state in a horizontal annular space between a heated square inner cylinder and a cold elliptical outer cylinder was investigated. This annular space is traversed by a Newtonian and incompressible fluid. The Prandtl number is set to 0.71 (air case) for different Rayleigh numbers. The governing equations of the problem were solved numerically by the commercial code Fluent, based on the finite volume method and the Boussinesq approximation. The inner and outer surfaces are isothermal. The study was performed for Rayleigh numbers ranging from 1.3 × 103 to 5.5× 105. Particularly, we have studied the effects of different thermal Rayleigh numbers on natural phenomenon convection. The results were presented in the form of isotherms, streamlines, and local and average Nusselt numbers. The purpose of this study is to observe the influence of the thermal Rayleigh number on the structure of the flow and distribution of the temperature.