Laminar Natural Convection Study in a Horizontal HalfElliptical Enclosure Using Heater on Horizontal Wall

Abdelkarim  Bouras; Djedid  Taloub; Abdelhadi  Beghidja; Zied  Driss

Authors

Abdelkarim Bouras Laboratory of Energetic Physics, University brothers Mentouri Constantine1, Constantine1, Algeria
Djedid Taloub Laboratory of Renewable Energy and Sustainable Development (LRESD), University brothers Mentouri Constantine1, Algeria
Abdelhadi Beghidja Laboratory of Renewable Energy and Sustainable Development (LRESD), University brothers Mentouri Constantine1, Algeria
Zied Driss Laboratory of Electromechanical Systems (LASEM), National School of Engineers of Sfax (ENIS), University of Sfax, Sfax, Tunisia

Keywords:

thermal transfer, natural convection, circular and half-elliptical, multicellular flow, laminar flow, steady flow

Abstract

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.