Prof. Ramadan Youssef Sakr Moustafa :: Publications:

A numerical investigation of natural convection inside eccentric horizontal annulus filled with saturated porous medium is carried out. The solution scheme is based on two-dimensional model, which is governed by Darcy-Oberbeck-Boussinseq equation. The inner cylinder is heated isothermally while the outer one is cooled isothermally. Discretization of the governing equations is achieved using finite element scheme based on Galerkin method of weighted residuals. The effect of pertinent parameters such as the modified Rayleigh number (Ra) and the relative eccentricity for radius ratio of 2 are considered in this study. The modified Rayleigh number ranges from 10 to 400 while the relative eccentricity () ranges from 0.1 to 0.8. The effect of eccentricity direction is also studied by making runs for eccentricity in horizontal, vertical, 45o and 315o orientation. The numerical results obtained from the present model are compared with the available published results and a good agreement was found. The average Nusselt number and heat transfer as a function of Rayleigh number is presented. Also the flow and heat transfer characteristics are illustrated in terms of stream function and isotherms.