Natural convection from horizontal noncircular annulus partially filled with porous sleeve

In this paper natural convection heat transfer within a two-dimensional, horizontal, concentric cam shape cylinders that is partially filled with a fluid saturated porous medium has been investigated. both cylinder are kept at constant and uniform temperatures with the outer cylinder being subjected relatively lower than the inner one. In addition the forchheimer and brinkman effect are taken into consideration inside the porous sleeve. furthermore, the local thermal equilibrium condition is take into account. the porosity factor is considered to be uniform and constant with ε = 0.9. the main objective of this study is to examine the effects of stream line shape, thermal conductivity ratio (ks/kf) and the porous layer thickness on the bouyancy induced flow motion under steady state condition. these effects are studied using the following dimensionless parameters: Ra = 104-106, Da = 10-3-10-5. The results show’s that Nusselt number is affected mostly by porous sleeve thickness and Rayleigh number respectively.