Low Rayleigh Number Thermal Convection in a Saturated Porous Medium Bounded by Two Horizontal, Eccentric Cylinders

Abstract

A two-term regular perturbation expansion is presented for two-dimensional, steady-state thermal convection in a fully saturated porous medium bounded by two horizontal, eccentric cylinders. Both cylinders are impermeable to fluid motion and are maintained at different, uniform temperatures. The complicated boundary conditions are handled through the use of bicylindrical coordinates. Three geometrical configurations are considered: an eccentric annulus; a pipe buried in a semi-infinite medium; and two cylinders, one outside the other, imbedded in an infinite medium. Detailed results, however, are presented only for the first case. It is demonstrated that eccentric insulations may be more effective under certain conditions and therefore more economical than the currently used concentric ones.