Natural Convection in an Attic-Shaped Space Filled With Porous Material

Abstract

This article reports an analytical study of natural convection in a wedge-shaped horizontal space filled with a fluid-saturated porous medium. The study focuses on the detrimental effect of natural convection on the insulation value of an attic-shaped porous layer in “winter” conditions (cold roof, warm ceiling). The study reveals the most basic features of the temperature field and flow pattern established in the porous layer. The study addresses two distinct flow regimes: (a) the shallow attic limit (H/L→0, RaH = finite, but fixed) and (b) the boundary layer regime which consists of a boundary layer driven by the sloped (roof) wall plus a core flow moving slowly along the horizontal (ceiling) wall. Heat-transfer results are developed for both flow regimes.