Numerical Investigation of Natural Convection in Horizontal Porous Media Heated from Below—Comparisons with Experiments

Abstract

Thick layers of highly permeable loose-fill insulation are used to thermally insulate attics in modern building technology. Since the use of highly permeable insulation leads to an increase in air movement not only in the porous layer (insulation) but also in the fluid layer (attics), it is therefore of paramount interest to determine the influence of the complex heat transfer phenomena due to natural and forced convection on the thermal properties of insulating porous medium with air cavity. With the help of CFD (Computational Fluid Dynamics), the combined effect of air movement inside the insulation and the air cavity is investigated. The paper deals with the CFD analysis, carried out in order to predict the effects of natural convection on the thermal performance of the building envelope. The results obtained from the numerical computations are compared with experimental findings.