Indoor Turbulent Natural Convection Heat Transfer with Thermal Radiation in Rooms with Porous Building Envelopes

Numerical analysis is undertaken of turbulent natural convection heat transfer with thermal radiation in enclosures. The objective is to investigate the turbulent natural heat transfer characteristics for rooms considering surface thermal radiation on the inner walls. A finite-element method was used to numerically solve the governing equations in the two regions. It was found that with the increase of Rayleigh number, Ra, the Nusselt numbers on the inner wall increase; surface thermal radiation can significantly change the temperature fields in both the regions of air flow and porous medium. The mean temperature at the interface decreases with increase of the surface emissivity. The mean convective, radiative and total Nusselt numbers show different trends at the interface with several emissivities. The Nuc at the interface decrease with increase of thickness of porous media until d >= 0.25, and there is no change in Nuc as d is further increased. (C) 2017 The Authors. Published by Elsevier Ltd.