Effect of thermal conductivity and emissivity of solid walls on time-dependent turbulent ...

Conjugate turbulent free convection with thermal surface radiation in a rectangular enclosure bounded by walls with different thermophysical characteristics in the presence of a local heater has been numerically studied. The effects of surface emissivity and wall materials on the air flow and heat transfer characteristics were the main focus of the present investigation. Conjugate convective heat transfer for the fluid (air), described in terms of linear momentum, continuity and energy equations combined with k-ε turbulence model, was predicted by using the finite difference method. Results for the isotherms, streamlines and average Nusselt numbers along the heat source are presented. The numerical experiments showed that an increase in thermal conductivity of solid walls illustrates the enhancement of heat transfer. Eventually, the main result obtained in this work provides good technical support for the development and research of energy-efficient building materials.