Transient Conduction and Radiation Heat Transfer in Porous Thermal Insulations

Abstract

This paper analyzes transient radiation and conduction heat transfer through planar porous materials. The transient response considered is caused by a sudden increase of heat generation at the hot boundary. The objective was to establish the effect of radiation on the temperature rise of the hot wall. The problem investigated is relevant to the use of transient methods for measuring the thermal conductivity of porous insulations. It was found that, in cases such as when the porous material is a light-weight fiberglass insulation, neglecting radiation would result in serious errors in predicting the hot wall temperature rise.