Heat transfer in a gas-cooled, heat-generating porous solid

Abstract

The use of porous materials in heat transfer has been increasing. The equations which. describe heat transfer in porous materials with a fluid flowing through the pores of the material are more complicated than those for heat transfer through solids and into fluids at a plane interface. Calculations of heat transfer in porous materials have been hindered by fairly widespread misconceptions about this type of heat transfer and by the lack of experimental data on the heat transfer related properties of porous materials. Among articles which have been published that discuss heat transfer in porous materials, there are some which are now acknowledged to contain errors. The erroneous conclusion of these articles, and other reasons, have fostered an assumption that in a fluid cooled porous material the solid and fluid phase temperatures will be nearly identical. The purpose of this study was to determine if an experimental apparatus could be built that could be used for gas phase chemical reactions in electrically heated porous tungsten and also to measure the heat transfer coefficient in the porous tungsten using nitrogen or helium gas as the coolant.