DOUBLE CONDUCTIVITY MEDIA - A COMPARISON BETWEEN PHENOMENOLOGICAL ANDHOMOGENIZATION APPROACHES

The heat transfer model for the double conductivity medium is investig ated. The medium is composed of two homogeneous materials which differ considerably in their conductivity characteristics. The aim of this p aper is to compare the descriptions obtained by a phenomenological and a homogenization approach. The first one, which introduces two temper ature fields, is shown to be inefficient for a large range of the phen omena. The latter gives the rigorous description. The study enables us to improve the phenomenological description. It provides an approxima tion which is valid for the quasi-static conditions.