Abstract
Using a classical irreversible thermodynamics of internal variables (CIT-IV) with Ciancio’s procedure, viscous-inelastic flow relations have been derived by generalizing the Duhamel-Neumann law for ordinary thermoelastic phenomena in isotropic media and the relations for elastic media and for Maxwell, Jeffreys and Poynting-Thomson bodies. Furthermore, a heat equation with two relaxation times has been derived that generalizes the Fourier and Maxell-Catteno-Vernotte (MCV) equations without having to introduce assumptions that are non found sense in physics. In this paper the authors not only apper to be effective from a mathematical point of view but is direct in physical applications. In this context, through the simple description of the ultra-fast process of energy transmission from a laser source to metal film, using the principles of thermodynamics, the heat equation is derived in the case of isotropic viscoanelastic media subject to constant strain. The solution, obtained numerically with the finite element method, not only highlights the physical significance of the phenomenological coefficients, but also specifies the limits of the previous theories of the MCV.