HYPERBOLIC HEAT-CONDUCTION AND LOCAL EQUILIBRIUM - A 2ND LAW ANALYSIS

An analysis of the compatibility of Cattaneo-Vernotte's constitutive e quation for the heat flux density vector with the hypothesis of local thermodynamic equilibrium is presented. This compatibility is checked by determining the entropy production rate per unit volume. In fact, w ithin the scheme of local equilibrium, Clausius' inequality implies th at the entropy production rate must be non-negative. The evaluation of the entropy production rate is performed for a solid slab which exper iences a sudden change of the boundary temperature and for a semi-infi nite solid with a time-varying boundary heat flux. A domain of non-sta tionary phenomena is found in which Cattaneo-Vernotte's equation is co mpatible with the assumption of local equilibrium and yields results d efinitely different from those predicted by Fourier's equation. Copyri ght (C) 1996 Elsevier Science Ltd.