Hyperbolic heat conduction with variable relaxation time

There are several competing phenomenological models for the propagation of heat pulses. The semi-empirical heat conduction model uses the internal variable approach. It was previously shown that this model is in accordance with observed behaviour. The aim of the present paper is to choose material functions in a way to obtain good quantitative agreement with experimental data over the whole admissible temperature range. New approximations of experimental data are introduced and discussed together with the Clausius-Duhem inequality. The new model is verified by numerical results.