In this paper we attempt to study the effect of the entropy flux of Muller and of the inclusion of other constitutive variables on the new heat equation, which is capable of predicting a finite velocity of propagation of the heat disturbance, and the form of the stress tensor. We define a new free energy function. The heat equation obtained is shown to be a generalisation of some obtained so far. It turns out that the inclusion of the constitutive variables T, the material time derivative of the temperature and the velocity gradient may be necessary and the adoption of Muller’s new entropy flux in thermoelastic materials explored.
International Journal of Engineering Science 12/1984; 22(5-22):503-517. DOI:10.1016/0020-7225(84)90053-3