NON-LINEAR HEAT WAVES IN EXTENDED IRREVERSIBLE THERMODYNAMICS

A variational approach to nonlinear heat waves in solids within extended irreversible thermodynamics is presented. The formalism gives a nonlinear in time evolution equation for the heat flux in a rigid solid which, together with the energy balance, describes in closed form the nonequilibrium processes which occur in a time scale comparable to the relaxation time of the heat flux. Well known results of heat transport are recovered in the appropriate limits by the structure of the equation which also allows for couplings not considered up until now whose consequences remain to be assessed.