Time-dependent Onsager equations and perturbation propagation

The diffusion of perturbations is investigated, beginning with Onsager-type equations for particle current and energy flow and conservation equations. This method takes into consideration the interplay of density and temperature, and the phenomena produced by this interplay—often neglected with other approaches—are fully accounted for. Time evolution of density and temperature profiles are presented. The speed of propagation of perturbation is calculated.