Abstract
In this work it is rigorously shown that, even in the presence of highly nonlinear phenomena, provided that they belong to the thermodynamic branch, there is mathematical equivalence between the formulation of an extended thermodynamic theory with several fields where a relaxation time is successively set equal to zero and the direct formulation of a theory with a reduced number of independent fields where a constitutive relation is postulated for the eliminated field. This result is obtained as a consequence of the fact that for vanishing relaxation times of these fields the corresponding intrinsic Lagrange multipliers in the Liu procedure of Extended Thermodynamics also vanish, and of the fact that these multipliers can be chosen, together with the velocity, as global variables in Extended Thermodynamics.
Copyright (c)1999 by Walter de Gruyter GmbH & Co. KG
