Nonequilibrium lagrange multipliers and heat-flux saturation

The aim of this paper is to explore the physical interpretation of the Lagrange multiplier conjugate to the heat flux in the theoretical information description of nonequilibrium steady states characterized by a nonvanishing heat flux. We show that extrapolation to the nonlinear regime of the interpretation of this coefficient used in extended irreversible thermodynamics (EIT) leads to an effective or equivalent thermal conductivity which yields a saturation of heat flux when VT is important. We compare our result with other models for flux-limiters previously proposed in the literature. © Copyright 1995 Walter de Gruyter-Berlin. New York