Entropy 2012, 14, 92-130; doi:10.3390/e14020092 OPEN ACCESS entropy ISSN 1099-4300 www.mdpi.com/journal/entropy Article The Rate-Controlled Constrained-Equilibrium Approach to Far-From-Local-Equilibrium Thermodynamics Gian Paolo Beretta 1;?, James C. Keck 2;y, Mohammad Janbozorgi 3 and Hameed Metghalchi 3 1 Department of Mechanical and Industrial Engineering, Universita` di Brescia, Brescia, 25123, Italy 2 Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 3 Department of Mechanical Engineering, Northeastern University Boston, MA 02115, USA; E-Mails:
[email protected] (M.J.);
[email protected] (H.M.) y Deceased. ? Author to whom correspondence should be addressed; E-Mail:
[email protected]. Received: 12 October 2011; in revised form: 31 December 2011 / Accepted: 18 January 2012 / Published: 30 January 2012 Abstract: The Rate-Controlled Constrained-Equilibrium (RCCE) method for the description of the time-dependent behavior of dynamical systems in non-equilibrium states is a general, effective, physically based method for model order reduction that was originally developed in the framework of thermodynamics and chemical kinetics. A generalized mathematical formulation is presented here that allows including nonlinear constraints in non-local equilibrium systems characterized by the existence of a non-increasing Lyapunov functional under the system’s internal dynamics. The generalized formulation of RCCE enables to clarify the essentials of the method and the built-in general feature of thermodynamic consistency in the chemical kinetics context. In this paper, we work out the details of the method in a generalized mathematical-physics framework, but for definiteness we detail its well-known implementation in the traditional chemical kinetics framework.