Chapter 2 - Lagrange Formalism and Irreversible Thermodynamics: The Second Law of Thermodynamics and the Principle of Least Entropy Production

Abstract

This chapter discusses the traditional thermodynamics of irreversible processes (TIP) and explains the principle of Least Entropy Production. This principle is verified for stationary processes of very special systems only. A general formulation of the principle is still missing. In Lagrange formalism as applied to TIP, a general concept of entropy is involved in quite a natural and straightforward way. It is defined by an inhomogeneous balance equation—the Second Law of Thermodynamics—which essentially results from a universal structure of Lagrange formalism and from the invariance of the Lagrangian, with respect to a group of common gauge transformations applied to complex-valued fundamental field variables of the thermo-dynamical system. Within Lagrange formalism a general Principle of Least Entropy Production is associated with the entropy concept. On the background of the traditional, very confined concept, the general concept in Lagrange formalism is presented.