Nonequilibrium theories of rarefied gases: internal variables and extended thermodynamics
Abstract
Limits of classical constitutive laws such as Fourier and NavierStokes equations are discovered since decades. However, the proper extensions—generalizations of these—are not unique. They differ in the underlying physical principles and in modeling capabilities. In this paper, two different theories are discussed and compared to each other, namely the kinetic theorybased rational extended thermodynamics (RET) and nonequilibrium thermodynamics with internal variables (NETIV). First, the paper starts with the case of rigid heat conductors summarizing the result achieved so far. Then, a typical example of compressible bodies is shown by presenting the first generalization for rarefied gases, called Meixner's theory. It is further extended using generalized entropy current in the framework of NETIV. It is shown how its structure is related to RET and how the compatibility between them can be acquired.
 Publication:

Continuum Mechanics and Thermodynamics
 Pub Date:
 May 2020
 DOI:
 10.1007/s0016102000888y
 arXiv:
 arXiv:1812.10355
 Bibcode:
 2020CMT...tmp...41K
 Keywords:

 Rarefied gases;
 Rational extended thermodynamics;
 Nonequilibrium thermodynamics;
 Internal variables;
 Condensed Matter  Statistical Mechanics
 EPrint:
 Continuum Mechanics and Thermodynamics, online first, 2020