Molecular Extended Thermodynamics of Rarefied Polyatomic Gases with a New Hierarchy of Moments

• Main Authors: Takashi Arima, Tommaso Ruggeri
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Fluids
• Subjects: extended thermodynamics; maximum entropy principle; rarefied polyatomic gas; moments equation
• Online Access: https://www.mdpi.com/2311-5521/6/2/62

The aim of this paper is to construct the molecular extended thermodynamics for classical rarefied polyatomic gases with a new hierarchy, which is absent in the previous procedures of moment equations. The new hierarchy is deduced recently from the classical limit of the relativistic theory of moments associated with the Boltzmann–Chernikov equation. The field equations for 15 moments of the distribution function, in which the internal degrees of freedom of a molecule are taken into account, are closed with the maximum entropy principle. It is shown that the theory contains, as a principal subsystem, the previously polyatomic 14 fields theory, and in the monatomic limit, in which the dynamical pressure vanishes, the differential system converges, instead of to the Grad 13-moment system, to the Kremer 14-moment system.