The General Exact Solution for the Many Moments Macroscopic Approach to Extended Thermodynamics of Polyatomic Gases

Abstract

A new model for Polyatomic and for Dense Gases has been proposed in literature in the last five years in the framework of Extended Thermodynamics. The case with an arbitrary but fixed number of moments has been recently studied, both with the kinetic approach than with the macroscopic approach; this last one is more general and includes the results of the kinetic approach only as a particular case.Scope of the "closure problem" is to find the expression of some arbitrary functions which appear in the balance equations. Up to now only a recurrence procedure has been published which outlines how to find the solution of this problem with the macroscopic approach; by using this procedure, a numberable set of solutions has been found and written explicitly, while we find here the most general exact solution. It is determined except for some arbirary terms and it is interesting that these terms appear also in the 24 moments model; so we find here that they are transmitted from the model with 24 moments to those with an arbitrary number of moments, without any further arbitrary term.

A New Model for Polyatomic Gases in an Electromagnetic Field

“…The goal of the present article is to find the corresponding results for Maxwell's equations coupled with those of the material. To this end, we take advantage of the new knowledges appeared recently in literature for polyatomic gases such as, Pavi´c et al (2013), Arima et al (2012 and, , Ruggeri and Sugiyama (2015), , , Carrisi et al ( , 2017Carrisi et al ( , 2020; Ruggeri (2017, 2020); Pennisi (2021); Ruggeri and Sugiyama ( 2021) but, as first step, we consider only the Euler equations for describing the contribute of the material. So the whole set of field equations here considered is…”