Acceleration Waves in Rational Extended Thermodynamics of Rarefied Monatomic Gases

Abstract

Rational Extended Thermodynamics theories with different number of moments are usually introduced to study non-equilibrium phenomena in rarefied gases. Here, we use them to describe one-dimensional acceleration waves in a rarefied monatomic gas. In particular, we focus on the degeneracy of the acceleration wave to a shock wave, in order to test the validity of the models and the role played by an increasing number of moments. As a byproduct, some peculiarities of the characteristic velocities at equilibrium are analyzed as well.

Acceleration waves and oscillating gas bubbles modelled by rational extended thermodynamics

“…The behaviour of planar AWs in monatomic rarefied gases described by RET was already studied in many cases [8][9][10][11] and there is also a preliminary analysis for a polytropic gas described by a RET system with only six fields [15]. All the results confirm that shock formation is physically unlikely.…”

“…AWs can be generated in different materials and a large literature is devoted to this topic and to its application. For the sake of brevity, we quote here only some works related to gases [4][5][6][7][8][9][10][11] (and the references therein). In gases, AWs are produced by a perturbation, which could be caused for instance by a piston during its accelerated motion.…”