J 2023

Polytropic representation of the kinetic pressure tensor of non-ideal magnetized fluids in equilibrium toroidal structures

CREMASCHINI, Claudio, Jiří KOVÁŘ, Zdeněk STUCHLÍK a Massimo TESSAROTTO

Základní údaje

Originální název

Polytropic representation of the kinetic pressure tensor of non-ideal magnetized fluids in equilibrium toroidal structures

Autoři

CREMASCHINI, Claudio (380 Itálie, domácí), Jiří KOVÁŘ (203 Česká republika, domácí), Zdeněk STUCHLÍK (203 Česká republika, domácí) a Massimo TESSAROTTO (380 Itálie, domácí)

Vydání

PHYSICS OF FLUIDS, 2023, 1070-6631

Další údaje

Jazyk

angličtina

Typ výsledku

Článek v odborném periodiku

Obor

10308 Astronomy

Stát vydavatele

Spojené státy

Utajení

není předmětem státního či obchodního tajemství

Odkazy

Kód RIV

RIV/47813059:19630/23:A0000298

Organizační jednotka

Fyzikální ústav v Opavě

UT WoS

000912154000009

Klíčová slova anglicky

Non-ideal fluids;Pressure tensors; Microscopic kinetics;Chapman-Enskog expansion;fluid plasma;accretion-disk;

Štítky

Příznaky

Mezinárodní význam, Recenzováno
Změněno: 26. 2. 2024 13:19, Mgr. Pavlína Jalůvková

Anotace

V originále

Non-ideal fluids are generally subject to the occurrence of non-isotropic pressure tensors, whose determination is fundamental in order to characterize their dynamical and thermodynamical properties. This requires the implementation of theoretical frameworks provided by appropriate microscopic and statistical kinetic approaches in terms of which continuum fluid fields are obtained. In this paper, the case of non-relativistic magnetized fluids forming equilibrium toroidal structures in external gravitational fields is considered. Analytical solutions for the kinetic distribution function are explicitly constructed, to be represented by a Chapman-Enskog expansion around a Maxwellian equilibrium. In this way, different physical mechanisms responsible for the generation of non-isotropic pressures are identified and proved to be associated with the kinetic constraints imposed on single and collective particle dynamics by phase-space symmetries and magnetic field. As a major outcome, the validity of a polytropic representation for the kinetic pressure tensors corresponding to each source of anisotropy is established, whereby directional pressures exhibit a specific power-law functional dependence on fluid density. The astrophysical relevance of the solution for the understanding of fluid plasma properties in accretion-disk environments is discussed.