Previous Article in Journal
Constraints on Lorentz Invariance Violation from Gamma-Ray Burst Rest-Frame Spectral Lags Using Profile Likelihood
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
This is an early access version, the complete PDF, HTML, and XML versions will be available soon.
Article

Thermodynamics of Fluid Elements in the Context of Turbulent Isothermal Self-Gravitating Molecular Clouds

1
Institute of Astronomy and NAO, Bulgarian Academy of Sciences, 72 Tzarigradsko Chausee Blvd., 1784 Sofia, Bulgaria
2
Department of Applied Physics, Faculty of Applied Mathematics, Technical University-Sofia, 8 Kliment Ohridski Blvd., 1000 Sofia, Bulgaria
*
Author to whom correspondence should be addressed.
Universe 2025, 11(6), 184; https://doi.org/10.3390/universe11060184
Submission received: 28 March 2025 / Revised: 28 May 2025 / Accepted: 5 June 2025 / Published: 6 June 2025
(This article belongs to the Section Galaxies and Clusters)

Abstract

In the present work, we suggest a new approach for studying the equilibrium states of an hydrodynamic isothermal turbulent self-gravitating system as a statistical model for a molecular cloud. The main hypothesis is that the local turbulent motion of the fluid elements is purely chaotic and can be regarded as a perfect gas. Then, the turbulent kinetic energy per fluid element can be substituted for the temperature of the chaotic motion of the fluid elements. Using this, we write down effective formulae for the internal and total the energy and for the first principal of thermodynamics. Then, we obtain expressions for the entropy, the free energy, and the Gibbs potential. Searching for equilibrium states, we explore two possible systems: the canonical ensemble and the grand canonical ensemble. Studying the former, we conclude that there is no extrema for the free energy. Through the latter system, we obtain a minimum of the Gibbs potential when the macro-temperature and pressure of the cloud are equal to those of the surrounding medium. This minimum corresponds to a possible stable local equilibrium state of our system.
Keywords: molecular clouds; fluids; turbulence; self-gravity; thermodynamics molecular clouds; fluids; turbulence; self-gravity; thermodynamics

Share and Cite

MDPI and ACS Style

Donkov, S.; Stefanov, I.Z.; Kopchev, V. Thermodynamics of Fluid Elements in the Context of Turbulent Isothermal Self-Gravitating Molecular Clouds. Universe 2025, 11, 184. https://doi.org/10.3390/universe11060184

AMA Style

Donkov S, Stefanov IZ, Kopchev V. Thermodynamics of Fluid Elements in the Context of Turbulent Isothermal Self-Gravitating Molecular Clouds. Universe. 2025; 11(6):184. https://doi.org/10.3390/universe11060184

Chicago/Turabian Style

Donkov, Sava, Ivan Zh. Stefanov, and Valentin Kopchev. 2025. "Thermodynamics of Fluid Elements in the Context of Turbulent Isothermal Self-Gravitating Molecular Clouds" Universe 11, no. 6: 184. https://doi.org/10.3390/universe11060184

APA Style

Donkov, S., Stefanov, I. Z., & Kopchev, V. (2025). Thermodynamics of Fluid Elements in the Context of Turbulent Isothermal Self-Gravitating Molecular Clouds. Universe, 11(6), 184. https://doi.org/10.3390/universe11060184

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop