Article
Physics, Fluids & Plasmas
Takashi Arima, Tommaso Ruggeri
Summary: This paper aims to construct a new hierarchy of molecular extended thermodynamics for classical rarefied polyatomic gases, incorporating internal degrees of freedom, by deducing a new hierarchy from the classical limit of relativistic theory of moments. The field equations for 15 moments of the distribution function are closed with the maximum entropy principle, showing convergence to the Kremer 14-moment system in the monatomic limit.
Article
Mechanics
Takashi Arima, Maria Cristina Carrisi, Sebastiano Pennisi, Tommaso Ruggeri
Summary: Inspired by Pennisi (2021) in the relativistic framework, this study proposes a new natural physical hierarchy of moments to describe classical rarefied non-polytropic polyatomic gas within the framework of Molecular Rational Extended Thermodynamics. By considering the case of 15 moments and utilizing the variational method of the Maximum Entropy Principle, the system is closed and the convexity of entropy is proven, with the possibility of putting the system in symmetric form. This richer kinetic framework may have potential applications in biomathematics and other fields where kinetic models have been successfully applied recently.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2021)
Article
Mechanics
M. C. Carrisi, S. Pennisi
Summary: In this article, the relativistic Anderson-Witting model is generalized to polyatomic gases based on the moment closure approach proposed by Cercignani and Kremer for monatomic gases. A comparison is made with a model proposed by Pennisi and Ruggeri, showing that the balance equations and collision terms are equivalent up to first order in equilibrium.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2021)
Article
Thermodynamics
Giuseppe Ali, Giovanni Mascali, Oreste Pezzi, Francesco Valentini
Summary: We propose an extended hydrodynamical model that uses moments of the electron distribution function to describe the behavior of plasmas, satisfying the Fokker-Planck-Landau transport equation. The moments are obtained by multiplying the FPL equation by weight functions and integrating over velocity space. Closure relations for fluxes and production terms can be determined using the maximum entropy distribution function, which depends on Lagrangian multipliers. In this study, we focus on the 13-moment system and apply it to the relaxation process of a homogeneous plasma with temperature anisotropy, obtaining results consistent with the Kogan solution of the kinetic equation.
CONTINUUM MECHANICS AND THERMODYNAMICS
(2023)
Article
Physics, Multidisciplinary
Takashi Arima, Maria Cristina Carrisi, Sebastiano Pennisi, Tommaso Ruggeri
Summary: A relativistic extension of thermodynamics for polyatomic gases is proposed, taking into account the total energy of the system and the internal mode energy of molecules. Moment equations associated with the Boltzmann-Chernikov equation are derived and a closed system of equations is obtained. The system satisfies the entropy principle, making it symmetric hyperbolic and well-posed. The ultra-relativistic and classical limits are also studied, and subsystems with 14 and 6 moments are derived.
Article
Thermodynamics
Andrea Mentrelli, Tommaso Ruggeri
Summary: An investigation on the features of the shock structure solution of the 13-moment system of extended thermodynamics with a second-order closure based on the maximum entropy principle is presented. The analysis shows that adopting a second-order closure results in a significantly reduced subshock strength and better agreement with results obtained with the kinetic theory approach. Preliminary results for the 14-moment system of a polyatomic gas are also presented.
CONTINUUM MECHANICS AND THERMODYNAMICS
(2021)
Article
Mathematics, Applied
Andrea Mentrelli
Summary: When using higher order closures, the strength of the subshock in the shock structure is significantly reduced for large Mach numbers compared to first order closure, leading to a better agreement with experimental results in the overall profile of the shock structure solution.
RICERCHE DI MATEMATICA
(2021)
Article
Physics, Fluids & Plasmas
Jonathan Asher Pachter, Ken A. Dill
Summary: Important models in nonequilibrium statistical physics often make use of a commonly used, but frequently overlooked, near-equilibrium approximation. However, this approximation fails to hold in far-from-equilibrium systems. A more principled approach would involve deriving corrections for rate fluctuations from an underlying dynamical model, rather than assuming a particular form. Applying maximum caliber as the underlying principle, we derive such corrections for non-equilibrium processes, particularly important for heavily driven systems.
Article
Multidisciplinary Sciences
Saman Hanif Shahbaz, Aisha Fayomi
Summary: This paper explores an extension of the Ishita distribution and introduces a new family of distributions based on this extension. The properties of the extended Ishita distribution are discussed, and parameter estimation is conducted using different methods. The extended Ishita distribution is applied to real data sets, and it is found to be more suitable for modeling the data compared to other distributions.
JOURNAL OF KING SAUD UNIVERSITY SCIENCE
(2022)
Article
Physics, Multidisciplinary
He Su, Chao-Yun Long
Summary: In this paper, the thermodynamic properties of the Schwarzschild and Reissner-Nordstrom black holes are investigated using the extended generalized uncertainty principle with linear terms (LEGUP). The minimal temperature, modified mass-temperature function, and heat capacity function of the Schwarzschild black hole are calculated. The thermodynamics of LEGUP black holes are compared with EGUP black holes and other forms, and the modification of black hole entropy is discussed.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2022)
Review
Energy & Fuels
Giovanni Mascali
Summary: This paper reviews the application of a new formula to calculate lattice thermal conductivity in silicon, germanium, and graphene. The formula is able to accurately reproduce the thermal conductivity of these materials, with phonon scattering mechanisms playing a significant role in determining their thermal transport properties.
Article
Astronomy & Astrophysics
Chatchai Promsiri, Ekapong Hirunsirisawat, Watchara Liewrian
Summary: Recent research using Renyi statistics has shown that asymptotically flat Schwarzschild black hole can achieve thermal equilibrium with an infinite heat reservoir under certain conditions, and a first-order Hawking-Page phase transition as a solid-liquid transition with latent heat of fusion has been identified. Furthermore, investigating the generalized second law of black hole thermodynamics in Renyi statistics by considering black hole as a working substance in a heat engine has revealed interesting results, such as the efficiency of the black hole in a Carnot cycle.
Article
Mathematics, Applied
Tommaso Ruggeri
Summary: This paper discusses a rarefied polyatomic gas with a non-polytropic equation of state and uses the maximum entropy principle (MEP) to obtain the closure of the binary hierarchy of 14 moments associated with the Boltzmann equation. The closed partial differential system is symmetric hyperbolic and well-posed for the Cauchy problem. In the limiting case of polytropic gas, it confirms previous results and completes the equivalence between different closure methods for non-polytropic gas.
RICERCHE DI MATEMATICA
(2021)
Article
Mathematics
Seung-Yeal Ha, Myeongju Kang, Hansol Park, Tommaso Ruggeri, Woojoo Shim
Summary: The study focuses on the emergent dynamics of the continuum thermodynamic Kuramoto model, showing two sequential processes of temperature homogenization and phase-locking. The phase field in a constant natural frequency field converges to one-point cluster or bipolar cluster, while in a nonconstant natural frequency field, it reaches a phased-locked state asymptotically.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Mathematics, Applied
M. C. Carrisi, S. Pennisi
Summary: This paper presents a model with 16 moments in the framework of relativistic non-equilibrium thermodynamics for polyatomic gases, extending previous work on both the non-relativistic case and the relativistic case with trace considerations.
RICERCHE DI MATEMATICA
(2021)
Article
Mathematics, Applied
Takashi Arima
Summary: This study explores the characteristic velocities of molecular rotational and vibrational relaxation processes in a van der Waals gas, estimating lower and upper bounds based on rarefied gases and the spinodal curve. Additionally, the dispersion relation of linear waves, including phase velocity, attenuation factor, and attenuation per wavelength in a low-frequency range, is investigated in detail.
RICERCHE DI MATEMATICA
(2021)
Article
Mechanics
Takashi Arima, Maria Cristina Carrisi, Sebastiano Pennisi, Tommaso Ruggeri
Summary: Inspired by Pennisi (2021) in the relativistic framework, this study proposes a new natural physical hierarchy of moments to describe classical rarefied non-polytropic polyatomic gas within the framework of Molecular Rational Extended Thermodynamics. By considering the case of 15 moments and utilizing the variational method of the Maximum Entropy Principle, the system is closed and the convexity of entropy is proven, with the possibility of putting the system in symmetric form. This richer kinetic framework may have potential applications in biomathematics and other fields where kinetic models have been successfully applied recently.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2021)
Article
Physics, Multidisciplinary
Takashi Arima, Maria Cristina Carrisi, Sebastiano Pennisi, Tommaso Ruggeri
Summary: A relativistic extension of thermodynamics for polyatomic gases is proposed, taking into account the total energy of the system and the internal mode energy of molecules. Moment equations associated with the Boltzmann-Chernikov equation are derived and a closed system of equations is obtained. The system satisfies the entropy principle, making it symmetric hyperbolic and well-posed. The ultra-relativistic and classical limits are also studied, and subsystems with 14 and 6 moments are derived.
Article
Mathematics
Seung-Yeal Ha, Myeongju Kang, Hansol Park, Tommaso Ruggeri, Woojoo Shim
Summary: The study focuses on the emergent dynamics of the continuum thermodynamic Kuramoto model, showing two sequential processes of temperature homogenization and phase-locking. The phase field in a constant natural frequency field converges to one-point cluster or bipolar cluster, while in a nonconstant natural frequency field, it reaches a phased-locked state asymptotically.
JOURNAL OF DIFFERENTIAL EQUATIONS
(2021)
Article
Mechanics
Tommaso Ruggeri, Shigeru Taniguchi
Summary: The shock structure in a binary mixture of polyatomic Eulerian gases with different degrees of freedom is studied using the multi-temperature model of rational extended thermodynamics. The possible sub-shocks are identified based on the change in the Mach number and equilibrium concentration. The regions for sub-shock formation are determined and the relationship between acceleration waves and sub-shocks is derived.
Article
Mechanics
Takashi Arima, Andrea Mentrelli, Tommaso Ruggeri
Summary: The paper aims to demonstrate that a general system of 14 balance laws for a compressible, possibly dense, gas, which satisfies the universal principles of Rational Extended Thermodynamics (RET), converges to the Navier-Stokes-Fourier equations in the first step of the Maxwellian iteration. Furthermore, in a theory not far from equilibrium, the study shows that the production terms of the hyperbolic system can be uniquely determined by assigning the heat conductivity, shear viscosity, and bulk viscosity. The obtained results are tested on the RET theories for rarefied monatomic and polyatomic gases.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2023)
Article
Physics, Multidisciplinary
Takashi Arima, Masaru Sugiyama
Summary: This study investigates the nonequilibrium flows of a rarefied polyatomic gas through a diverging nozzle under the effect of dynamic pressure. It is found that even in a diverging nozzle, choking phenomena can occur if the gas at the nozzle inlet is in a nonequilibrium state. Furthermore, the controllability of gas flows in a nozzle by manipulating the temperature of molecular internal modes such as molecular rotation and vibration is discussed.
Article
Mathematics, Applied
Tommaso Ruggeri, Shigeru Taniguchi
Summary: In this study, we continue to investigate the formation of sub-shocks in a binary mixture of gases, taking into account the dissipation caused by bulk viscosity in both constituents. Using a mixture of gases model proposed by T. Arima et al., we classify the regions based on concentration and Mach number to determine whether sub-shocks may exist inside the shock profiles of the constituents. Numerical calculations of the shock profiles for various gas mixtures show that the presence of dissipation leads to a more regularized shock profile and a reduction in the amplitude of sub-shocks compared to non-dissipative gases.
RICERCHE DI MATEMATICA
(2023)
Article
Mathematics, Applied
Takashi Arima, Masaru Sugiyama
Summary: Flows of rarefied polyatomic gas in a nozzle with simple geometry were numerically studied using the rational extended thermodynamics theory with six independent fields (RET6). The study focused on the effect of dynamic pressure (nonequilibrium part of the pressure) on nozzle gas flows. By comparing the flow profiles with those predicted by the Euler theory, the development of nonequilibrium state of gas along the flow was investigated. Qualitatively different flow profiles from those predicted by the Euler theory were observed under certain conditions. Choking phenomena were also observed based on RET6. These findings confirm the usefulness of RET6 theory in analyzing nozzle gas flows.
RICERCHE DI MATEMATICA
(2023)
Article
Physics, Fluids & Plasmas
Takashi Arima, Tommaso Ruggeri
Summary: This paper aims to construct a new hierarchy of molecular extended thermodynamics for classical rarefied polyatomic gases, incorporating internal degrees of freedom, by deducing a new hierarchy from the classical limit of relativistic theory of moments. The field equations for 15 moments of the distribution function are closed with the maximum entropy principle, showing convergence to the Kremer 14-moment system in the monatomic limit.
Article
Mathematics, Applied
Tommaso Ruggeri, Qinghua Xiao
Summary: The study investigated the Riemann problem of the relativistic Euler system for rarefied monatomic and diatomic gases, focusing on the classical and ultrarelativistic limits of the results and showing agreement with existing literature.
RICERCHE DI MATEMATICA
(2021)
Article
Mathematics, Applied
Tommaso Ruggeri
Summary: This paper discusses a rarefied polyatomic gas with a non-polytropic equation of state and uses the maximum entropy principle (MEP) to obtain the closure of the binary hierarchy of 14 moments associated with the Boltzmann equation. The closed partial differential system is symmetric hyperbolic and well-posed for the Cauchy problem. In the limiting case of polytropic gas, it confirms previous results and completes the equivalence between different closure methods for non-polytropic gas.
RICERCHE DI MATEMATICA
(2021)
Article
Physics, Multidisciplinary
G. Mustafa, S. K. Maurya, Saibal Ray, Faisal Javed
Summary: In this study, we investigate the geometry of wormholes in the framework of general relativity and explore how quantum wave dark matter affects the dynamical configuration of the shell surrounding the wormhole. By using specific shape functions and introducing quantum wave dark matter, we obtain reasonable wormhole solutions and observe its effects on the stability of the shell.
Article
Physics, Multidisciplinary
Pritha Dolai, Christian Maes
Summary: Calorimetry for equilibrium systems aims to determine the energy levels' occupation and distribution by measuring thermal response, while nonequilibrium versions provide additional information on the dynamical accessibility of these states. Using calculations on a driven exclusion process, it is confirmed that a fermionic nonequilibrium steady state with exact computation of specific heat can be achieved. The divergence at zero temperature occurs when the Fermi energy and the kinetic barrier for loading and emptying are approximately equal. Additionally, a stable low temperature regime of negative specific heat appears when the kinetic barrier is density-dependent, indicating an anti-correlation between the stationary occupation's temperature-dependence and excess heat.
Article
Physics, Multidisciplinary
F. F. Nascimento, V. B. Bezerra, J. M. Toledo
Summary: We obtained the metric of the Hayward black hole surrounded by a cloud of strings, and analyzed the effects of the string cloud on the regularity of the solution and the energy conditions. Various aspects such as horizons, geodesics, effective potential, and thermodynamics were investigated. We compared the obtained results with the literature corresponding to the Hayward black hole without a string cloud.
