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Related papers: Towards an $H$-theorem for granular gases

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Thermal fluctuations of the granular gas under the homogeneous cooling state (HCS) are estimated using two-point kinetic theory by Tsuge-Sagara. Thermal fluctuations of the elastic gas are modified for the granular gas by nonequilibrium…

Fluid Dynamics · Physics 2011-02-22 Ryosuke Yano , Kojiro Suzuki

A new microscopic formula for the viscosity of liquids and solids is derived rigorously from a first-principles (microscopically reversible) Hamiltonian for particle-bath atomistic motion. The derivation is done within the framework of…

Soft Condensed Matter · Physics 2024-04-17 Alessio Zaccone

We consider the characterization of the nonequilibrium stationary state of a randomly-driven granular gas in terms of an entropy-production based variational formulation. Enforcing spatial homogeneity, we first consider the temporal…

Statistical Mechanics · Physics 2007-05-23 Ioana Bena , Francois Coppex , Michel Droz , Paolo Visco , Emmanuel Trizac , Frederic van Wijland

Granular systems confined in a shallow box and driven by vertical vibration provide a simple geometry to study fluidized granular media. Grains gain kinetic energy vertically through collisions with the walls and redistribute it…

Soft Condensed Matter · Physics 2026-04-21 Ricardo Brito , Rodrigo Soto , Vicente Garzó

A basic aspect of the kinetic descriptions of incompressible fluids based on an inverse kinetic approaches is the possibility of satisfying an H-theorem. This property is in fact related to the identification of the kinetic distribution…

Fluid Dynamics · Physics 2007-05-23 M. Tessarotto , M. Ellero

We formulate a dynamical fluctuation theory for stationary non equilibrium states (SNS) which is tested explicitly in stochastic models of interacting particles. In our theory a crucial role is played by the time reversed dynamics. Within…

Statistical Mechanics · Physics 2015-12-18 L. Bertini , A. De Sole , D. Gabrielli , G. Jona-Lasinio , C. Landim

Recently linear dissipative models of the Boltzmann equation have been introduced. In this work, we consider the problem of constructiing suitable hydrodynamic approximations for such models where the mean velocity and the temperature of…

Analysis of PDEs · Mathematics 2007-05-23 Stephane Brull , Lorenzo Pareschi

A kinetic approach is adopted to describe the exponential growth of a small deviation of the initial phase space point, measured by the largest Lyapunov exponent, for a dilute system of hard disks, both in equilibrium and in a uniform shear…

Chaotic Dynamics · Physics 2015-06-26 R. van Zon , H. van Beijeren

This paper presents a molecular dynamics simulation of an inelastic gas, where collisions between molecules are characterized by a coefficient of restitution less than unity. The simulation employs an event-driven algorithm to efficiently…

Computational Physics · Physics 2025-02-03 Rameez Farooq Shah , Shikha Kumari , Syed Rashid Ahmad

The non-Newtonian character of granular flow in a vertical pipe is analyzed. The time evolution of the flow velocity and the velocity fluctuations (or granular temperature) is derived. The steady state velocity has a power law dependence on…

Statistical Mechanics · Physics 2009-10-31 D. E. Wolf , T. Scheffler , J. Schäfer

The empirical observation of aggregation of dielectric particles under the influence of electrostatic forces lies at the origin of the theory of electricity. The growth of clusters formed of small grains underpins a range of phenomena from…

Soft Condensed Matter · Physics 2019-07-01 Chamkor Singh , Marco G. Mazza

A simplified relativistic kinetic theory for gases with internal degrees of freedom, based on a BGK-type collision term, is considered. First the Boltzmann equation is rewritten in tetrad form and then thermal coefficients are determined to…

General Relativity and Quantum Cosmology · Physics 2026-04-13 Philip Semrén , Michael Bradley , João M. S. Oliveira , M. Piedade Machado Ramos

The flow characterized by a linear longitudinal velocity field $u_x(x,t)=a(t)x$, where $a(t)={a_0}/({1+a_0t})$, a uniform density $n(t)\propto a(t)$, and a uniform temperature $T(t)$ is analyzed for dilute granular gases by means of a…

Soft Condensed Matter · Physics 2014-11-10 Andres Santos

A granular gas subjected to a permanent injection of energy is described by means of hydrodynamic equations derived from a moment expansion method. The method uses as reference function not a Maxwellian distribution $f_{\sf M}$ but a…

Statistical Mechanics · Physics 2009-10-31 Rosa Ramirez , Dino Risso , Rodrigo Soto , Patricio Cordero

We consider a non-interacting one-dimensional gas accelerated by a constant and uniform external field. The energy absorbed from the field is transferred via elastic collisions to a bath of scattering obstacles. At gas-obstacle encounters…

Statistical Mechanics · Physics 2009-11-11 Jaroslaw Piasecki , Rodrigo Soto

The theory of homogeneously driven granular gases of hard particles predicts that the stationary state is characterized by a velocity distribution function with overpopulated high-energy tails as compared to the exponential decay valid for…

Soft Condensed Matter · Physics 2017-10-10 Christian Scholz , Thorsten Pöschel

Granular gaseous mixtures under rapid flow conditions are usually modeled by a multicomponent system of smooth inelastic hard spheres with constant coefficients of normal restitution. In the low density regime an adequate framework is…

Statistical Mechanics · Physics 2009-11-13 Francisco Vega Reyes , Vicente Garzo , Andres Santos

Boltzmann's H-Theorem, formulated 150 years ago in terms of H-function that also bears his name, is one of the most celebrated theorems of science and paved the way for the development of nonequilibrium statistical mechanics. Nevertheless,…

Statistical Mechanics · Physics 2022-07-05 Shubham Kumar , Subhajit Acharya , Biman Bagchi

We present a new numerical algorithm based on a relative energy scaling for collisional kinetic equations allowing to study numerically their long time behavior, without the usual problems related to the change of scales in velocity…

Analysis of PDEs · Mathematics 2015-06-04 Francis Filbet , Thomas Rey

A linear stability analysis of the hydrodynamic equations of a model for confined quasi-two-dimensional granular gases is carried out. The stability analysis is performed around the homogeneous steady state (HSS) reached eventually by the…

Statistical Mechanics · Physics 2021-06-10 Vicente Garzó , Ricardo Brito , Rodrigo Soto