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Related papers: The random gas of hard spheres

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The continuous injection of energy in a stationary gas creates a shock wave that propagates radially outwards. We study the hydrodynamics of this disturbance using event driven molecular dynamics of a hard sphere gas in two and three…

Statistical Mechanics · Physics 2025-04-07 Amit Kumar , R. Rajesh

We investigate in this article the long-time behaviour of the solutions to the energy-dependant, spatially-homogeneous, inelastic Boltzmann equation for hard spheres. This model describes a diluted gas composed of hard spheres under…

Analysis of PDEs · Mathematics 2012-07-18 Thomas Rey

We calculate in this work the Navier-Stokes transport coefficients from the Boltzmann equation for $d$-dimensional inelastic Maxwell models. By granular gas we mean here a low density system of identical spheres that lose a fraction of…

Statistical Mechanics · Physics 2015-06-18 Moisés G. Chamorro , Vicente Garzó , Francisco Vega Reyes

We present a mathematical theory of dynamical fluctuations for the hard sphere gas in the Boltzmann-Grad limit. We prove that: (1) fluctuations of the empirical measure from the solution of the Boltzmann equation, scaled with the square…

Analysis of PDEs · Mathematics 2022-08-26 Thierry Bodineau , Isabelle Gallagher , Laure Saint-Raymond , Sergio Simonella

In this paper we presented an overview on our works. More than ten years ago, we proposed a new fundamental equation of nonequilibrium statistical physics in place of the present Liouville equation. That is the stochastic velocity type's…

Statistical Mechanics · Physics 2019-08-19 Xiu-San Xing

A simple exactly solvable kinetic model for the non-linear inelastic hard sphere Boltzmann equation is used to explore the relevance of hydrodynamics for a granular gas. The equation predicts a non-trivial homogeneous cooling state (HCS),…

Soft Condensed Matter · Physics 2007-05-23 Aparna Baskaran , James W. Dufty

The effects of volume exclusion and long-range intermolecular attraction are investigated by the simplified kinetic model for surface-confined inhomogeneous fluids. Gas dynamics of the ideal gas, the hard-sphere fluid and the real gas are…

Fluid Dynamics · Physics 2020-05-20 Baochao Shan , Peng Wang , Songze Chen , Zhaoli Guo

The lattice Boltzmann method has become a standard for efficiently solving problems in fluid dynamics. While unstructured grids allow for a more efficient geometrical representation of complex boundaries, the lattice Boltzmann methods is…

Modeling dispersed solid phases in fluids still represents a computational challenge when considering a small-scale coupling in wide systems, such as the atmosphere or industrial processes at high Reynolds numbers. A numerical method is…

Fluid Dynamics · Physics 2015-08-13 François Laenen , Giorgio Krstulovic , Jérémie Bec

For the water-air system, the bulk density ratio is as high as about 1000; no model can fully tackle such a high density ratio system. In the Navier-Stokes and Euler equations, the density $\rho$ within the water-air interface is assumed to…

Fluid Dynamics · Physics 2026-01-27 Fei Wang

Consider a microscopic system of $N$ hard spheres that are initially independent (modulo the exclusion condition on particle positions) and identically distributed in $\mathbb{R}^3$. When the number $N$ of particles goes to infinity and the…

Analysis of PDEs · Mathematics 2026-02-05 Thierry Bodineau , Isabelle Gallagher , Laure Saint-Raymond , Sergio Simonella

The Boltzmann equation becomes invalid as the size of gas molecules is comparable with the average intermolecular distance. A better description is provided by the Enskog collision operator, which takes into account the finite size of gas…

Fluid Dynamics · Physics 2023-01-25 S. Busuioc

We present a quantitative analysis of the inertial range statistics produced by Entropic Lattice Boltzmann Method (ELBM) in the context of 3d homogeneous and isotropic turbulence. ELBM is a promising mesoscopic model particularly…

Fluid Dynamics · Physics 2021-07-14 Michele Buzzicotti , Guillaume Tauzin

A kinetic equation for a dilute gas of hard spheres confined between two parallel plates separated a distance smaller than two particle dimeters is derived. It is a Boltzmann-like equation, which incorporates the effect of the confinement…

Statistical Mechanics · Physics 2016-11-23 J. Javier Brey , P. Maynar , M. I. García de Soria

The dynamics of inelastic hard spheres is described in terms of the binary collision expansion, yielding the corresponding pseudo-Liouville equation and BBGKY hierarchy for the reduced distribution functions. Based on cluster expansion…

Statistical Mechanics · Physics 2008-02-03 T. P. C. van Noije , M. H. Ernst

Starting from the fluctuating Boltzmann equation for smooth inelastic hard spheres or disks, closed equations for the fluctuating hydrodynamic fields to Navier-Stokes order are derived. This requires to derive constitutive relations for…

Statistical Mechanics · Physics 2015-05-27 J. Javier Brey , P. Maynar , M. I. Garcia de Soria

We will revisit the classical questions of understanding the statistics of various deterministic dynamics of $N$ hard spheres of diameter $\varepsilon$ with random initial data in the Boltzmann-Grad scaling as $\varepsilon$ tends to zero…

Analysis of PDEs · Mathematics 2024-05-08 Karsten Matthies , Theodora Syntaka

Various lattice gas automata have been proposed in the past decades to simulate physics and address a host of problems on collective dynamics arising in diverse fields. In this work, we employ the lattice gas model defined on the sphere to…

Statistical Mechanics · Physics 2017-12-29 Zhenwei Yao

Molecular dynamics simulations are carried out to investigate the diffusion behavior of penetrable-sphere model fluids characterized by a finite energy barrier $\epsilon$. The self-diffusion coefficient is evaluated from the time-dependent…

Soft Condensed Matter · Physics 2010-11-22 Soong-Hyuck Suh , Chun-Ho Kim , Soon-Chul Kim , Andrés Santos

We conduct a numerical study of the dynamic behavior of a dense hard sphere fluid by deriving and integrating a set of Langevin equations. The statics of the system is described by a free energy functional of the Ramakrishnan-Yussouff form.…

Condensed Matter · Physics 2009-10-22 Lisa M. Lust , Oriol T. Valls , Chandan Dasgupta