English
Related papers

Related papers: The random gas of hard spheres

200 papers

The transport coefficients of a dilute gas of inelastic hard spheres immersed in a molecular gas are determined. We assume that the number density of the granular gas is much smaller than that of the surrounding molecular gas, so that the…

Soft Condensed Matter · Physics 2022-06-07 Rubén Gómez González , Vicente Garzó

We present a new hydrodynamic model consisting of the pressureless Euler equations and the isentropic compressible Navier-Stokes equations where the coupling of two systems is through the drag force. This coupled system can be derived, in…

Analysis of PDEs · Mathematics 2016-04-19 Young-Pil Choi , Bongsuk Kwon

We study a two-dimensional gas of inelastic smooth hard dimers. Since the collisions between dimers are dissipative, being characterized by a coefficient of restitution $\alpha<1$, and no external driving force is present, the energy of the…

It has been known since Lanford [19] that the dynamics of a hard sphere gas is described in the low density limit by the Boltzmann equation, at least for short times. The classical strategy of proof fails for longer times, even close to…

Analysis of PDEs · Mathematics 2020-12-08 Thierry Bodineau , Isabelle Gallagher , Laure Saint-Raymond , Sergio Simonella

A stochastic Euler equation is proposed, describing the motion of a particle density, forced by the random action of virtual photons in vacuum. After time averaging, the Euler equation is reduced to the Reynolds equation, well studied in…

Quantum Physics · Physics 2019-05-09 Roumen Tsekov , Eyal Heifetz , Eliahu Cohen

We consider the relativistic statistical mechanics of an ensemble of $N$ events with motion in space-time parametrized by an invariant ``historical time'' $\tau .$ We generalize the approach of Yang and Yao, based on the Wigner distribution…

High Energy Physics - Theory · Physics 2009-10-28 L. Burakovsky , L. P. Horwitz

Direct Monte Carlo simulations of the Enskog-Boltzmann equation for a spatially uniform system of smooth inelastic spheres are performed. In order to reach a steady state, the particles are assumed to be under the action of an external…

Statistical Mechanics · Physics 2016-08-31 J. M. Montanero , A. Santos

We develop the Cauchy theory of the spatially homogeneous inelastic Boltzmann equation for hard spheres, for a general form of collision rate which includes in particular variable restitution coefficients depending on the kinetic energy and…

Analysis of PDEs · Mathematics 2016-08-16 Stéphane Mischler , Clément Mouhot , Mariano Rodriguez Ricard

Within the class of nonlinear hyperbolic balance laws posed on a curved spacetime (endowed with a volume form), we identify a hyperbolic balance law that enjoys the same Lorentz invariance property as the one satisfied by the Euler…

Analysis of PDEs · Mathematics 2012-08-08 Philippe G. LeFloch , Hasan Makhlof , Baver Okutmustur

In this paper, we derive first-order Euler finite element discretization schemes for a time-dependent natural convection model with variable density (NCVD). The model is governed by the variable density Navier-Stokes equations coupled with…

Numerical Analysis · Mathematics 2025-05-20 Li Hang , Chenyang Li

In this paper, we present the algorithm for the simulation of a single bubble rising in a stagnant liquid using Euler-Lagrangian (EL) approach. The continuous liquid phase is modeled using BGK approximation of lattice Boltzmann method…

Fluid Dynamics · Physics 2017-10-24 Alankar Agarwal , B. Ravindra , Akshay Prakash

A recently introduced family of lattice Boltzmann (LB) models (Karlin, B\"osch, Chikatamarla, Phys. Rev. E, 2014) is studied in detail for incompressible two-dimensional flows. A framework for developing LB models based on entropy…

Fluid Dynamics · Physics 2015-07-10 Fabian Bösch , Shyam S. Chikatamarla , Ilya Karlin

The simulation of complex stochastic network dynamics arising, for instance, from models of coupled biomolecular processes remains computationally challenging. Often, the necessity to scan a models' dynamics over a large parameter space…

Quantitative Methods · Quantitative Biology 2013-03-14 Tiago Ramalho , Marco Selig , Ulrich Gerland , Torsten A. Enßlin

We compare the steady state velocity distributions from our three-dimensional inelastic hard sphere molecular dynamics simulation for homogeneously heated granular media, with the predictions of a mean field-type Enskog-Boltzmann equation…

Soft Condensed Matter · Physics 2009-11-07 Sung Joon Moon , M. D. Shattuck , J. B. Swift

The description of a stellar system as a continuous fluid represents a convenient first approximation to stellar dynamics, and its derivation from the kinetic theory is standard. The challenge lies in providing adequate closure…

Astrophysics · Physics 2007-05-23 Edward A. Spiegel , Jean-Luc Thiffeault

Neither molecular kinetics nor continuum fluid dynamics alone is adequate to describe multiscale gas flows across different regimes. Bridging these regimes within a single self-consistent framework has long been a central challenge in fluid…

Fluid Dynamics · Physics 2026-02-24 Zhaoli Guo , Kun Xu , Yajun Zhu

The collective dynamics of liquid Gallium close to the melting point has been studied using Inelastic X-ray Scattering to probe lengthscales smaller than the size of the first coordination shell. %(momentum transfers, $Q$, $>$15 nm$^{-1}$).…

Disordered Systems and Neural Networks · Physics 2009-11-11 T. Scopigno , R. Di Leonardo , L. Comez , A. Q. R. Baron , D. Fioretto , G. Ruocco

The kinetic theory description of a low density gas of hard spheres or disks, confined between two parallel plates separated a distance smaller than twice the diameter of the particles, is addressed starting from the Liouville equation of…

Statistical Mechanics · Physics 2024-09-06 J. Javier Brey , M. I. García de Soria , P. Maynar

The Boltzmann kinetic equation is obtained from an integro-differential master equation that describes a stochastic dynamics in phase space of an isolated thermodynamic system. The stochastic evolution yields a generation of entropy,…

Statistical Mechanics · Physics 2019-06-05 Mário J. de Oliveira

We investigate generalized Navier-Stokes (GNS) equations that couple nonlinear advection with a generic linear instability. This analytically tractable minimal model for fluid flows driven by internal active stresses has recently been shown…

Fluid Dynamics · Physics 2020-04-10 Rohit Supekar , Vili Heinonen , Keaton J. Burns , Jörn Dunkel