English
Related papers

Related papers: Collisional statistics of the hard-sphere gas

200 papers

We formulate and test a hybrid fluid-Monte Carlo scheme for the treatment of elastic collisions in gases and plasmas. While our primary focus and demonstrations of applicability are for moderately collisional plasmas, as described by the…

Computational Physics · Physics 2015-06-12 L. F. Ricketson , M. S. Rosin , R. E. Caflisch , Andris M. Dimits

It was previously shown that the superdroplet algorithm for modeling the collision-coalescence process can faithfully represent mean droplet growth in turbulent clouds. But an open question is how accurately the superdroplet algorithm…

Atmospheric and Oceanic Physics · Physics 2022-07-05 Xiang-Yu Li , Bernhard Mehlig , Gunilla Svensson , Axel Brandenburg , Nils E. L. Haugen

We study the collision rates and velocities for point-particles of different sizes in turbulent flows. We construct fits for the collision rates at specified velocities (effectively a collisional velocity probability distribution) for…

Earth and Planetary Astrophysics · Physics 2015-06-15 Alexander Hubbard

We investigate velocity statistics of homogeneous inelastic gases using the Boltzmann equation. Employing an approximate uniform collision rate, we obtain analytic results valid in arbitrary dimension. In the freely evolving case, the…

Statistical Mechanics · Physics 2007-05-23 E. Ben-Naim , P. L. Krapivsky

We address the problem of the so-called ``granular gases'', i.e. gases of massive particles in rapid movement undergoing inelastic collisions. We introduce a class of models of driven granular gases for which the stationary state is the…

Statistical Mechanics · Physics 2009-10-31 A. Puglisi , V. Loreto , U. Marini Bettolo Marconi , A. Vulpiani

We introduce the model of inelastic hard spheres with random restitution coefficient $\alpha$, in order to account for the fact that, in a vertically shaken granular system interacting elastically with the vibrating boundary, the energy…

Soft Condensed Matter · Physics 2009-11-07 Alain Barrat , Emmanuel Trizac , Jean-Noel Fuchs

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

Consider a system of N identical hard spherical particles moving in a d-dimensional box and undergoing elastic, possibly multi-particle, collisions. We develop a new algorithm that recovers the pre-collision state from the post-collision…

Computational Physics · Physics 2013-06-13 Kalyan S. Perumalla , Vladimir A. Protopopescu

In this paper we complete the program initiated by the first and second authors and rigorously derive a Boltzmann-type equation that incorporates higher order collisions among gas particles. More precisely, starting from a finite…

Analysis of PDEs · Mathematics 2024-09-11 Ioakeim Ampatzoglou , Nataša Pavlović , William Warner

N-body simulations of collisionless collapse have offered important clues to the construction of realistic stellar dynamical models of elliptical galaxies. Such simulations confirm and quantify the qualitative expectation that rapid…

Astrophysics · Physics 2007-05-23 M. Trenti , G. Bertin

A dust grain in a plasma has a fluctuating electric charge, and past work concludes that spherical grains in a stationary, collisionless plasma have an essentially Gaussian charge probability distribution. This paper extends that work to…

Plasma Physics · Physics 2014-01-28 Drew M. Thomas , Michael Coppins

We show that two basic mechanical processes, the collision of particles and rolling motion of a sphere on a plane, are intimately related. According to our recent findings, the restitution coefficient for colliding spherical particles…

Materials Science · Physics 2009-11-07 Nikolai V. Brilliantov , Thorsten Poeschel

This paper uses dynamical invariants to describe the evolution of collisionless systems subject to time-dependent gravitational forces without resorting to maximum-entropy probabilities. We show that collisionless relaxation can be viewed…

Astrophysics of Galaxies · Physics 2015-06-03 Jorge Peñarrubia

We present a new, simple, fast algorithm to numerically evolve disks of inelastically colliding particles surrounding a central star. Our algorithm adds negligible computational cost to the fastest existing collisionless N-body codes, and…

Astrophysics · Physics 2008-11-26 Yoram Lithwick , Eugene Chiang

The paper presents a solution to the Boltzmann kinetic equation based on the construction of its discrete conservative model. Discrete analogue of the collision integral is presented as a contraction of a tensor, which is independent from…

Statistical Mechanics · Physics 2017-07-04 George Arabuli

Suppose that a point-like steady source at $x=0$ injects particles into a half-infinite line. The particles diffuse and die. At long times a non-equilibrium steady state sets in, and we assume that it involves many particles. If the…

Statistical Mechanics · Physics 2015-12-07 Baruch Meerson

Particle-in-cell methods with stochastic collision models are commonly used to simulate collisional plasma dynamics, with applications ranging from hypersonic flight to semiconductor manufacturing. Code verification of such methods is…

Computational Physics · Physics 2026-05-26 Brian A. Freno , William J. McDoniel , Christopher H. Moore , Neil R. Matula

In collisional fluids, a number of key processes rely on the frequency of binary collisions. Collisions seem necessary to generate a shock wave when two fluids collide fast enough, to fulfill the Rankine-Hugoniot relations, to establish an…

Plasma Physics · Physics 2019-02-20 Antoine Bret

In particle-based algorithms, the effect of binary collisions is commonly described in a statistical way, using Monte Carlo techniques. It is shown that, in the relativistic regime, stringent constraints should be considered on the sampling…

Plasma Physics · Physics 2009-11-13 F. Peano , M. Marti , L. O. Silva , G. Coppa

The aim of this paper is to analyze a class of random motions which models the motion of a particle on the real line with random velocity and subject to the action of the friction. The speed randomly changes when a Poissonian event occurs.…

Probability · Mathematics 2009-12-31 Alessandro De Gregorio