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Related papers: Thermal collapse of a granular gas under gravity

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The global energy fluctuations of a low density gas granular gas in the homogeneous cooling state near its clustering instability are studied by means of molecular dynamics simulations. The relative dispersion of the fluctuations is shown…

Statistical Mechanics · Physics 2009-11-10 J. Javier Brey , M. I. Garcia de Soria , P. Maynar , M. J. Ruiz-Montero

Using diamagnetically levitated particles we investigate the dynamics of the freely cooling granular gas. At early times we find good agreement with Haff's law, where the time scale for particle collisions can be determined from independent…

Statistical Mechanics · Physics 2009-11-13 C. C. Maaß , N. Isert , G. Maret , C. M. Aegerter

We develop a formulation of global thermodynamics for equilibrium systems under the influence of gravity. The free energy for simple fluids is extended to include a dependence on $(T, V, N, mgL)$, where $L$ represents the vertical system…

Statistical Mechanics · Physics 2025-06-26 Naoko Nakagawa , Shin-ichi Sasa , Takamichi Hirao , Tsuyoshi Shiina , Kyosuke Tachi , Akira Yoshida

We investigate the granular temperatures in force-free granular gases under exponential resetting. When a resetting event occurs, the granular temperature attains its initial value, whereas it decreases because of the inelastic collisions…

Soft Condensed Matter · Physics 2024-12-17 Anna S. Bodrova , Aleksei V. Chechkin , Awadhesh Kumar Dubey

Spurred by rich, multi-wavelength observations and enabled by new simulations, ranging from cosmological to sub-pc scales, the last decade has seen major theoretical progress in our understanding of the circumgalactic medium. We review key…

Astrophysics of Galaxies · Physics 2023-01-26 Claude-Andre Faucher-Giguere , S. Peng Oh

In contrast to molecular gases, granular gases are characterized by inelastic collisions and require therefore permanent driving to maintain a constant kinetic energy. The kinetic theory of granular gases describes how the average velocity…

Soft Condensed Matter · Physics 2020-05-25 Peidong Yu , Matthias Schröter , Matthias Sperl

We perform global linear stability analysis and idealized numerical simulations in global thermal balance to understand the condensation of cold gas from hot/virial atmospheres (coronae), in particular the intracluster medium (ICM). We pay…

Astrophysics of Galaxies · Physics 2016-02-15 Prakriti Pal Choudhury , Prateek Sharma

Stars form by the gravitational collapse of interstellar gas. The thermodynamic response of the gas can be characterized by an effective equation of state. It determines how gas heats up or cools as it gets compressed, and hence plays a key…

We study in this work the dynamics of a granular impurity immersed in a low-density granular gas of identical particles. For description of the kinetics of the granular gas and the impurity particles we use the rough hard sphere collisional…

Soft Condensed Matter · Physics 2017-07-13 Francisco Vega Reyes , Antonio Lasanta , Andrés Santos , Vicente Garzó

A gas of particles which collide inelastically if their impact velocity exceeds a certain value is investigated. In difference to common granular gases, cluster formation occurs only as a transient phenomenon. We calculate the decay of…

Statistical Mechanics · Physics 2009-11-07 Thorsten Poeschel , Nikolai V. Brilliantov , Thomas Schwager

We examine the dynamics of a self--gravitating magnetized electron gas at finite temperature near the collapsing singularity of a Bianchi-I spacetime. Considering a general and appropriate and physically motivated initial conditions, we…

General Relativity and Quantum Cosmology · Physics 2015-06-15 I. Delgado Gaspar , A. Perez Martinez , Roberto A. Sussman , A. Ulacia Rey

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 investigate freely cooling systems of rough spheres in two and three dimensions. Simulations using an event driven algorithm are compared with results of an approximate kinetic theory, based on the assumption of a generalized homogeneous…

Statistical Mechanics · Physics 2009-10-31 S. Luding , M. Huthmann , S. McNamara , A. Zippelius

Freezing and melting of large three-dimensional complex plasmas under microgravity conditions is investigated. The neutral gas pressure is used as a control parameter to trigger the phase changes: Complex plasma freezes (melts) by…

One of the questions in the cosmology courses is the cooling mechanism of cosmic fluid during it expansion according to classical concepts of the thermodynamics. In this short pedagogical paper, we quote the questions and give a natural…

Physics Education · Physics 2007-05-23 Sohrab Rahvar

We have developed a kinetic theory of hard needles undergoing binary collisions with loss of energy due to normal and tangential restitution. In addition, we have simulated many particle systems of granular hard needles. The theory, based…

Statistical Mechanics · Physics 2009-10-31 Martin Huthmann , Timo Aspelmeier , Annette Zippelius

We employ hydrodynamic equations to follow the clustering instability of a freely cooling dilute gas of inelastically colliding spheres into a well-developed nonlinear regime. We simplify the problem by dealing with a one-dimensional…

Statistical Mechanics · Physics 2009-11-10 Efi Efrati , Eli Livne , Baruch Meerson

We study, via hydrodynamic equations, the granular temperature profile of a granular fluid under gravity and subjected to energy injection from a base. It is found that there exists a turn-up in the granular temperature and that, far from…

Statistical Mechanics · Physics 2016-08-31 Rosa Ramirez , Rodrigo Soto

Structure in the Universe grew through gravitational instability from very smooth initial conditions. Energy conservation requires that the growing negative potential energy of these structures is balanced by an increase in kinetic energy.…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-17 Adam Moss , Douglas Scott

In this paper we investigate, both analytically and numerically, the emergence of a kinetic glass transition in two different model systems: a uniformly heated granular gas and a molecular fluid with nonlinear drag. Despite the profound…

Soft Condensed Matter · Physics 2024-04-25 A. Patrón , B. Sánchez-Rey , A. Prados