1999•arXiv (Cornell University)Open access

Comment II on J.M. Salazar and L. Brenig's article: ``Computer Simulations and Kinetic Theory of an Inelastic Granular Gas''

M. H. Ernst

Open full text 0 citations

Abstract

In two recent articles Salazar and Brenig question the validity of kinetic theory for granular gases and fluids, on the based of a supposedly exact hierarchy of coupled equations for the velocity moments, which the authors derive from the BBGKY-hierarchy. Their derivation contains several errors, which are exposed. Moreover, they support their findings with results from direct monte carlo simulation (DSMC) of the Boltzmann equation, which supposedly show that Haff's homogeneous cooling law only holds for times shorter than one mean free time. However, their DSMC results have no physical significance as they are carried out at a density, twice close packing.

Open-access reader

About this research paper

What this paper is about

In two recent articles Salazar and Brenig question the validity of kinetic theory for granular gases and fluids, on the based of a supposedly exact hierarchy of coupled equations for the velocity moments, which the authors derive from the BBGKY-hierarchy. Their derivation contains several errors, which are exposed. Moreover, they support their findings with results from direct monte carlo simulation (DSMC) of the Boltzmann equation, which supposedly show that Haff's homogeneous cooling law only holds for times shorter than one mean free time. However, their DSMC results have no physical significance as they are carried out at a density, twice close packing.

Why it matters

A significance statement is not available in the OpenAlex record.

Key contribution

A contribution statement is not available in the OpenAlex record.

Method / approach

Method details are not available in the OpenAlex metadata.

Main findings

Findings are not separately available in the OpenAlex metadata.

Limitations

Limitations are not available in the OpenAlex metadata.

Applications

Application details are not available in the OpenAlex metadata.

Available abstract

In two recent articles Salazar and Brenig question the validity of kinetic theory for granular gases and fluids, on the based of a supposedly exact hierarchy of coupled equations for the velocity moments, which the authors derive from the BBGKY-hierarchy. Their derivation contains several errors, which are exposed. Moreover, they support their findings with results from direct monte carlo simulation (DSMC) of the Boltzmann equation, which supposedly show that Haff's homogeneous cooling law only holds for times shorter than one mean free time. However, their DSMC results have no physical significance as they are carried out at a density, twice close packing.

Key concepts: BBGKY hierarchy, Kinetic theory, Hierarchy, Homogeneous, Boltzmann equation, Kinetic energy, Statistical physics, Boltzmann constant

Related papers

Back to paper searchBrowse research topicsOriginal source
Comment II on J.M. Salazar and L. Brenig's article: ``Computer Simulations and Kinetic Theory of an Inelastic Granular Gas'' — Research Paper | ScholarLens