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Related papers: A BGK model for high temperature rarefied gas flow…

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We analyze a large number of high-order discrete velocity models for solving the Boltzmann-BGK equation for finite Knudsen number flows. Using the Chapman-Enskog formalism, we prove for isothermal flows a relation identifying the resolved…

Fluid Dynamics · Physics 2016-08-03 C. Feuchter , W. Schleifenbaum

Granular gaseous mixtures under rapid flow conditions are usually modeled by a multicomponent system of smooth inelastic hard spheres with constant coefficients of normal restitution. In the low density regime an adequate framework is…

Statistical Mechanics · Physics 2009-11-13 Francisco Vega Reyes , Vicente Garzo , Andres Santos

We have computed the charge and heat transport coefficients of hot QCD matter by solving the relativistic Boltzmann transport equation using the BGK model approximation with a modified collision integral in the weak magnetic field regime.…

High Energy Physics - Phenomenology · Physics 2022-10-28 Anowar Shaikh , Shubhalaxmi Rath , Sadhana Dash , Binata Panda

A simplified relativistic kinetic theory for gases with internal degrees of freedom, based on a BGK-type collision term, is considered. First the Boltzmann equation is rewritten in tetrad form and then thermal coefficients are determined to…

General Relativity and Quantum Cosmology · Physics 2026-04-13 Philip Semrén , Michael Bradley , João M. S. Oliveira , M. Piedade Machado Ramos

In this work, we have theoretically analyzed and numerically evaluated the accuracy of high-order lattice Boltzmann (LB) models for capturing non-equilibrium effects in rarefied gas flows. In the incompressible limit, the LB equation is…

Fluid Dynamics · Physics 2009-09-08 Jianping Meng , Yonghao Zhang

Convection is a ubiquitous process driving geophysical/astrophysical fluid flows, which are typically strongly constrained by planetary rotation on large scales. A celebrated model of such flows, rapidly rotating Rayleigh-B\'enard…

Fluid Dynamics · Physics 2025-06-24 Keith Julien , Adrian van Kan , Benjamin Miquel , Edgar Knobloch , Geoffrey Vasil

Kinetic models of polyatomic gas typically account for the internal degrees of freedom at the level of the two-particle distribution function. However, close to the hydrodynamic limit, the internal (rotational) degrees of freedom tend to be…

Fluid Dynamics · Physics 2023-05-24 Praveen Kumar Kolluru , Mohammad Atif , Santosh Ansumali

This paper presents second-order accurate genuine BGK (Bhatnagar-Gross-Krook) schemes in the framework of finite volume method for the ultra-relativistic flows. Different from the existing kinetic flux-vector splitting (KFVS) or BGK-type…

Numerical Analysis · Mathematics 2017-09-13 Yaping Chen , Yangyu Kuang , Huazhong Tang

Rooted from the gas kinetics, the lattice Boltzmann method is a powerful tool in modeling hydrodynamics. In the past decade, it has been extended to simulate the rarefied gas flow beyond the Navier-Stokes level, either by using the…

Fluid Dynamics · Physics 2017-08-30 Scott Lindsay , Wei Su , Haihu Liu , Lei Wu

The Navier-Stokes transport coefficients of a granular gas are obtained from the Chapman-Enskog solution to the Boltzmann equation. The granular gas is heated by the action of an external driving force (thermostat) which does work to…

Statistical Mechanics · Physics 2009-11-07 V. Garzo , J. M. Montanero

The Boltzmann equation describes the detailed microscopic behaviour of a dilute gas, and represents the basis of the kinetic theory of gases. In order to reduce the difficulties in solving the Boltzmann equation, simple expressions of a…

Mathematical Physics · Physics 2018-12-06 Armando Majorana

We investigate numerically a recent BGK-type model for a multi-component mixture of monatomic gases, undergoing a reversible bimolecular chemical reaction. The model replaces each collisional term of the Boltzmann equation with a relaxation…

Statistical Mechanics · Physics 2026-02-23 Giorgio Martalò , Ana Jacinta Soares , Romina Travaglini

This paper reports an application of gas-kinetic BGK scheme to the computation of turbulent compressible convection in the stellar interior. After incorporating the Sub-grid Scale (SGS) turbulence model into the BGK scheme, we tested the…

Astrophysics · Physics 2016-03-07 Chun-Lin Tian , Li-Cai Deng , Kwing-Lam Chan , Da-Run Xiong

The multidimensional gas-kinetic scheme for the Navier-Stokes equations under gravitational fields [J. Comput. Phys. 226 (2007) 2003-2027] is extended to resistive magnetic flows. The non-magnetic part of the magnetohydrodynamics equations…

Instrumentation and Methods for Astrophysics · Physics 2010-10-19 Chun-Lin Tian

Ellipsoidal BGK model (ES-BGK) is a generalized version of the BGK model where the local Maxwellian in the relaxation operator of the BGK model is extended to an ellipsoidal Gaussian with a Prandtl parameter $\nu$, so that the correct…

Analysis of PDEs · Mathematics 2020-12-16 Stephane Brull , Seok-Bae Yun

In this paper, we propose a Runge-Kutta (RK) central discontinuous Galerkin (CDG) gas-kinetic BGK method for the Navier-Stokes equations. The proposed method is based on the CDG method defined on two sets of overlapping meshes to avoid…

Numerical Analysis · Mathematics 2015-06-18 Tan Ren , Jun Hu , Tao Xiong , Jing-Mei Qiu

The Enskog kinetic theory for moderately dense granular suspensions is considered as a model to determine the Navier-Stokes transport coefficients. The influence of the interstitial gas on solid particles is modeled by a viscous drag force…

Statistical Mechanics · Physics 2019-09-09 Rubén Gómez González , Vicente Garzó

The problem of wave disturbance propagation in rarefied gas in gravity field is explored. The system of hydrodynamic-type equations for a stratified gas in gravity field is derived from BGK equation by method of piecewise continuous…

Fluid Dynamics · Physics 2009-11-10 D. A. Vereshchagin , S. B. Leble , M. A. Solovchuk

We derive a multi-species BGK model with velocity-dependent collision frequency for a non-reactive, multi-component gas mixture. The model is derived by minimizing a weighted entropy under the constraint that the number of particles of each…

Analysis of PDEs · Mathematics 2021-09-29 Jeff Haack , Cory Hauck , Christian Klingenberg , Marlies Pirner , Sandra Warnecke

A kinetic model called the $\nu$-model is proposed to replace the complicated Boltzmann collision operator in the simulation of rarefied flows of monatomic gas. The model follows the relaxation-time approximation, but the collision…

Computational Physics · Physics 2022-01-26 Yuan RuiFeng , Wu Lei