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Related papers: BGK model for rarefied gas in a bounded domain

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In this work, we first develop a unified Bhatnagar-Gross-Krook lattice Boltzmann (BGK-LB) model for the $d$($d\geq 1$)-dimensional linear hyperbolic equation (L-HE), where the natural moments and the D$d$Q$(2d^2+1)$ [($2d^2+1$) discrete…

Numerical Analysis · Mathematics 2024-10-18 Ying Chen , Zhenhua Chai , Baochang Shi

In this article we focus on kinetic equations for gas mixtures since in applications one often has to deal with mixtures instead of a single gas. In particular we consider an approximation of the Boltzmann equation, the…

Analysis of PDEs · Mathematics 2022-03-30 Marlies Pirner , Sandra Warnecke

The Bhatnagar-Gross-Krook (BGK) single-relaxation-time collision model for the Boltzmann equation serves as the foundation of the lattice BGK (LBGK) method developed in recent years. The description of the collision as a uniform relaxation…

Numerical Analysis · Mathematics 2021-10-04 Xiaowen Shan , Yangyang Shi , Xuhui Li

We consider the socalled Bathnagar-Gross-Krook (BGK) model, an approximation of the Boltzmann equation, describing the time evolution of a single momoatomic rarefied gas and satisfying the same two main properties (conservation properties…

Analysis of PDEs · Mathematics 2021-10-26 Marlies Pirner

High temperature gases, for instance in hypersonic reentry flows, show complex phenomena like excitation of rotational and vibrational energy modes, and even chemical reactions. For flows in the continuous regime, simulation codes use…

Computational Physics · Physics 2020-03-17 Céline Baranger , Yann Dauvois , Gentien Marois , Jordane Mathé , Julien Mathiaud , Luc Mieussens

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 propose a BGK model of the quantum Boltzmann equation for gas mixtures. We also provide a sufficient condition that guarantees the existence of equilibrium coefficients so that the model shares the same conservation laws and $H$-theorem…

Analysis of PDEs · Mathematics 2020-07-08 Gi-Chan Bae , Christian Klingenberg , Marlies Pirner , Seok-Bae Yun

The unified gas kinetic scheme (UGKS) was initially designed to address multiscale challenges in rarefied gas dynamics and then extended to radiative transfert theory, as described by BGK like relaxation models. In this work, we extend its…

Numerical Analysis · Mathematics 2025-07-08 Julien Mathiaud , Luc Mieussens , Nicolas Crouseilles

We consider a kinetic description of a multi-species gas mixture modeled with Bhatnagar-Gross-Krook (BGK) collision operators, in which the collision frequency varies not only in time and space but also with the microscopic velocity. In…

Numerical Analysis · Mathematics 2022-11-14 Jeffrey Haack , Cory Hauck , Christian Klingenberg , Marlies Pirner , Sandra Warnecke

Bhatnagar-Gross-Krook (BGK) collision kernel is employed in the Boltzmann equation to formulate relativistic dissipative hydrodynamics. In this formulation, we find that there remains freedom of choosing a matching condition that affects…

Nuclear Theory · Physics 2024-04-24 Pracheta Singha , Samapan Bhadury , Arghya Mukherjee , Amaresh Jaiswal

A non-perturbative analysis of the Bhatnagar-Gross-Krook (BGK) model kinetic equation for finite values of the Knudsen number is presented. This analysis indicates why discrete kinetic versions of the BGK equation, and notably the Lattice…

Statistical Mechanics · Physics 2009-11-11 Mauro Sbragaglia , Sauro Succi

Analytical solution of second Stokes problem of behaviour of rarefied gas with Cercignani boundary accomodation conditions The second Stokes problem about behaviour of rarefied gas filling half-space is analytically solved. A plane,…

Mathematical Physics · Physics 2015-06-05 A. V. Latyshev , A. A. Yushkanov

In this paper, we study the two dimensional lattice Boltzmann BGK model (LBGK) by analytically solving a simple flow in a 2~-D channel. The flow is driven by the movement of upper boundary with vertical injection fluid at the porous…

comp-gas · Physics 2016-08-31 Xiaoyi He , Qisu Zou

In this paper the global existence of weak solutions to the relativistic BGK model for the relativistic Boltzmann equation is analyzed. The proof relies on the strong compactness of the density, velocity and temperature under minimal…

Analysis of PDEs · Mathematics 2019-02-21 Juan Calvo , Pierre-Emmanuel Jabin , Juan Soler

In this paper, we consider the existence problem for a stationary relaxational models of the quantum Boltzmann equation. More precisely, we establish the existence of mild solution to the fermionic or bosonic quantum BGK model in a slab…

Analysis of PDEs · Mathematics 2020-01-29 Gi-Chan Bae , Seok-Bae Yun

We propose a BGK-type kinetic model for relativistic reactive gas mixtures. This model serves as a computationally tractable yet physically consistent alternative to the corresponding Boltzmann equation. The relaxation operator is…

Analysis of PDEs · Mathematics 2025-09-03 Seung-Yeon Cho , Byung-Hoon Hwang , Myeong-Su Lee , Seok-Bae Yun

We study a two phase flow with interactions of liquid and rarefied gas inside the gas phase. The gas phase is modeled by the BGK model of the Boltzmann equation. The liquid phase is modeled by the incompressible Navier-Stokes equations. In…

Fluid Dynamics · Physics 2022-04-06 S. Tiwari , A. Klar , G. Russo

We study the Boltzmann equation in a smooth bounded domain featuring a mixed boundary condition. Specifically, gas particles experience specular reflection in two parallel plates, while diffusive reflection occurs in the remaining portion…

Analysis of PDEs · Mathematics 2024-01-03 Hongxu Chen , Renjun Duan

We consider a kinetic model for a two component gas mixture without chemical reactions. Our goal is to study hypocoercivity for the linearized BGK model for gas mixtures in continuous phase space. By constructing an entropy functional, we…

Analysis of PDEs · Mathematics 2020-01-15 Liu Liu , Marlies Pirner

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