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Related papers: Ellipsoidal BGK model near a global Maxwellian

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We establish global existence of mild solutions to the BGK model proposed by Bouchut [J. Stat. Phys., 95, (1999), 113--170] under the minimal assumption of finite kinetic entropy initial data. Moreover we rigorously derive a kinetic entropy…

Analysis of PDEs · Mathematics 2025-08-07 Dowan Koo , Sihyun Song

A recently introduced family of lattice Boltzmann (LB) models (Karlin, B\"osch, Chikatamarla, Phys. Rev. E, 2014) is studied in detail for incompressible two-dimensional flows. A framework for developing LB models based on entropy…

Fluid Dynamics · Physics 2015-07-10 Fabian Bösch , Shyam S. Chikatamarla , Ilya Karlin

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

Bhatnagar-Gross-Krook (BGK) equation is a relaxation model of the Boltzmann equation which is widely used in place of the Boltzmann equation for the simulation of various kinetic flow problems. In this work, we study the asymptotic…

Analysis of PDEs · Mathematics 2023-01-26 Gi-Chan Bae , Gyounghun Ko , Donghyun Lee , Seok-Bae Yun

In this paper, we establish the existence of the unique global-in-time classical solutions to the multi-component BGK model suggested in \cite{mixmodel} when the initial data is a small perturbation of global equilibrium. For this, we…

Analysis of PDEs · Mathematics 2022-01-06 Gi-Chan Bae , Christian Klingenberg , Marlies Pirner , Seok-Bae Yun

We present a hybrid Boltzmann-BGK model for inert mixtures, where each kind of binary interaction may be described by a classical Boltzmann integral or by a suitable relaxation-type operator. We allow also the possibility of changing the…

Mathematical Physics · Physics 2025-05-27 Marzia Bisi , Maria Groppi , Giorgio Martalò

It has recently been demonstrated that dynamical low-rank algorithms can provide robust and efficient approximation to a range of kinetic equations. This is true especially if the solution is close to some asymptotic limit where it is known…

Numerical Analysis · Mathematics 2021-05-13 Lukas Einkemmer , Jingwei Hu , Lexing Ying

The hydrodynamic limit for the Boltzmann equation is studied in the case when the limit system, that is, the system of Euler equations contains contact discontinuities. When suitable initial data is chosen to avoid the initial layer, we…

Analysis of PDEs · Mathematics 2015-05-13 Feimin Huang , Yi Wang , Tong Yang

The Bhatnagar-Gross-Krook (BGK) model, a simplification of the Boltzmann equation, in the absence of boundary effect, converges to the Euler equations when the Knudsen number is small. In practice, however, Knudsen layers emerge at the…

Numerical Analysis · Mathematics 2019-10-02 Hongxu Chen , Qin Li , Jianfeng Lu

We study the Bathnagar-Gross-Krook (BGK) equation in a smooth bounded domain featuring a diffusive reflection boundary condition with general collision frequency. We prove that the BGK equation admits a unique global solution with an…

Analysis of PDEs · Mathematics 2026-01-09 Hongxu Chen , Christian Klingenberg , Marlies Pirner

The generalization of the BGK relaxation model to the special relativity setting is revisited here. We deal with several issues related to this relativistic kinetic model which seem to have been overlooked in the previous physical…

Mathematical Physics · Physics 2013-07-12 Abdel Bellouquid , Juan Calvo , Juanjo Nieto , Juan Soler

This paper shows that, in the formal level, the convergence of solutions of Boltzmann equation to solutions of the compressible Navier-Stokes system with small Mach number over the three-dimensional periodic domain $\mathbb{T}^3$, using the…

Analysis of PDEs · Mathematics 2026-02-10 Yuhan Chen , Ning Jiang

We consider the neural representation to solve the Boltzmann-BGK equation, especially focusing on the application in microscopic flow problems. A new dimension reduction model of the BGK equation with the flexible auxiliary distribution…

Numerical Analysis · Mathematics 2024-10-30 Pei Zhang , Yanli Wang

It is well known that the full compressible Navier-Stokes equations can be deduced via the Chapman-Enskog expansion from the Boltzmann equation as the first-order correction to the Euler equations with viscosity and heat-conductivity…

Analysis of PDEs · Mathematics 2020-08-21 Renjun Duan , Shuangqian Liu

Two discretizations of a 9-velocity Boltzmann equation with a BGK collision operator are studied. A Chapman-Enskog expansion of the PDE system predicts that the macroscopic behavior corresponds to the incompressible Navier-Stokes equations…

comp-gas · Physics 2008-02-03 Marc B. Reider , James D. Sterling

The Bhatnagar-Gross-Krook (BGK) Boltzmann equation with the Maxwellian-Boltzmann-type equilibrium state leads to the set of thermo-hydrodynamic equations such as the continuity, the Navier-Stokes, and the heat-transfer equations in the…

Fluid Dynamics · Physics 2023-07-05 Hiroshi Otomo

I calculate the hydrodynamic limit of the BGK approximation of the Boltzmann equation for the case of a long stress relaxation time and find that the stress obeys a viscoelastic constitutive equation. The constitutive equation is different…

Statistical Mechanics · Physics 2007-05-23 Alexander J. Wagner

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

Lattice Boltzmann simulations of three-dimensional, isothermal hydrodynamics often use either the D3Q19 or the D3Q27 velocity sets. While both models correctly approximate Navier-Stokes in the continuum limit, the D3Q19 model is…

Computational Physics · Physics 2018-08-29 Martin Bauer , Ulrich Rüde

We investigate the Boltzmann equation, depending on the Knudsen number, in the Navier-Stokes perturbative setting on the torus. Using hypocoercivity, we derive a new proof of existence and exponential decay for solutions close to a global…

Analysis of PDEs · Mathematics 2020-08-07 Marc Briant