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In this paper, we study a time discrete scheme for the initial value problem of the ES-BGK kinetic equation. Numerically solving these equations are challenging due to the nonlinear stiff collision (source) terms induced by small mean free…

Numerical Analysis · Mathematics 2010-04-01 Francis Filbet , Shi Jin

The numerical method of dynamical low-rank approximation (DLRA) has recently been applied to various kinetic equations showing a significant reduction of the computational effort. In this paper, we apply this concept to the linear…

Numerical Analysis · Mathematics 2024-11-12 Lena Baumann , Lukas Einkemmer , Christian Klingenberg , Jonas Kusch

We present a simple and general approach to formulate the lattice BGK model for high speed compressible flows. The main point consists of two parts: an appropriate discrete equilibrium distribution function (DEDF) $\mathbf{f}^{eq}$ and a…

Soft Condensed Matter · Physics 2015-06-16 Yanbiao Gan , Aiguo Xu , Guangcai Zhang , Yang Yang

Despite a long record of intense efforts, the basic mechanisms by which dissipation emerges from the microscopic dynamics of a relativistic fluid still elude a complete understanding. In particular, no unique pathway from kinetic theory to…

Computational Physics · Physics 2017-08-16 A. Gabbana , M. Mendoza , S. Succi , R. Tripiccione

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

In this paper, we present two novel Asymptotic-Preserving Neural Networks (APNNs) for tackling multiscale time-dependent kinetic problems, encompassing the linear transport equation and Bhatnagar-Gross-Krook (BGK) equation with diffusive…

Numerical Analysis · Mathematics 2023-12-12 Shi Jin , Zheng Ma , Keke Wu

The objective of this paper is to propose a hyperbolic relaxation technique for the dispersive Serre-Green-Naghdi equations (also known as the fully non-linear Boussinesq equations) with full topography effects introduced in Green, A.E. and…

Numerical Analysis · Mathematics 2022-01-19 Jean-Luc Guermond , Chris Kees , Bojan Popov , Eric Tovar

We consider in this paper a velocity discretized version of the full linear kinetic BGK model and the corresponding limit for small Knudsen number, the linearised Euler or acoustic system. Considering these equations on networks, coupling…

Analysis of PDEs · Mathematics 2026-03-09 Raul Borsche , Tobias Damm , Axel Klar , Yizhou Zhou

Electrostatic structures have been observed in many regions of space plasmas, including the solar wind, the magnetosphere, the auroral acceleration region. One possible theoretical description of some of these structures is the concept of…

Plasma Physics · Physics 2020-02-06 C. S. Ng

In this paper, three-dimensional (3D) multi-relaxation time (MRT) lattice-Boltzmann (LB) models for multiphase flow are presented. In contrast to the Bhatnagar-Gross-Krook (BGK) model, a widely employed kinetic model, in MRT models the…

Computational Physics · Physics 2015-06-26 Kannan N. Premnath , John Abraham

With the aim of better understanding the numerical properties of the lattice Boltzmann method (LBM), a general methodology is proposed to derive its hydrodynamic limits in the discrete setting. It relies on a Taylor expansion in the limit…

Fluid Dynamics · Physics 2022-01-05 Gauthier Wissocq , Pierre Sagaut

In this article, we propose a generalized non-equilibrium chemical kinetics model from \textit{ab initio} simulation data obtained using accurate potential energy surfaces developed recently for the purpose of studying high-temperature air…

Fluid Dynamics · Physics 2020-07-15 Narendra Singh , Thomas Schwartzentruber

The relaxation rates to the invariant density in the chaotic phase space component of the kicked rotor (standard map) are calculated analytically for a large stochasticity parameter, $K$. These rates are the logarithms of the poles of the…

chao-dyn · Physics 2009-10-31 M. Khodas , S. Fishman , O. Agam

Thermodynamic nonequilibrium effects play a central role in momentum and energy transport in compressible flows. In conventional BGK kinetic models, the relaxation time $\tau$ is taken as a constant, which neglects the dependence of the…

Fluid Dynamics · Physics 2026-05-19 Demei Li , Zhongyi He , Huilin Lai , Yanbiao Gan , Hailong Liu , Pengfei Lin

We present a microscopic approach to quantum dissipation and sketch the derivation of the kinetic equation describing the evolution of a simple quantum system in interaction with a complex quantum system. A typical quantum complex system is…

Quantum Physics · Physics 2009-10-31 Aurel Bulgac , Giu Do Dand , Dimitri Kusnezov

In the Hermite-expansion-based multiple-relaxation-time lattice Boltzmann (LB) model [Shan & Chen, Int. J. Mod. Phys. C, 18, 635, (2007)], a separate relaxation time is assigned to each of the tensorial moments of the collision term. Here…

Computational Physics · Physics 2021-05-05 Xuhui Li , Xiaowen Shan

We present a new rheological model depending on a real parameter $\nu \in [0,1]$ that reduces to the Maxwell body for $\nu=0$ and to the Becker body for $\nu=1$. The corresponding creep law is expressed in an integral form in which the…

Geophysics · Physics 2018-03-01 Francesco Mainardi , Enrico Masina , Giorgio Spada

The lattice Boltzmann equation describes the evolution of the velocity distribution function on a lattice in a manner that macroscopic fluid dynamical behavior is recovered. Although the equation is a derivative of lattice gas automata, it…

comp-gas · Physics 2008-02-03 James D. Sterling , Shiyi Chen

In this paper we consider the equilibrium problem in the relaxed linear model of micromorphic elastic materials. The basic kinematical fields of this extended continuum model are the displacement $u\in \mathbb{R}^3$ and the non-symmetric…

Mathematical Physics · Physics 2014-03-17 Patrizio Neff , Ionel-Dumitrel Ghiba , Markus Lazar , Angela Madeo

A kinetic model for granular mixtures is considered to study three different non-equilibrium situations. The model is based on the equivalence between a gas of elastic hard spheres subjected to a drag force proportional to the particle…

Soft Condensed Matter · Physics 2025-02-27 Pablo Avilés , David González Méndez , Vicente Garzó