Discrete unified gas kinetic scheme for all Knudsen number flows: Low-speed isothermal case

作     者：Zhaoli Guo Kun Xu Ruijie Wang 

作者机构：State Key Laboratory of Coal Combustion Huazhong University of Science and Technology Wuhan 430074 China Department of Mathematics Hong Kong University of Science and Technology Clear Water Bay Hong Kong China Nano Science and Technology Program Hong Kong University of Science and Technology Clear Water Bay Hong Kong China 

出 版 物：《Physical Review E》 (物理学评论E辑：统计、非线性和软体物理学)

年 卷 期：2013年第88卷第3期

页      面：033305-033305页

核心收录：

学科分类：07[理学] 070203[理学-原子与分子物理] 0702[理学-物理学] 

基　　金：National Natural Science Foundation of China Hong Kong Research Grant Council HKUST Research Fund [SRFI11SC05] 

主　　题：DISCRETE systems KNUDSEN flow ISOTHERMAL flows FINITE volume method DISTRIBUTION (Probability theory) LATTICE Boltzmann methods 

摘      要：Based on the Boltzmann-BGK (Bhatnagar-Gross-Krook) equation, in this paper a discrete unified gas kinetic scheme (DUGKS) is developed for low-speed isothermal flows. The DUGKS is a finite-volume scheme with the discretization of particle velocity space. After the introduction of two auxiliary distribution functions with the inclusion of collision effect, the DUGKS becomes a fully explicit scheme for the update of distribution function. Furthermore, the scheme is an asymptotic preserving method, where the time step is only determined by the Courant-Friedricks-Lewy condition in the continuum limit. Numerical results demonstrate that accurate solutions in both continuum and rarefied flow regimes can be obtained from the current DUGKS. The comparison between the DUGKS and the well-defined lattice Boltzmann equation method (D2Q9) is presented as well.