A Unified Gas-Kinetic Scheme for Continuum and Rarefied Flows III:Microflow Simulations

作     者：Juan-Chen Huang Kun Xu Pubing Yu 

作者机构：Department of Merchant MarineTaiwan Ocean UniversityKeelung 20224Taiwan Mathematics DepartmentHong Kong University of Science and TechnologyClear Water BayKowloonHong Kong 

出 版 物：《Communications in Computational Physics》 (计算物理通讯（英文）)

年 卷 期：2013年第14卷第10期

页      面：1147-1173页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0704[理学-天文学] 0702[理学-物理学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：Hong Kong Research Grant Council(621709 621011)and grants SRFI11SC05 and RPC10SC11 atHKUST.J.C.Huang was supported by National Science Council of Taiwan through grant No.NSC 100-2221-E-019-048-MY3 

主　　题：Unified scheme non-equilibrium microflow thermal creep flows 

摘      要：Due to the rapid advances inmicro-electro-mechanical systems(MEMS),the study of microflows becomes increasingly ***,the molecular-based simulation techniques are the most reliable methods for rarefied flow computation,even though these methods face statistical scattering problem in the low speed *** discretized particle velocity space,a unified gas-kinetic scheme(UGKS)for entire Knudsen number flow has been constructed recently for flow *** to the particle-based direct simulation Monte Carlo(DSMC)method,the unified scheme is a partial differential equation-based modeling method,where the statistical noise is totally ***,the common point between the DSMC and UGKS is that both methods are constructed through direct modeling in the discretized *** to the multiscale modeling in the unified method,i.e.,the update of both macroscopic flow variables and microscopic gas distribution function,the conventional constraint of time step being less than the particle collision time inmany direct Boltzmann solvers is released *** numerical tests show that the unified scheme is more efficient than the particle-basedmethods in the low speed rarefied flow *** purpose of the current study is to validate the accuracy of the unified scheme in the capturing of non-equilibrium flow *** the continuum and free molecular limits,the gas distribution function used in the unified scheme for the flux evaluation at a cell interface goes to the corresponding Navier-Stokes and free molecular *** the transition regime,the DSMC solution will be used for the validation of UGKS *** study shows that the unified scheme is indeed a reliable and accurate flow solver for low speed non-equilibrium *** not only recovers the DSMC results whenever available,but also provides high resolution results in cases where the DSMC can hardly afford the computational *** thermal creep flow simulation,surprising s