文献类型：会议论文

英文题名：Designing correct fluid hydrodynamics on a rectangular grid using MRT lattice Boltzmann approach

作者：Zong, Yuan[1,2];Peng, Cheng[2];Guo, Zhaoli[3];Wang, Lian-Ping[2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]Univ Delaware, Dept Mech Engn, 126 Spencer Lab, Newark, DE 19716 USA;[3]Huazhong Univ Sci & Technol, Natl Lab Coal Combust, Wuhan 430074, Peoples R China

会议论文集：11th ICMMES Conference

会议日期：JUL 14-18, 2014

会议地点：New York, NY

语种：英文

外文关键词：Rectangular grid; Multiple-relaxation time; Lattice Boltzmann method; Navier-Stokes equations

摘要：While the lattice Boltzmann method (LBM) has become a powerful numerical approach for solving complex flows, the standard lattice Boltzmann method typically uses a square lattice grid in two spatial dimensions and cubic lattice grid in three dimensions. For inhomogeneous and anisotropic flows, it is desirable to have a LBM model that utilizes a rectangular grid. There were two previous attempts to extend the multiple-relaxation time (MRT) LBM to a rectangular lattice grid in 2D, however, the resulting hydrodynamic momentum equation was not fully consistent with the Navier-Stokes equation, due to anisotropy of the transport coefficients. In the present work, a new MRT model with an additional degree of freedom is developed in order to match precisely the Navier-Stokes equation when a rectangular lattice grid is used. We first revisit the previous attempts to understand the origin and nature of anisotropic transport coefficients by conducting an inverse design analysis within the Chapman-Enskog procedure. Then an additional adjustable parameter that governs the relative orientation in the energy-normal stress subspace is introduced. It is shown that this adjustable parameter can be used to fully eliminate the anisotropy of transport coefficients, thus the exact Navier-Stokes equation can be derived on a rectangular grid. Our theoretical findings are confirmed by numerical solutions using three two-dimension benchmark problems, i.e. the channel flow, the cavity flow, and the decaying Taylor-Green vortex flow. The numerical results demonstrate that the proposed model shows remarkably good performance with appropriate choice of model parameters. (C) 2015 Elsevier Ltd. All rights reserved.