Inverse Lax-Wendroff procedure for numerical boundary conditions of convection-diffusion equations

JOURNAL OF COMPUTATIONAL PHYSICS

卷:317

Article

Lu, Jianfang¹  Fang, Jinwei²  Tan, Sirui³  Shu, Chi-Wang³  Zhang, Mengping¹ 

[1] Univ Sci & Technol China, Sch Math Sci, Hefei 230026, Anhui, Peoples R China

[2] Harbin Inst Technol, Dept Math, Harbin 150001, Heilongjiang, Peoples R China

[3] Brown Univ, Div Appl Math, Providence, RI 02912 USA

关键词: Convection-diffusion equation;    High order finite difference methods;    Numerical boundary condition;    Inverse Lax-Wendroff method;    Compressible Navier-Stokes equations;   

DOI  :  10.1016/j.jcp.2016.04.059

来源: Elsevier

【 摘 要 】

We consider numerical boundary conditions for high order finite difference schemes for solving convection-diffusion equations on arbitrary geometry. The two main difficulties for numerical boundary conditions in such situations are: (1) the wide stencil of the high order finite difference operator requires special treatment for a few ghost points near the boundary; (2) the physical boundary may not coincide with grid points in a Cartesian mesh and may intersect with the mesh in an arbitrary fashion. For purely convection equations, the so-called inverse Lax-Wendroff procedure [28], in which we convert the normal derivatives into the time derivatives and tangential derivatives along the physical boundary by using the equations, has been quite successful. In this paper, we extend this methodology to convection-diffusion equations. It turns out that this extension is non-trivial, because totally different boundary treatments are needed for the diffusion-dominated and the convection-dominated regimes. We design a careful combination of the boundary treatments for the two regimes and obtain a stable and accurate boundary condition for general convection-diffusion equations. We provide extensive numerical tests for one-and two-dimensional problems involving both scalar equations and systems, including the compressible Navier-Stokes equations, to demonstrate the good performance of our numerical boundary conditions. (C) 2016 Elsevier Inc. All rights reserved.

【 授权许可】

Free