A multiscale kinetic-fluid solver with dynamic localization of kinetic effects

JOURNAL OF COMPUTATIONAL PHYSICS

卷:229

Article

Degond, Pierre²  Dimarco, Giacomo^1,2,3  Mieussens, Luc⁴ 

[1] Univ Toulouse 3, UMR 5219, Inst Math Toulouse, CNRS, F-31062 Toulouse, France

[2] Univ Toulouse, UPS, INSA, UT1,UTM,Inst Math Toulouse, F-31062 Toulouse, France

[3] CEA Saclay DM2S SFME, CEA, F-91191 Gif Sur Yvette, France

[4] Univ Bordeaux, Inst Math, F-31062 Toulouse, France

关键词: Kinetic-fluid coupling;    Multiscale problems;    Boltzmann-BGK equation;   

DOI  :  10.1016/j.jcp.2010.03.009

来源: Elsevier

【 摘 要 】

This paper collects the efforts done in our previous works [7,9,10] to build a robust multiscale kinetic-fluid solver. Our scope is to efficiently solve fluid dynamic problems which present non-equilibrium localized regions that can move, merge, appear or disappear in time. The main ingredients of the present work are the followings ones: a fluid model is solved in the whole domain together with a localized kinetic upscaling term that corrects the fluid model wherever it is necessary; this multiscale description of the flow is obtained by using a micro-macro decomposition of the distribution function [9]; the dynamic transition between fluid and kinetic descriptions is obtained by using a time and space dependent transition function; to efficiently define the breakdown conditions of fluid models we propose a new criterion based on the distribution function itself. Several numerical examples are presented to validate the method and measure its computational efficiency. (c) 2010 Elsevier Inc. All rights reserved.

【 授权许可】

Free