2023/10/12 by Gauthier Wissocq, Rémi Abgrall, Wissocq, Gauthier +1
Mathematics · Physics and Astronomy · #65M06 #65M08 #76N06 #Advanced Thermodynamics and Statistical Mechanics #FOS: Mathematics #Gas Dynamics and Kinetic Theory #Mathematical Biology Tumor Growth #Numerical Analysis (math.NA)
paper · pdf · doi:10.48550/arxiv.2310.08356
openalex publication_date 2023/10/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose a numerical approach, of the BGK kinetic type, that is able to approximate with a given, but arbitrary, order of accuracy the solution of linear and non-linear convection-diffusion type problems: scalar advection-diffusion, non-linear scalar problems of this type and the compressible Navier-Stokes equations. Our kinetic model can use finite advection speeds that are independent of the relaxation parameter, and the time step does not suffer from a parabolic constraint. Having finite speeds is in contrast with many of the previous works about this kind of approach, and we explain why this is possible: paraphrasing more or less \citegolse:hal-00859451, the convection-diffusion like PDE is not a limit of the BGK equation, but a correction of the same PDE without the parabolic term at the second order in the relaxation parameter that is interpreted as Knudsen number. We then show that introducing a matrix collision instead of the well-known BGK relaxation makes it possible to target a desired convection-diffusion system. Several numerical examples, ranging from a simple pure diffusion model to the compressible Navier-Stokes equations illustrate our approach