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arXiv 2201.05354math.NAcs.NA
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任意格子玻尔兹曼格式的有限差分公式

Finite Difference formulation of any lattice Boltzmann scheme

Thomas Bellotti, Benjamin Graille, Marc Massot

AI总结:

该研究提出任意格子玻尔兹曼格式均可改写为守恒变量上的多步有限差分格式,构建了基于算子、交换代数和多项式的形式体系,可借助有限差分的分析工具研究格子玻尔兹曼格式的一致性与稳定性,并通过数值算例验证了有效性。

摘要:

格子玻尔兹曼格式依赖于扩大目标问题的规模,以高度可并行化且高效的类动力学方式求解偏微分方程(PDE),该过程分为碰撞阶段和迁移阶段。尽管从计算角度来看这种结构具有众所周知的优势,但它并不适合构建关于目标方程的严格一致性概念,也无法提供精确的稳定性定义。为了弥补这些不足并引入一个严谨的框架,我们证明了任意格子玻尔兹曼格式都可以改写为对应守恒变量上的多步有限差分格式。这一结果是通过设计一种基于算子、交换代数和多项式的合适形式体系实现的。因此,对应有限差分格式的一致性概念使得我们可以在线性格子玻尔兹曼格式的情况下应用Lax-Richtmyer定理。此外,我们还表明,格子玻尔兹曼格式中常用的类von Neumann稳定性分析,完全等价于其对应有限差分格式的von Neumann稳定性分析。更广泛地说,有限差分格式分析的常用工具如今可直接用于研究格子玻尔兹曼格式。我们通过数值算例验证了这些工具的适用性。

英文摘要:

Lattice Boltzmann schemes rely on the enlargement of the size of the target problem in order to solve PDEs in a highly parallelizable and efficient kinetic-like fashion, split into a collision and a stream phase. This structure, despite the well-known advantages from a computational standpoint, is not suitable to construct a rigorous notion of consistency with respect to the target equations and to provide a precise notion of stability. In order to alleviate these shortages and introduce a rigorous framework, we demonstrate that any lattice Boltzmann scheme can be rewritten as a corresponding multi-step Finite Difference scheme on the conserved variables. This is achieved by devising a suitable formalism based on operators, commutative algebra and polynomials. Therefore, the notion of consistency of the corresponding Finite Difference scheme allows to invoke the Lax-Richtmyer theorem in the case of linear lattice Boltzmann schemes. Moreover, we show that the frequently-used von Neumann-like stability analysis for lattice Boltzmann schemes entirely corresponds to the von Neumann stability analysis of their Finite Difference counterpart. More generally, the usual tools for the analysis of Finite Difference schemes are now readily available to study lattice Boltzmann schemes. Their relevance is verified by means of numerical illustrations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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