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arXiv 1706.09161physics.comp-phcs.NAmath.NA
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多弛豫时间格子玻尔兹曼方案用于分数输运-扩散方程

Multiple-Relaxation-Time Lattice Boltzmann scheme for Fractional Advection-Diffusion Equation

CEA, Université de Paris-Saclay(法国原子能委员会,巴黎萨克雷大学);Framatome ANP(法马通核能公司);Université d’Avignon et des Pays de Vaucluse(阿维尼翁大学)

Alain Cartalade, Amina Younsi, Marie-Christine Néel

AI总结:

本文提出基于格子玻尔兹曼方法的多弛豫时间方案,用于求解高维分数输运-扩散方程,通过对比随机游走和精确解验证了方法的准确性,克服了BGK方案在各向异性扩散张量和流速不稳定时的局限。

摘要:

本文提出基于格子玻尔兹曼方法的多弛豫时间方案,用于求解高维分数输运-扩散方程,通过对比随机游走和精确解验证了方法的准确性,克服了BGK方案在各向异性扩散张量和流速不稳定时的局限。

英文摘要:

Partial differential equations (p.d.e) equipped of spatial derivatives of fractional order capture anomalous transport behaviors observed in diverse fields of Science. A number of numerical methods approximate their solutions in dimension one. Focusing our effort on such p.d.e. in higher dimension with Dirichlet boundary conditions, we present an approximation based on Lattice Boltzmann Method with Bhatnagar-Gross-Krook (BGK) or Multiple-Relaxation-Time (MRT) collision operators. First, an equilibrium distribution function is defined for simulating space-fractional diffusion equations in dimensions 2 and 3. Then, we check the accuracy of the solutions by comparing with i) random walks derived from stable Lévy motion, and ii) exact solutions. Because of its additional freedom degrees, the MRT collision operator provides accurate approximations to space-fractional advection-diffusion equations, even in the cases which the BGK fails to represent because of anisotropic diffusion tensor or of flow rate destabilizing the BGK LBM scheme.

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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