发表机构
École Nationale des Ponts et Chaussées, Institut Polytechnique de Paris, CNRS; Inria Paris(法国国立路桥学校,巴黎理工学院,法国国家科学研究中心; 法国国家信息与自动化研究所巴黎分部)
机构由 AI 辅助整理,请以论文原文为准。AI 中文总结
针对中子物理学中带振荡系数的反应-扩散本征问题,采用多尺度有限元方法(MsFEM)并结合均匀化与滤波思想构造基函数,通过数值实验验证了该方法的有效性。
AI 中文摘要
我们研究具有振荡扩散系数和反应系数的反应-扩散本征问题,其中反应系数的幅值较大:由周期均匀化理论确定的校正方程同时涉及扩散算子和反应算子。我们采用多尺度有限元方法(MsFEM)对该问题进行数值近似,这是一种经典的有限元类方法,它针对振荡问题在特定的、依赖于问题的基函数集上进行Galerkin近似,基函数在离线阶段预先计算。受均匀化理论启发并结合部分滤波思想,我们展示了如何定义这些基函数以获得高效方法。我们针对该问题的标量形式(此时为自伴问题)和矢量形式(此时通常为非自伴问题),在周期和非周期情形下开展了大量数值实验,验证了该方法的性能,部分理论分析补充了数值结果。
英文摘要
We consider reaction-diffusion eigenproblems with oscillatory diffusion and reaction coefficients. The reaction coefficient magnitude is large: the corrector equation identified by periodic homogenization involves both the diffusion and the reaction operators. We study the numerical approximation of this problem using the Multiscale Finite Element Method (MsFEM). This now classical method is a finite element type method that performs a Galerkin approximation of the oscillatory problem on a specific, problem dependent, basis set. The basis functions are precomputed in an offline stage. Inspired by homogenization theory and using some filtering ideas, we show how to define these basis functions in order to obtain an efficient method. The comprehensive set of numerical experiments that we present, in periodic and non-periodic cases, for the scalar-valued version of the problem (which is then self-adjoint) and for the vector-valued version of the problem (which is then in general non self-adjoint), demonstrates the performance of the approach. Some theoretical arguments complement the numerical observations.