arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2010.04577math.NAcs.NA
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基于密度插值的边界积分方程通用核正则化

General-purpose kernel regularization of boundary integral equations via density interpolation

Luiz M. Faria, Carlos Pérez-Arancibia, Marc Bonnet

摘要:

本文提出了一种适用于二维和三维线性椭圆偏微分方程的Calderón演算的所有四个积分算子的高阶核正则化方法。与以前的密度插值方法一样,该方法依赖于在核奇异点附近对密度函数进行插值,从而将奇异积分和近似奇异积分转换为有界(或更正则)的被积函数.我们在这里提出了一个简单的插值策略,不像以前的方法,不需要显式计算的高阶导数的密度函数沿表面。此外,所提出的方法是内核和维度无关的意义上,寻求密度插值被构造为一个线性组合的点源字段,给出了相同的格林函数中使用的积分方程制定,从而使程序适用,在原则上,任何PDE与已知的格林函数。为了明确起见,我们集中在这里的Nyström方法的(标量)拉普拉斯和亥姆霍兹方程和(矢量)弹性静力学和时间谐波弹性动力学方程。该方法的准确性,灵活性,效率和快速求解器的兼容性证明了通过各种大型三维数值例子。

英文摘要:

This paper presents a general high-order kernel regularization technique applicable to all four integral operators of Calderón calculus associated with linear elliptic PDEs in two and three spatial dimensions. Like previous density interpolation methods, the proposed technique relies on interpolating the density function around the kernel singularity in terms of solutions of the underlying homogeneous PDE, so as to recast singular and nearly singular integrals in terms of bounded (or more regular) integrands. We present here a simple interpolation strategy which, unlike previous approaches, does not entail explicit computation of high-order derivatives of the density function along the surface. Furthermore, the proposed approach is kernel- and dimension-independent in the sense that the sought density interpolant is constructed as a linear combination of point-source fields, given by the same Green's function used in the integral equation formulation, thus making the procedure applicable, in principle, to any PDE with known Green's function. For the sake of definiteness, we focus here on Nyström methods for the (scalar) Laplace and Helmholtz equations and the (vector) elastostatic and time-harmonic elastodynamic equations. The method's accuracy, flexibility, efficiency, and compatibility with fast solvers are demonstrated by means of a variety of large-scale three-dimensional numerical examples.

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