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arXiv 0708.3533math.NAcs.NA
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解析域上亥姆霍兹问题的基本解法:稳定性与收敛性

Stability and convergence of the Method of Fundamental Solutions for Helmholtz problems on analytic domains

Dartmouth College(达特茅斯学院);The University of Manchester(曼彻斯特大学)

A. H. Barnett, T. Betcke

AI总结:

本文研究解析域上内亥姆霍兹问题中基本解法(MFS)的奇点(电荷点)选择,以实现数值稳定近似,并给出单位圆盘上的完整分析及非凸域上的选择准则,达到典型误差范数10^{-11}。

摘要:

基本解法(MFS)是求解拉普拉斯和亥姆霍兹边值问题的常用工具。其主要缺点是常常导致病态方程组。本文研究解析域上内亥姆霍兹问题中,如何选择MFS基函数的奇点(电荷点),使得近似解能够以数值稳定的方式由MFS基表示。对于单位圆盘上的亥姆霍兹问题,我们给出了包括高频(短波长)极限在内的完整分析。对于更复杂的非凸域(如月牙形域),我们演示了电荷点的正确选择如何与边值问题的解在复平面上的解析延拓范围相关联,而这又取决于域的形状和边界数据。利用这一点,我们开发了一种定位电荷点的方法,使得在多种解析域上典型误差范数可达10^{-11}。在高频情况下,仅需每波长约3个点,这比边界积分方法具有明显优势。

英文摘要:

The Method of Fundamental Solutions (MFS) is a popular tool to solve Laplace and Helmholtz boundary value problems. Its main drawback is that it often leads to ill-conditioned systems of equations. In this paper we investigate for the interior Helmholtz problem on analytic domains how the singularities (charge points) of the MFS basis functions have to be chosen such that approximate solutions can be represented by the MFS basis in a numerically stable way. For Helmholtz problems on the unit disc we give a full analysis which includes the high frequency (short wavelength) limit. For more difficult and nonconvex domains such as crescents we demonstrate how the right choice of charge points is connected to how far into the complex plane the solution of the boundary value problem can be analytically continued, which in turn depends on both domain shape and boundary data. Using this we develop a recipe for locating charge points which allows us to reach error norms of typically 10^{-11} on a wide variety of analytic domains. At high frequencies of order only 3 points per wavelength are needed, which compares very favorably to boundary integral methods.

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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