期刊
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
卷 304, 期 -, 页码 479-500出版社
ELSEVIER SCIENCE SA
DOI: 10.1016/j.cma.2016.02.032
关键词
Helmholtz equation; Finite element method; Nitsche's method; Acoustic impedance; Surface wave; Garding inequality
资金
- Swedish Foundation for Strategic Research [AM13-0029]
- Swedish Research Council [621-2013-3706]
We propose a new finite element method for Helmholtz equation in the situation where an acoustically permeable interface is embedded in the computational domain. A variant of Nitsche's method, different from the standard one, weakly enforces the impedance conditions for transmission through the interface. As opposed to a standard finite-element discretization of the problem, our method seamlessly handles a complex-valued impedance function Z that is allowed to vanish. In the case of a vanishing impedance, the proposed method reduces to the classic Nitsche method to weakly enforce continuity over the interface. We show stability of the method, in terms of a discrete Garding inequality, for a quite general class of surface impedance functions, provided that possible surface waves are sufficiently resolved by the mesh. Moreover, we prove an a priori error estimate under the assumption that the absolute value of the impedance is bounded away from zero almost everywhere. Numerical experiments illustrate the performance of the method for a number of test cases in 2D and 3D with different interface conditions. (C) 2016 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据