...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Computer Methods in Applied Mechanics and Engineering >Finite element method for time dependent scattering: nonreflecting boundary condition, adaptivity, and energy decay
【24h】

Finite element method for time dependent scattering: nonreflecting boundary condition, adaptivity, and energy decay

机译：时变散射的有限元方法：非反射边界条件，适应性和能量衰减

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

An adaptive finite element method is developed for acoustic wave propagation in unbounded media. The efficiency and high accuracy of the method are achieved by combining an exact nonreflecting boundary condition [SIAM J. Appl. Math. 55 (1995) 280; J. Comput. Phys. 127 (1996) 52] with space-time adaptivity [East-West J. Numer. Math. 7(4) (1999) 263]. Hence the computational effort is concentrated where needed, while the artificial boundary can be brought as close as desired to the scatterer. Both features combined yield high accuracy and keep the number of unknowns to a minimum. An energy inequality is derived for the initial-boundary value problem at the continuous level. Together with an implicit second order time discretization it guarantees unconditional stability of the semi-discrete system. The resulting fully discrete linear system that needs to be solved every time step is unsymmetric but can be transformed into an equivalent sequence of small nonsymmetric and large symmetric positive definite systems, which are efficiently solved by conjugate gradient methods. Numerical examples illustrate the high accuracy of the method, in particular in the presence of complex geometry.
机译：针对声波在无边界介质中的传播，提出了一种自适应有限元方法。该方法的效率和高精度是通过组合精确的非反射边界条件来实现的。数学。 55（1995）280; J.计算机物理127（1996）52]具有时空适应性[East-West J. Numer。数学。 7（4）（1999）263]。因此，计算工作集中在需要的地方，同时可以使人造边界尽可能接近散射体。两种功能的结合产生了高精度，并将未知数降至最低。对于连续水平的初边值问题，得出了能量不等式。再加上隐式的二阶时间离散化，可以保证半离散系统的无条件稳定性。最终需要在每个时间步求解的完全离散线性系统都是非对称的，但是可以将其转换为小的非对称和大对称正定系统的等效序列，可以通过共轭梯度法对其进行有效求解。数值例子说明了该方法的高精度，特别是在存在复杂几何形状的情况下。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号