散射问题中消除多次透射边界飘移失稳措施比较分析  

Comparison of measures for eliminating drift instability of transmitting boundary in scattering problems

作　　者：杨宇[1,2] 李小军[2] 贺秋梅[2] 纪忠华[1] 

机构地区：[1]环境保护部核与辐射安全中心,北京100082 [2]中国地震局地球物理研究所,北京100081

出　　处：《地震工程与工程振动》2014年第5期1-6,共6页Earthquake Engineering and Engineering Dynamics

基　　金：国家重点基础研究发展计划资助(2011CB013601);环保公益项目(201309056);国家自然科学基金重大研究计划(91215301)

摘　　要：多次透射边界是一种广泛应用的人工边界,但类似于其它局部人工边界,它也存在计算稳定性问题。本文分析了多次透射边界低频飘移失稳的原因,通过数值试验对已有的消除飘移失稳措施进行了比较分析,并给出了在散射问题中已有消飘措施的适用性:γ修正算子法的参数确定没有一个明确的标准,完全依靠经验性试算,使用上应注意参数的取值控制;降阶消飘方法的关键在于失稳趋势的判定,不存在方法参数的选取,实现上可控性较好。The multi-transmitting boundary is a local artificial boundary widely used in numerical simulation of the near-field wave motion in infinite media. But like other artificial boundaries,the multi-transmitting boundary has the instability of numerical simulation. Based on the cause of drift instability,the applicability of previously used stability measures is discussed by numerical experiment in scattering problems. The method of adding modified operator γ is needed to be carefully used because of the empirical feature and uncertainty of parameter value. We recommend the method of reduced order because the key to this method is to judge the trend of instability and selecting parameter value is not considered in this method. The controllability of numerical realization is achieved more easily by the method of reduced order.

关 键 词：波动模拟 多次透射边界 低频飘移失稳 降阶消飘 修正算子 

分 类 号：P315.9[天文地球—地震学] P315.3[天文地球—固体地球物理学]