解析函数展开节块法的数值稳定性分析  

Numerical Stability Analysis for Analytic Function Expansion Nodal Method

作　　者：孙伟[1,2] 李庆[2] 王侃[1] 

机构地区：[1]清华大学工程物理系,北京100084 [2]中国核动力研究设计院核反应堆系统设计技术重点实验室,四川成都610041

出　　处：《原子能科学技术》2014年第5期872-876,共5页Atomic Energy Science and Technology

摘　　要：解析函数展开节块法是求解六角形几何堆芯中子注量率的常用方法,其核心思想是利用严格满足中子扩散方程的解析基函数,直接把节块内的各群中子注量率近似展开。研究发现,此方法在求解一些特殊问题时,出现计算发散的情况。针对此类问题,提出了两种解决方法:截断近似方法和泰勒展开方法。通过对改造后的VVER440基准题验证表明:这两种方法在保证计算精度的基础上很好地解决了解析函数展开节块法的数值不稳定性问题。Analytic function expansion nodal method is often used to solve hexagonal geometry reactor problems w hose kernel is that the intra-nodal flux distribution is expanded in a series of analytic basic functions for each group .In some cases ,this meth-od is not convergence and two stabilization techniques are introduced to resolve the instability problem .One is truncation approximation and the other is Taylor expansion . Compared with the VVER440 benchmark results ,both techniques not only ensure the calculation accuracy but also give a good solution for numerical instability problems .

关 键 词：六角形几何 解析函数展开节块法 数值稳定性 

分 类 号：TL325[核科学技术—核技术及应用]