动态中子输运方程的修正时间离散格式  

Modified Time Discrete Scheme for Time-Dependent Neutron Transport Equation

作　　者：洪振英[1] 袁光伟[1] 傅学东[1] 阳述林[1] 

机构地区：[1]北京应用物理与计算数学研究所,北京100094

出　　处：《核动力工程》2010年第S2期34-37,共4页Nuclear Power Engineering

基　　金：国家重点基础研究发展计划(973计划)(2005CB321703);中国工程物理研究院基金(2008A0202008;2010A0202009)

摘　　要：传统方法很少考虑时间步长对数值格式的影响,导致关于时间微分的物理量出现振荡,数值计算结果的精度较低。针对自适应时间步长的特点,对球几何动态中子输运方程的时间离散格式进行了研究,构造了修正时间离散格式。数值算例表明:修正时间离散格式简单且精度较高,所需迭代次数较少,避免了时间步长变化带来的数值解的振荡,更加适合自适应时间步长的计算。The classical time discrete scheme does not consider the self adaptive time step and the physical quantity about differential quantity for time variable exits numerical oscillation.Therefore,the numerical precision is very poor.In this paper the time discrete scheme is studied for the spherical time-dependent neutron transport equation.The modified time discrete scheme is constructed for self adaptive time step.The numerical results show that the modified time discrete scheme is very simple and has more accurate numerical precision.The iteration number for modified time discrete scheme is lower than that of the conventional exponential method and diamond difference.Furthermore,the differential curve on time about flux is more smooth than that of the exponential method and diamond difference.

关 键 词：指数格式 菱形格式 修正时间离散格式 

分 类 号：O241.82[理学—计算数学]