三维积分变分节块中子输运并行计算方法研究

Research on Parallel Computing Method of 3D Integral Variational Neutron Transport

为节约计算时间,提出了一种适用于三维积分变分节块中子输运计算的并行计算方法。采用积分方法替代了传统球谐函数方法(PN),以提高响应矩阵的构造效率和低阶角度展开时的计算精度;同时考虑响应矩阵构造、矩阵方程求解时非重叠空间区域的可并行性,开发了基于信息传递接口(MPI)的并行算法和程序。针对TAKEDA2基准题开展的校核计算表明,当节块表面的PN阶数为3阶,采用20个计算核心并行计算时,积分变分节块法的总并行效率可达到95%。本文为大规模问题的中子输运并行计算提供了一种精确高效的求解思路。

In order to save the computational time,this study proposes a parallel computing method suitable for three-dimensional variational nodal neutron transport calculation.The integral method is employed instead of the traditional spherical harmonics method to improve the formation efficiency of response matrix and the calculation accuracy with low-order PN transport.At the same time,considering the parallelism between non-overlapping subdomains when response matrix is constructed and matrix equation is solved,a parallel algorithm and program based on Message-Passing-Interface(MPI)are developed.When PN order of node interfaces is 3,the integral variational nodal method parallel computing with 20 cores for TAKEDA2 problem achieved a parallel efficiency of 95%.This paper provides an efficient solution to the transport calculation for large-scale problems.