求解中子输运SP3方程的半解析节块方法

摘要

中子输运简化P3 (SP3)方法是对中子输运方程PN的一种近似,可以转换为与中子扩散方法相似的形式.采用节块方法中有效的半解析方法求解中子输运SP3方程,同时也基于粗网有限差分(CMFD)方法采用细网有限差分(FMFD)形式同样求解该方程.通过对NEACRP-L-336基准题(修改)的数值计算,验证了通过Pin-By-Pin的节块计算能够获得与FMFD几乎相同的结果,而Pin-By-Pin的CMFD计算结果与FMFD计算结果有一定的偏差.%Neutron transport simplified P3(SP3) equation which is an approximation to the neutron transport PN equation, can be transferred to a format similar to the traditional neutron diffusion equation. Solving the SP3 equation is implemented by semi-analytic nodal method which is one of the effective nodal method, and also by coarse mesh finite difference (CMFD) method with fine mesh finite difference (FMFD) format. By numerical analysis of NEACRP L-336 benchmark (modified), it is demonstrated that pin-by-pin nodal calculation can obtain almost the same result as FMFD, but pin-by-pin CMFD result has some deviation to the FMFD result.