随着中子动力学计算的精度要求以及计算条件的不断提高,如何更好地处理三维时空中子动力学方程的刚性问题对于提高计算效率具有非常重要的工程应用价值。本文应用刚性限制法处理方程组的时间变量,并与空间变量处理方法变分节块法相耦合建立了相应的时空中子动力学计算模型。基准题的数值计算结果表明,刚性限制法可与包括变分节块法在内的各种稳态计算方法耦合以求解时空多群中子动力学问题,且取得了很好的计算精度,允许较大的计算时间步长,以及拥有很好的计算效率。
With the improvement of computational ability and the demand for accuracy requirement of neutron kinetics,it has great value in engineering application to deal with the stiffness of three-dimensional space-time neutron diffusion kinetics better.Based on the stiffness confinement method(SCM)and the variational nodal method(VNM),a new combination of neutron kinetics model was developed.It is demonstrated by the numerical results that the SCM can handle the stiffness problem better with larger time step and higher computational efficiency,and be combined with the VNM.