基于通量展开节块法的六角形时-空动力学方程数值解

提出了一种基于节块内瞬态中子通量展开的六角形几何时一空动力学方程数值解法．在该方法中，各群中子通量分布用解析基函数和二阶正交多项式近似展开，而包含各组缓发中子先驱核浓度的固定源项则利用多项式进行近似．将面平均偏流及其一次矩作为节块之间的耦合条件，不但明显改善了节块耦合关系，而且使得响应矩阵技术比较容易地应用于迭代求解过程．对二维、三维基缝问题计算表明，该方法能高教、准确地给出各时间寿内的堆芯总功率和节块功率分布。

Numerical Solution for Space-Time Kinetics Equation in Hexagonal-z Geometry Based on Flux Expansion Nodal Method

An efficient nodal method for the hexagonal-z geometry was proposed. In this numerical solution of space-time kinetics equation in method, the intranodal flux distributions are expanded by analytic basis functions and orthogonal second-order polynomials for each group, and the fixed source terms including delayed neutron precursor concentration are approximated in terms of polynomials. The zero-and first-order moments of partial currents are adopted as the nodal coupled conditions, which not only greatly improve the nodal coupling relations, but also considerably facilitate the utilization of the response matrix technique for the iterative solution of spacetime kinetics equation. The numerical results for the two-and three-dimensional benchmark problems show that the transient core powers and nodal power distributions can be predicted accurately in each time-step calculations.