基于GCMR的中子输运方程模拟加速算法研究

Research on Acceleration Algorithm for Simulation of Neutron Transport Equation Based on GCMR

特征线方法(MOC)由于较强的复杂几何适应能力,广泛用于中子输运方程的求解。但是MOC方法存在收敛速度慢、计算耗时长的问题,因此目前普遍采粗网有限差分法(CMFD)对MOC求解过程进行加速。然而目前常用的CMFD方程不能保证偏中子流守恒,同时在一些情况下存在发散的问题。为此考虑采用广义粗网再平衡方法(GCMR)对MOC求解过程进行加速。推导了基于GCMR方法的中子通量求解方程,并在DRAGON程序中加入了GCMR加速模块。最后结合C5G7-2D基准题对GCMR算法进行了验证,并与CMFD加速方法进行了对比。结果表明,GCMR具有与CMFD相同的加速效果,但是求解精度优于CMFD。

For its outstanding capability to treat complex geometry,Method of Characteristic(MOC)is widely used in solving neutron transport equations.But the calculation is extraordinarily time consumption for the slow convergence rate of MOC.The Coarse Mesh Finite Difference method(CMFD)is the common method to accelerate the calculating process.But the traditional CMFD cannot preserve the partial currents,and divergent behavior is observed under some conditions.So Generalized Coarse Mesh Rebalance method(GCMR)was used to accelerate the solution procedure for neutron transport equations by MOC.The equation of average neutron flux was derivated based on GCMR.A GCMR accelerating module was developed for DRAGON.The C5 G7-2 D benchmark was used to validate the GCMR algorithm,and the results of GCMR and CMFD were also compared.The results show that GCMR has an identical acceleration effect with CMFD,but the accuracy of GCMR is better than CMFD.