高保真中子输运计算的多级加速理论及应用  

Study and Application of Multi-level Acceleration Theory for High-fidelity Neutron Transport Calculation

作　　者：郝琛 朱雁凌 康乐 李佩军 周晓宇 HAO Chen;ZHU Yanling;KANG Le;LI Peijun;ZHOU Xiaoyu(Fundamental Science on Nuclear Safety and Simulation Technology Laboratory,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]哈尔滨工程大学核安全与仿真技术国防重点学科实验室,黑龙江哈尔滨150001

出　　处：《原子能科学技术》2022年第2期296-307,共12页Atomic Energy Science and Technology

基　　金：国家自然科学基金(12075067);国家重点研发计划(2018YFE0180900)。

摘　　要：为解决高保真中子输运计算耗时严重的问题,本文提出了多级加速理论。其中,针对迭代求解过程,采用迭代加速的思路,即通过等价的低分辨率系统加速以减少迭代次数;针对瞬态求解,采用时间步加速方法,通过建立多级预估校正系统,实现在大时间步长下开展准确的高保真中子输运计算。最终引入不同分辨率系统的概念,将时间步加速方法与迭代加速方法整合形成一套完整的多级加速理论,并将其应用到精细化中子物理计算程序HNET中。采用典型瞬态基准题验证HNET程序加速效果。数值结果表明:多级加速理论能够在保证高保真中子输运计算精度的同时,极大地提升计算效率。In order to solve the time-consuming problem of high-fidelity neutron transport calculation,the multi-level acceleration theory was proposed.For iterative process,the iterative acceleration was utilized to ease the computational burden.An equivalent low resolution system with different spaces,energy and angular resolutions was built,forming the multi-level iterative acceleration.The solution of low resolution system can provide good initial value for high resolution system,so the number of iterations for high resolution system calculation was greatly reduced.For the purpose of ensuring the complete equivalence among different resolution systems,the generalized equivalence theory based coarse mesh finite difference method was used in iterative process.Aiming at transient solution,the time-step acceleration was adopted to decrease the calculating amount of high-fidelity neutron transport by establishing a multi-level predictor-corrector system.Based on the idea of predictor-corrector,the time step of high-fidelity transient neutron transport calculation was divided into multiple levels.Meanwhile,the corresponding low resolution systems were established under different time resolutions,so as to effectively capture the characteristics of neutron flux density in different resolutions.Then the low resolution system result was used to adjust the predicted solution of high resolution system step by step,thereby achieving accurate high-fidelity neutron transport calculation under large time steps.Ultimately,the concept of time,space,energy,and angular resolution system were introduced,and the time-step acceleration and iterative acceleration were integrated into a complete multi-level acceleration theory.Furthermore,the theory was applied to the high-fidelity neutron transport program HNET and a specific implementation scheme was established,which includes four levels of acceleration in time step scale,three levels of acceleration in space scale,and two levels of acceleration in energy scale.The acceleration performance o

关 键 词：精细化中子输运计算 多级加速理论 迭代加速 时间步加速 

分 类 号：TL32[核科学技术—核技术及应用]