面向跨流域模拟的统一随机粒子方法和SPARTACUS软件  

Unified Stochastic Particle method for the simulation of crossing flow regimes and introduction to the SPARTACUS software

作　　者：冯凯凯 田鹏 张俊[1] Feng Kaikai;Tian Peng;Zhang Jun(School of Aeronautic Science and Engineering,Beihang University,Beijing 100083,China)

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100083

出　　处：《空天技术》2024年第2期108-118,共11页Aerospace Technology

摘　　要：在跨流域气体流动问题的研究中,传统随机粒子算法如直接模拟蒙特卡洛(DSMC)方法由于存在分子平均自由程和平均碰撞时间对计算时空尺度的限制,无法进行高效模拟。统一随机粒子(USP)方法是近年来提出的多尺度粒子方法,该方法通过将分子的运动和碰撞耦合考虑,去除了DSMC方法中计算时空尺度的限制,有效提高了在跨流域流场计算中的效率。介绍了USP方法的基本原理、算法实现和作者团队最近开发的开源求解器SPARTACUS。SPARTACUS在DSMC方法的开源框架SPARTA基础上发展而来,具有出色的通用性,能够对任意1~3维几何外形的内外流场进行计算。此外,该求解器使用基于消息传递接口的并行策略,具有支持上百万核规模并行的潜力。给出了几个针对不同外形、从低速到高超声速的基准测试结果,并与DSMC或实验的参考结果进行对比。结果表明,该求解器能够对跨流域流场进行准确模拟,并与传统粒子方法相比具有显著效率优势。In the study of gas flow across different regimes,traditional stochastic particle methods,such as the Direct Simulation Monte Carlo(DSMC)method,face limitations in efficiently simulating due to constraints imposed by the molecular mean free path and mean collision time on the computational spatiotemporal scales.The Unified Stochastic Particle(USP)method,a multiscale particle approach proposed in recent years,effectively overcomes these limitations inherent in the DSMC method by coupling the motion and collisions of molecules.The fundamental principles,algorithm implementation,and an open-source solver named SPARTACUS(SPARTA Combined with USP),developed by the authors′team are presented.Derived from the open-source framework SPARTA(Stochastic PArallel Rarefied-gas Time-accurate Analyzer),SPARTACUS exhibits excellent versatility,capable of simulating internal and external flows around geometries of arbitrary dimensions.Additionally,the solver employs a parallel strategy based on the Message Passing Interface(MPI),showcasing potential scalability to support parallelism on the order of millions of cores.Several benchmark tests are provided,covering diverse shapes and spanning from low-speed to hypersonic conditions,with comparisons made against reference results from DSMC or experiments.The results demonstrate that SPARTACUS accurately simulates flows across different regimes,showcasing notable efficiency advantages compared to traditional particle methods.

关 键 词：多尺度计算 稀薄气体动力学 随机粒子方法 临近空间飞行 直接模拟蒙特卡洛 SPARTA 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程] V411