基于国产十亿亿次超算系统的近连续过渡流区N-S/DSMC耦合算法并行优化研究
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摘要
过渡流区气动问题的数值模拟一直是空气动力学领域的难点。首先介绍了在已有N-S解算器和DSMC方法研究基础上,采用MPC耦合技术建立N-S/DSMC耦合算法,把DSMC方法和N-S方法的应用范围拓展到近连续过渡流区。然后详述了基于国家超级计算无锡中心的国产十亿亿次超级计算机开展的耦合算法多级并行优化技术,并首次实现了耦合算法的众核并行。测试表明,本文的进程级优化技术取得了超线性加速比;众核级优化受制于原算法特点和系统特点没有取得预期效果,但进行了探讨和分析,为N-S/DSMC耦合算法的众核并行提供了研究和分析依据,为过渡流区高超声速气动特性数值模拟研究提供了有效的途径。
The numerical simulation for near-continuum transitional flow region is a very challenging field of aerodynamics.We first introduce the Navier-Stokes(N-S)resolver and the direct simulation Monte Carlo(DSMC)method,based on which we propose an N-S/DSMC coupling numerical algorithm by developing the modular particle-continuum(MPC)technique.This extends the application range of the DSMC method and the N-S method to the transitional flow region.Then,we explain fully the multilevel parallel optimization techniques of the coupling algorithm on the 100 Psupercomputers in the National Supercomputing Center in Wuxi,and the many-core parallelization is realized for the first time.The tests show that the process-level optimization can obtain super-linear speedup.Though the manycore level optimization does not obtain the expected effect due to the features of the original algorithm and the computer architecture,we make in-depth discussion and analysis.Our research and analysis provide a reference for many-core parallelization of the coupling N-S/DSMC algorithm,and provide an effective approach for the numerical simulations of hypersonic aerodynamics.
The numerical simulation for near-continuum transitional flow region is a very challenging field of aerodynamics.We first introduce the Navier-Stokes(N-S)resolver and the direct simulation Monte Carlo(DSMC)method,based on which we propose an N-S/DSMC coupling numerical algorithm by developing the modular particle-continuum(MPC)technique.This extends the application range of the DSMC method and the N-S method to the transitional flow region.Then,we explain fully the multilevel parallel optimization techniques of the coupling algorithm on the 100 Psupercomputers in the National Supercomputing Center in Wuxi,and the many-core parallelization is realized for the first time.The tests show that the process-level optimization can obtain super-linear speedup.Though the manycore level optimization does not obtain the expected effect due to the features of the original algorithm and the computer architecture,we make in-depth discussion and analysis.Our research and analysis provide a reference for many-core parallelization of the coupling N-S/DSMC algorithm,and provide an effective approach for the numerical simulations of hypersonic aerodynamics.
引文
[1]Schwartzentruber T E,Scalabrin L C,Boyd I D.Hybrid particle-continuum simulations of non-equilibrium hypersonic blunt-body flowfields[J].Journal of Thermophysics and Heat Transfer,2008,22(1):29-37.
[2]Schwartzentruber T E,Scalabrin L C,Boyd I D.Modular implementation of a hybrid DSMC-NS algorithm for hypersonic non-equilibrium flows[C]∥Proc of the 45th AIAAAerospace Sciences Meeting,2007:1-13.
[3]Carlson H A,Boyd I D,Candler G.A hybrid CFD-DSMCmethod of modeling continuum-rarefied flows[C]∥Proc of the 42nd AIAA Aerospace Sciences Meeting and Exhibit,2004:1-8.
[4]Li Zhong-hua,Li Zhi-hui,Li Hai-yan,et al.Application of hybrid N-S/DSMC method in hypersonic transitional flow[C]∥Proc of the 28th International Symposium on Rarefied Gas Dynamics,2012:435-442.
[5]Li Zhong-hua,Li Zhi-hui,Li Hai-yan,et al.Research on CFD/DSMC hybrid numerical method in rarefied flows[J].Acta Aerodynamica Sinica,2013,31(3):282-287.(in Chinese)
[6]Garcia A L,Alder B J.Generation of the chapman-enskog distribution[J].Journal of Computational Phisycs,1998,140(1):66-77.
[7]Xu Jin-xiu,Sun Jun,You Hong-tao,et al.The applied research of OpenACC*many-core programming language on solved Boltzmann equations[J].High Performance Computing Technology,2016,239(2):7-12.(in Chinese)
[8]You Hong-tao,Zhang Li-bo,Mao Zhi-hui.OpenACC2.0VSOpenMP4.0:The comparative study of two mainly many-core programming language based on compiler directives[J].High Performance Computing Technology,2014,227(3):20-25.(in Chinese)
[5]李中华,李志辉,李海燕,等.过渡流区N-S/DSMC耦合计算研究[J].空气动力学学报,2013,31(3):282-287.
[7]徐金秀,孙俊,尤洪涛,等.OpenACC*众核编程语言在求解Boltzmann模型方程的应用研究[J].高性能计算技术,2016,239(2):7-12.
[8]尤洪涛,张立博,毛智辉.OpenACC2.0VS OpenMP4.0:基于编译指示的两种主流众核编程语言的对比研究[J].高性能计算技术,2014,227(3):20-25.
[2]Schwartzentruber T E,Scalabrin L C,Boyd I D.Modular implementation of a hybrid DSMC-NS algorithm for hypersonic non-equilibrium flows[C]∥Proc of the 45th AIAAAerospace Sciences Meeting,2007:1-13.
[3]Carlson H A,Boyd I D,Candler G.A hybrid CFD-DSMCmethod of modeling continuum-rarefied flows[C]∥Proc of the 42nd AIAA Aerospace Sciences Meeting and Exhibit,2004:1-8.
[4]Li Zhong-hua,Li Zhi-hui,Li Hai-yan,et al.Application of hybrid N-S/DSMC method in hypersonic transitional flow[C]∥Proc of the 28th International Symposium on Rarefied Gas Dynamics,2012:435-442.
[5]Li Zhong-hua,Li Zhi-hui,Li Hai-yan,et al.Research on CFD/DSMC hybrid numerical method in rarefied flows[J].Acta Aerodynamica Sinica,2013,31(3):282-287.(in Chinese)
[6]Garcia A L,Alder B J.Generation of the chapman-enskog distribution[J].Journal of Computational Phisycs,1998,140(1):66-77.
[7]Xu Jin-xiu,Sun Jun,You Hong-tao,et al.The applied research of OpenACC*many-core programming language on solved Boltzmann equations[J].High Performance Computing Technology,2016,239(2):7-12.(in Chinese)
[8]You Hong-tao,Zhang Li-bo,Mao Zhi-hui.OpenACC2.0VSOpenMP4.0:The comparative study of two mainly many-core programming language based on compiler directives[J].High Performance Computing Technology,2014,227(3):20-25.(in Chinese)
[5]李中华,李志辉,李海燕,等.过渡流区N-S/DSMC耦合计算研究[J].空气动力学学报,2013,31(3):282-287.
[7]徐金秀,孙俊,尤洪涛,等.OpenACC*众核编程语言在求解Boltzmann模型方程的应用研究[J].高性能计算技术,2016,239(2):7-12.
[8]尤洪涛,张立博,毛智辉.OpenACC2.0VS OpenMP4.0:基于编译指示的两种主流众核编程语言的对比研究[J].高性能计算技术,2014,227(3):20-25.