A multi-level parallel solver for rarefied gas flows in porous media
A multi-level parallel solver for rarefied gas flows in porous media
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DOI：
10.1016/j.cpc.2018.08.009
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发表时间：
2019-01-01
影响因子：
6.3
通讯作者：
Zhang, Yonghao
中科院分区：
文献类型：
--
作者：
Minh Tuan Ho;Zhu, Lianhua;Zhang, Yonghao
为了实现多孔介质中稀薄流动的孔隙尺度模拟，开发了一种高性能的多级并行气体动力学求解器。采用离散速度法和迭代格式求解Bhatnagar-Gross-Krook模型方程。实现多级MPI/OpenMP并行化，目的是有效利用计算资源，首次基于数字岩石图像直接模拟多孔介质中的稀薄气体流动。对多级并行算法进行了详细的分析，证实了多级并行算法的性能优于单一的MPI处理迭代算法。通过高通信效率和适当的CPU进程负载均衡，在1536核的2D模拟中并行效率达到94%，在12288核的3D模拟中并行效率达到81%。虽然在空间空间中的分解不影响仿真结果，但这种方法的另一个好处是子域的数量可以保持最小，以避免迭代过程的收敛速度恶化。这种多层次并行方法可以很容易地推广到解决其他玻尔兹曼模型方程。(C) 2018年作者。这是一篇基于CC by许可的开放获取文章。
A high-performance gas kinetic solver using multi-level parallelization is developed to enable pore-scale simulations of rarefied flows in porous media. The Bhatnagar-Gross-Krook model equation is solved by the discrete velocity method with an iterative scheme. The multi-level MPI/OpenMP parallelization is implemented with the aim to efficiently utilize the computational resources to allow direct simulation of rarefied gas flows in porous media based on digital rock images for the first time. The multi-level parallel approach is analyzed in detail confirming its better performance than the commonly-used MPI processing alone for an iterative scheme. With high communication efficiency and appropriate load balancing among CPU processes, parallel efficiency of 94% is achieved for 1536 cores in the 2D simulations, and 81% for 12288 cores in the 3D simulations. While decomposition in the spatial space does not affect the simulation results, one additional benefit of this approach is that the number of subdomains can be kept minimal to avoid deterioration of the convergence rate of the iteration process. This multi-level parallel approach can be readily extended to solve other Boltzmann model equations. (C) 2018 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.