格子Boltzmann方法多层网格负载均衡算法优化研究  

Optimization Study of the Load Balancing Algorithm in the Multi-Layer Lattice Boltzmann Method

作　　者：何鹏 王良军 张武[2] 朱文浩[1] HE Peng;WANG Liang-jun;ZHANG Wu;ZHU Wen-hao(School of Computer Engineering and Science,Shanghai University,Shanghai 200444,China;School of Mechanics and Engineering Science,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学计算机工程与科学学院,上海200444 [2]上海大学力学与工程科学学院,上海200072

出　　处：《电子学报》2024年第9期3097-3110,共14页Acta Electronica Sinica

基　　金：国家自然科学基金(No.61873156,No.91630206)。

摘　　要：基于格子Boltzmann方法的多层网格局部加密技术,通过多尺度网格计算不同层次的流动特征,避免了单层均匀笛卡尔网格中的低效率与计算资源的浪费,但仍存在并行性能上的不良影响.本文考虑并行计算中的负载均衡效应,从单层网格出发,通过考虑多层网格的运算特点来研究基于负载均衡的网格划分方法.同时,将网格划分与程序实现进行分离,在单层和多层网格中均完成了任意网格划分下的并行计算.在单层网格中,以二维血管流动的不同并行策略为例,研究了负载量划分与不同进程的各自时间开销的关系.在多层网格中,首先论述了多尺度网格在运算顺序上的特征,其次以三种不同的多层网格验证二维翼型绕流的计算结果,最后在每种网格中均使用三种不同的网格划分方法进一步探讨负载均衡与时间开销的关系.在128核的高性能计算平台上进行并行性能测试,强可扩展性可达到60%左右,弱可扩展性可达到82.78%.这种高可扩展性结果表明本文通过改进负载均衡性能,明显提升了多层网格计算中的并行性能.The local encryption technique for multi-layer grids based on the lattice Boltzmann method computes the flow characteristics at different levels through multi-layer grids,which avoids the inefficiency and waste of computational re⁃sources in single-layer uniform Cartesian grids.But there is still an undesirable effect on the parallel performance.The loadbalancing effect in parallel computing is considered in this paper.Starting from a single-layer grid,we study the load-balanc⁃ing-based grid partitioning method by considering the computational characteristics of multi-layer grids.At the same time,the grid partitioning is separated from the program implementation,and parallel computation with arbitrary grid partitioning is achieved in both single-layer and multi-layer grids.The relationship between load partitioning and the respective time over⁃heads of the different processes is investigated in a single-layer grid with different parallel strategies for 2D vascular flow.The characteristics of multiscale grids with respect to the order of operations is first discussed for multi-layer grids.Second,three different multi-layer grids are used to verify the computational results of the two-dimensional aerofoils.Finally,the re⁃lationship between load balancing and time overhead is further investigated by using three different meshing methods in each grid.Parallel performance tests on a 128-core HPC(High Performance Computing)platform show that the strong scalability can reach up to 60%,and the weak scalability can reach 82.78%.This high scalability result shows the significant improve⁃ment of the parallel performance in multi-layer grid computing by improving the load balancing performance.

关 键 词：格子BOLTZMANN方法 多层网格 大规模并行计算 负载均衡 

分 类 号：TP312[自动化与计算机技术—计算机软件与理论]