摘要
作为一种典型的钝体绕流,方柱绕流具有物体几何外形简单而流场结构非常复杂的特性,常规的基于RANS的数值计算方法难以准确模拟。DNS不使用任何湍流模型,直接求解完整的非定常流动控制方程组,模拟包括脉动在内的湍流所有非定常流动量的时空演变过程,是湍流数值模拟中最精确的方法,在复杂流动数值模拟方面的应用潜力巨大。本文自主设计和编制并行数值模拟程序,使用基于"神威·太湖之光"国产CPU架构的大规模并行计算,开展了中等雷诺数(Re=10 000)方柱绕流的直接数值模拟。其中:不可压N-S方程组采用基于交错网格的有限体积法离散;压力-速度耦合采用SIMPLE算法处理;离散得到的代数方程组采用Gauss-Seidel迭代求解;时间步进采用Euler隐式格式,对流项采用QUICK格式,耗散项采用中心差分格式;数值模拟程序的并行化使用MPI方法处理。文中重点分析了方柱绕流的复杂涡系结构,同时给出了部分湍流统计结果,并通过与RANS和LES模拟结果的对比分析,展现了DNS在复杂精细流场模拟方面的优势。
Flow past square cylinder has the property of simple geometric shape but very complex flow field structure, which makes itself a typical object of the research of the flow past bluff body. The usual numerical method such as RANS can not simulate it accurately. While Direct Numerical Simulation(DNS) is considered to be the most accurate method of turbulent flow numerical simulating, which solves the whole governing equations of the unsteady flow directly without using any turbulence model and can simulate the time evolution process of all the turbulent instantaneous flow parameter including the fluctuation motion in the flow, and makes itself the most potential method in the simulation of the complex flow field.In this paper, parallel code of DNS is designed and programmed, numerical computation of medium Reynolds number(Re=10 000) flow past square cylinder is carried out on large-scale parallel computer system of Sunway Taihu-Light with homebred CPU frame. The incompressible N-S equations are discretized by the finite volume method with staggered grid system. SIMPLE scheme is used for solving the pressurevelocity coupling. Gauss-Seidel iteration method is used to solve the algebraic equations. Fully implicit scheme is used for the discretization of temporal terms. QUICK scheme is adopted for the convection term and centric difference scheme for the dissipation term. The code is parallelized by MPI method. Emphasis is put on the analysis of the vortex structure in the flow field and some statistical results are presented also. The results are compared with these simulated by RANS and LES method to present the advantage of DNS on the simulation of complicated flow field.
作者
王建春
吴乘胜
王星
徐金秀
WANG Jian-chun;WU Cheng-sheng;WANG Xing;XU Jin-xiu(China Ship Scientific Research Center, Wuxi 214082, China;Jiangnan Computing Technology Research Institute, Wuxi 214081, China)
出处
《船舶力学》
EI
CSCD
北大核心
2019年第8期893-905,共13页
Journal of Ship Mechanics
基金
装备预研重点实验室基金（614220301010117）
关键词
直接数值模拟
方柱绕流
涡系结构
MPI并行
国产CPU架构
DNS(Direct Numerical Simulation)
flow past square cylinder
vortex structure
MPI(Message Passing Interface)
homebred CPU frame
作者简介
王建春(1989-),男,工程师,E-mail:664148138@qq.com;吴乘胜(1976-),男,研究员.
