时间步长对有限容积法数值模拟的影响分析  

Analysis of Influence of Time Step on Numerical Simulation Using Finite Volume Method

作　　者：李渊[1] 朱彤[1] 曹甄俊[1] 

机构地区：[1]同济大学机械工程学院,上海200092

出　　处：《计算机仿真》2009年第3期117-120,共4页Computer Simulation

基　　金：国家自然科学基金资助项目(50206014);上海市曙光计划资助项目(05SG23)

摘　　要：针对时间步长在CFD商业软件中的选取问题,从迭代收敛性和计算精度两个角度,讨论了时间步长对采用有限容积法的数值模拟的作用和影响。从微分方程的离散化入手,分析了时间步长对稳态问题的欠松弛作用,并指出了拟非稳态项与普通松弛因子的区别;通过误差分析指出了如何选取时间步长来提高计算精度,并用计算实例加以佐证。分析表明,时间步长对稳态及非稳态数值模拟都具有重要作用,合理的时间步长应综合考虑稳定性、收敛性和计算精度。In order to choose a reasonable time step in commercial code in CFD field, the influence of time step on numerical simulation using finite volume method was investigated in view of iteration convergence and precision. Starting with the discretization of differential equation, the under - relaxation effect on steady simulation of time step was analyzed and the difference between pseudo transient term and a general under - relaxation factor was pointed out. Based on error analysis, the method of choosing a reasonable time step to improve precision was suggested, and an example was given to support the conclusion. The results demonstrate that time step is of great importance to both the steady and unsteady simulations. In order to choose a reasonable time step, comprehensive consideration of stability and convergence as well as precision should be taken.

关 键 词：时间步长 数值模拟 欠松弛迭代 非稳态 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]