空气动力学学报2001，Vol.19Issue(1)：1-7,7.
Navier-Stokes(NS)方程组差分计算中的物理和网格尺度效应及NS方程组的简化
Effects of physical and grid scales in difference computing of the Navier-Stokes(NS) equations and computing generalized NS-equa tions
摘要
Abstract
Effects of physical and grid scales in difference computing of NSequations are analyzed and emphasis is on coupling of fluid mechanics with numerical analysis. The study shows that in normal conditions of NS-difference computing, some viscous terms will dropinto the truncated error terms of modified differential equation of NS differen ce scheme. In this case, NS computation is actually equal to compute a certain simplified NS equations, moreover, computing repeatedly these viscous error terms yield unpredictable influence on numerical solution. In order to avoid above-cited shortcoming, one way is to raise accuracy of NS difference scheme and to fine grid and to realized a veritable computation of NS equations. The other way is to reduce reasonably NS equations. For this end we suggest a generalized NS eq uations derived by neglecting those error viscous terms from NS equations. The generalized NS equations, in which viscous terms retained are only second-order shear viscous terms, may save time and storage and avoid unpredictable influence of error accumulations of error viscous terms on numerical solution. As two exa mples, both generalized NS (GNS) equations and NS equations are used to compute the supersonic flows over both frontward and rearward facing steps. Numerical re sults of GNS equations agree well with those of NS equations.关键词
计算流体力学/尺度效应/Navier-Stokes（NS）方程组/广义NS方程组分类
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高智,申义庆..Navier-Stokes(NS)方程组差分计算中的物理和网格尺度效应及NS方程组的简化[J].空气动力学学报,2001,19(1):1-7,7.基金项目
国家自然科学基金项目 （）
