摘要
采用 Green定理将有限元积分方程中的对流项变量从微分算子中分离出来 ,从插值函数入手建立迎风格式 ,解决了在 Galerkin有限元方法中不易引入迎风格式的问题。通过建立局部斜迎风格式及对几个典型问题的数值模拟 ,表明了该方法用于对大 Peclet数流动及复杂区域流动的数值模拟是可行的。
In their paper, Saabas et al tried to suppress false diffusion in convection-dominated flow calculations . We propose a method that can be more effective in suppressing such false diffusion. Analyzing Galerkin finite element method and Navier-Stokes' equations, we find that formulating an upwind interpolation scheme for convection variable is an efficient strategy for reducing false diffusion. Based on this finding, we use Green′s theorem to separate the convection variable from the differiential operator in weighted residual equation; in this way, the characteristic of upwind interpolation scheme remains intact because it is not affected by the differential operator during the discretization process. We applied our strategy to three typical test problems: two pure convection flows and one high Reynolds number fluid flow. In all three examples, we take 2-dimensional 4-node quadrilateral elements and a locally skewed upwind interpolation scheme on 2×2 Gauss integral points; we combined them with equal-order velocity-pressure formulations. Figs. 2, 3, 4(a) and 5 do show preliminarily that our method can be quite effective in suppressing false diffusion in convection-dominated flow calculations.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2001年第4期511-514,共4页
Journal of Northwestern Polytechnical University
