一种改进的流场计算加速收敛方法

探讨了二维非结构网格无粘流场计算的加速方法。在对残差平均和多重网格这两种主要加速方法进行分析后，提出了一种改进的兼具多重网格思想的残差平均方法。经对绕NACA0012翼型无粘流动计算的验证，收效明显。在几乎不增加计算量的情况下，比原有的残差平均方法可减少迭代步25%～30%.该思想可推广用于三维、有粘流动计算和结构化网格中。

MODIFIED RESIDUAL AVERAGE METHOD TO ACCELERATE CONVERGENCE

The Euler equations are solved numerically for 2 D steady flow on unstructured triangular grids with special concern on converging preformance. Using a cell centered upwind finite volume method, the flow solver utilizes a three stage Runge Kutta time integration scheme with Roe's flux function. The convergence of the solver is accelerated by local time stepping and residual average methods. The solver is speeded up more by modifying residual average with careful examination of the relation between residue average and multi grid methods. The numerical algorithm is applied for flow over an NACA 0012 airfoil with satisfactory effect. Compared with the original method, the modified method can decrease 20% 30% running time without increasing work effort. The developed method can be used in numerical simulation of three dimensional viscous flow, and on structured grids with ease.