A New Diffusing-Vortex Numerical Scheme

本文提出了一种求解二维非定常流场的扩散涡方法。 不可压缩Navier-Stokes方程，将得到推广， 应用到外部不可压缩的粘性流动， 通常光滑的钝体。 数字优势超过其他 拉格朗日涡方法将进一步证明， 减少总的CPU时间，并避免切断程序。 的 一种新的方法，它是绿色的近似表达式 扩散方程的函数，将被构造为一个 一般二维光滑轮廓在高雷诺数。 一个基准案例，圆柱体问题将被用来检查 编码的精度和空间网格长度的影响 和时间步长对计算结果的影响。 提出的有限差分分析基于 扩散涡方法可以应用于非定常流场， 二维不可压缩粘性绕流 典型的圆形、椭圆形和其他类型的圆柱体， CPU时间比涡旋方法少一个数量级。

A diffusing-vortex method, for solving the two-dimensional incompressibl Navier-Stokes equation, will be extended and applied to the external incompressible viscous flow over a generally smooth blunt body. The numerical advantages over other Langrangian vortex methods will be further demonstrated by reducing total CPU time and by avoiding cut-off procedures. The new approach, which is an approximate expression of the Green's function of the diffusion equation, will be constructed for a general two-dimensional smooth contour at a high Reynolds number. A benchmark case, the cylinder problem will be used to examine the accuracy of the code and the effect of spatial mesh length and time step length on computational results. The proposed finite difference analysis based on the diffusing vortex method can be applied to the unsteady imcompressible viscous flow past two dimensional geometry typical of circular, elliptic, and other type of cylinders with CPU time less than vortex method by one order of magnitude.