圆柱突然起动的快速涡解法

 文中将Chorin的涡方法、格子涡(VIC)方法和快速Fourier变换(FFT)相结合,发展了一套快速有效的求解高Re数下非定常N-S方程的算法(快速涡方法)。通过对二维圆柱突然起动问题的数值计算,得到流动分离及其演化过程(包括二次涡及二次涡对的生成);此外还得到回流区对称轴线上速度分布。这些结果与实验数据及其它数值解相比,是令人满意的。该程序对其它高Re数非定常流动问题也是适用的。

NUMERICAL STUDY OF UNSTEADY FLOWS AROUND AN IMPULSIVELY STARTED FROM REST CIRCULAR CYLINDER BY FAST VORTEX METHOD

An effective numerical method (fast vortex method) to solve unsteady N-S equations at high Reynolds number, combining Chorin's vortex scheme with the Vortex-in-Cell (VIC) method and the Fast Fourier Transforms (FFT), is presented in this paper. The scheme has successfully calculated the early stage flows of two dimensional circular cylinder which impulsively started from rest. The process of separation and evolution with time of the flow, the generation of the secondary vortex and the pair of the secondary vortex, and the radial velocity on the symmetry axis behind the cylinder, etc., are studied in detail. The comparison with the careful experimental data and other accurate numerical results is satisfactory. The program is also available for other problems of unsteady flow at high Reynolds number.