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本文由四个部份组成。第一部份研究时间发展的二维剪切层流动的拓朴结构， 提出了以下拓朴规律：（１）沿零ｕ线。流线的结点和鞍点是交替分布的；流线的鞍点和结 点分别近似对应于压力值最大和最小的位置点：（２）压力值最大和最小的位置点是等压力 线的中心点或鞍点；（３）如果在零ｕ线上某点“０”，出现Ｖ_０（ｘ)０）＝０（）＝０，则流动 的拓朴结构出现分叉，当还有（）＝０时，出现两个涡的合并（＜０）或一个涡的消 失（（）＞０）。如果压力的极值点在某时刻ｔ_０满足Ｊ_Ｐ＝（）＋（）（）＝０和 （）≠０，则等压力线的结构出现分叉。第二部分是用数值模拟验证第一节的拓朴规律， 两者的一致性很好地得到证实。第三部分讨论用数值方法模拟时间发展的剪切层流态的演 化。第四部分是简单的结论。
This article consists of four parts. In the first part, we study the topological structure of two-dimensional shear-layer flow with time development and propose the following topological laws: (1) Along the zero-u-line. The streamline nodes and saddle points are alternately distributed; the saddle points and nodes of the streamline correspond approximately to the maximum and minimum pressure points, respectively: (2) The maximum and minimum pressure points are the center points of the pressure line Or saddle point; (3) If there is a point “0” on zero u line and V_0 (x) 0 = 0 () = 0, then the flowing topology will be bifurcated. , The combination of two vortices (<0) or the disappearance of one vortex (()> 0) appears. If the extremum of pressure satisfies J_P = () + () () = 0 and () ≠ 0 at a certain moment t_0, the structure of isobaric line is bifurcated. The second part verifies the topology of the first section by numerical simulation. The consistency between the two is well verified. The third part discusses the evolution of the shear-layer fluid regime by numerical simulation of temporal evolution. The fourth part is a simple conclusion.