For correct identification of vortices, this paper first analyzes the properties of the rigid vortex core and its induced flow field given by the Rankine vortex model, and it is concluded that the concentrated vortex structure should consist of the vortex core and the induced flow field (the potential flow region with a weak shear layer). Then the vortex structure is analyzed by using the Oseen vortex model. Compared with the Rankine vortex, the Oseen vortex is a concentrated vortex with a deformed vortex core. The vortex structure consists of the vortex core region, the transition region and the shear layer region (or the potential flow region). The transition region reflects the properties of the resultant vorticity of the same magnitude and the resultant deformation rate of the shear layer, and the transition region also determines the boundary of the vortex core. Finally, the evolution of leading-edge vortices of the double-delta wing is numerically simulated. And with different vortex identification methods, the shape and the properties of the leading-edge vortices identified by each method are analyzed and compared. It is found that in the vorticity concentration region, the vortices obtained by using ω, λ₂, Ω criteria and Q criteria are basically identical when appropriate threshold values are adopted. However, in the region where the vorticity is dispersed, due to the influence of the flow viscous effect and the adverse pressure gradient, the results obtained by different vortex identification methods can be quite different, as well as the related physical properties, which need to be further studied.

为了正确识别旋涡，本文首先分析了兰金旋涡模型给出的刚性旋涡核的特性及其诱导的流场，并得出结论，集中的旋涡结构应由旋涡核和诱导的流场组成（具有弱剪切层的潜在流动区域）。然后通过使用Oseen涡模型分析涡结构。与朗肯旋涡相比，Oseen旋涡是具有变形旋涡芯的集中旋涡。涡流结构由涡流芯区域，过渡区域和剪切层区域（或潜在流动区域）组成。过渡区域反映了相同幅度的合成涡度和剪切层合成变形率的特性，过渡区域也决定了涡旋核的边界。最后，数值模拟了双三角翼前缘涡旋的演变。并用不同的涡旋识别方法，对每种方法识别出的前沿涡旋的形状和性质进行了分析和比较。发现在涡度集中区域，通过使用ω，λ ₂，Ω标准和Q当适当的阈值通过的标准基本上都是相同的。但是，在涡度分散的区域，由于流动粘性效应和不利的压力梯度的影响，通过不同的涡旋识别方法获得的结果以及相关的物理性质可能会有很大的不同，需要有待进一步研究。