LAUSR

The present paper presents comparisons of the vortex identification between the omega method and the Q criterion based on the data of a classical flow. From the comparisons of the vortex structure together with the flow statistics, some important conclusions are drawn on the validity of the two methods, as follows. The omega method can identify various kinds of vortices with different intensities (e.g., the strong vortex, the medium vortex and the weak vortex). For the Q criterion, due to the subjective threshold selection, only the strong vortex with weak deformations could be identified. Finally, some emerging topics related with the advanced vortex identification methods are briefly discussed.