The vortices in the vortex wave flow have particular moving structure, they develop downstream first, stay at the point for a short time, then move upstream.
涡旋波流场中旋涡有其独特的运动规律——先向下游移动，停留很短的时间后，然后向上游移动。
2
Spectrum analysis reveals the frequency characteristics of vortex breakdown point oscillation and spiral wave.
频谱分析确定了破裂点脉动和螺旋波的频率特征。
3
The results also show that in the intensity evolution and the track change of the cyclonic vortex, nonlinear critical point phenomenon appears obviously.