It is found that the vortex structures include the Kelvin?like vortexes in shear?layer of jet, the cross?flow separation vortex pair, the horseshoe vortex system in upstream bottom region of jet and the wake vortexes.

• 发现主要有4类旋涡,即射流主体周缘剪切层的类开尔文涡列、横流绕流分离旋涡、射流喷口前缘的马蹄涡系和尾迹涡。