The head of hair - pin vortex rise to the center of the pipe and horse - shoe vortex is formed . then the horse - shoe vortex detaches from hair - pin vortex and form isolated ring - like vortex 首先發(fā)卡渦的頭部在向圓管中心抬升的過(guò)程中,會(huì)形成馬蹄渦,馬蹄渦從發(fā)卡渦頭部脫離后,形成孤立的環(huán)形渦。