抄録
In the application of vortex rings for material transportation, the collapse of the ring structure resulting from the Widnall instability of a vortex ring decreases its movable distance. The axial flow along a vortex ring core called a "swirl" is numerically superimposed on the normal vortex ring in order to reduce the amplification rate of circumferential waves, and the appearances of vortex structures are observed by means of the iso-vorticity surface. Independent of the thickness of a vortex core, the movable distance of the ring increases once with the axial flow rate enhancement, and then decreases. In addition, the effective factors determining the movable distance are discussed.
