Recent development of vortex ring impinging onto the wall

It has been more than one hundred years for the study on vortex structure, which is a very important flow structure in the fluid mechanics. Recently, the interaction between vortex ring and solid wall has attracted more and more attentions, for not only it is a very common phenomenon in the engineering, but also it could benefit the understanding of the mechanism of interaction between the vortex and the boundary layer. The interaction between the vortex ring and the wall is reviewed in this paper, including the evolution of vortex ring, the mechanics of vortex ring azimuthal instabilities, the achievements of synthetic vortex ring impinging onto the solid wall, its potential application to heat transfer, and the influence of vortex ring compression. Besides, the latest results of vortex ring impinging onto porous wall are presented, and the future possible investigation direction on this issue is suggested.