Aspects of shock wave-induced vortex breakdown

In this article, we discuss supersonic vortex breakdown when sufficiently strong streamwise vortices encounter otherwise planar, normal and oblique shock fronts as well as solid surfaces placed in their passages. The dramatic destruction of a streamwise vortex during supersonic vortex interactions reveals a vortex breakdown similar in many ways to the well-documented incompressible vortex bursting. The main features of supersonic vortex breakdown include formation of a spherically blunt-nosed conical shock, and a vortex core, which upon crossing the apex of the conical shock expands into a subsonic turbulent conical region. A notable characteristic of the supersonic vortex breakdown is the formation of an entropy-shear layer separating an inner subsonic zone containing the burst structure from the surrounding supersonic flow. Numerical, experimental, and analytical studies of shock wave/vortex interactions are discussed and results from wind tunnel studies involving head-on collision of supersonic vortices with surfaces are presented.