Analysis of multipolar vortices in the interaction of a shock with a strong moving vortex

Abstract

Numerical simulation results of a convecting shielded vortex interacting with a normal shock are presented. The shock and vortex Mach numbers covered are on the higher side, for which relatively little information is available. It is well known that for a weak shock the vortex survives the shock, and for stronger shocks it breaks down. We discover that there is a narrow zone of shock and vortex strengths for which the vortex neither preserves its shape, nor does it break down in the true sense, but generates a tripole or quadrupole — structures that have not so far been reported in shock-vortex interaction studies. A number of cases have been studied to determine the different shock-vortex interaction patterns depending on shock and vortex Mach numbers. A new type of interaction pattern has been determined and it has been named as Type-IV interaction.