Title: Nonlinear interaction between bulk vortices and the interface in the incompressible Richtmyer-Meshkov instability
Abstract: Nonlinear interaction between bulk point vortices and the interface in the incompressible Richtmyer-Meshkov instability (RMI) is investigated theoretically and numerically. When the strength of point vortices are large enough, they interact with the original vorticity existing on the vortex sheet and create new vortex cores. These vortex cores roll up like mushrooms, and a very complicated interfacial structure is formed at the final stage. It is shown that satellite bubbles and spikes are created in the neighborhood of original bubbles and spikes when bulk point vortices approach the interface. The shape of an interface is largely deformed by the existence of bulk point vortices; however, the asymptotic growth rate of the bubble and spike is almost the same as the one for pure RMI without point vortices.