Three-Dimensional Morphology of Vortex Interfaces Driven by Rayleigh-Taylor or Richtmyer-Meshkov Instability

We study the 3D topology of Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) single-modes, which includes bubbles, jets and saddle points. We present an analytic description of the interface as a whole, for arbitrary time-dependant acceleration g(t). The dependance of morphology on the lattice - Hexagonal, square or triangular -of bubbles are investigated. RM accelerations in the case of a large density ratio produce jets well separated from each other while, in RT case, jets are connected by liquid sheets. We compare our analytic results to numerical simulations.