Scaling behavior of density gradient accelerated mixing rate in shock bubble interaction

Variable-density mixing in shock bubble interaction, a canonical flow of Richtermyer-Meshkov instability, is studied by the high-resolution simulation. While dissipation mainly controls passive scalar rate, an objective definition variable-density rate characterizing macroscopic formation still lacking, and fundamental behavior evolution not yet well understood. Here, we first show that interaction distinctly different from previous observations mixing. The widely-accepted hyperbolic conservation moment concentration mixing, i.e., mean concentration, violated flows. We further combine compositional transport equation divergence relation for miscible flows to provide evidence existence density gradient accelerated decomposed term redistributed diffusion term, contributes anomalous decrease or increase depending on Atwood number. Further analyzing number simulations cylindrical spherical bubbles under broad range Mach numbers, Reynolds Peclet exhibits weak dependent identifies with high which can be theoretically predicted based mode violation behavior.