On modeling Richtmyer–Meshkov turbulent mixing widths

Abstract

We present several observations concerning the Richtmyer–Meshkovmixing widths after a shock or reshock passes through the interface between two fluids. The mixing evolves with two oppositely-moving fronts: A bubble (b) side into the heavier fluid and a spike (s) side into the lighter fluid. Our first observation concerns the reference surface used to partition the total mix width, hb+s, into separate hb and hs widths. Next, we point out that if and when hb and hs obey power-laws tθ with separate θb and θs, then hb+s cannot be given, except as an approximation, by a single θb+s. Finally, we describe a fully continuous model for hit, i=b,s, or b+s, as the solution to the “drag equation” with a time-dependent θi(t).