Validation of an instability growth model using particle image velocimetry measurements

A varicose-profile, thin layer of heavy gas ( SF6) in lighter gas (air) is impulsively accelerated by a planar, Mach 1.2 shock, producing the Richtmyer-Meshkov instability. We present the first measurements of the circulation in the curtain during the vortex-dominated, nonlinear stage of the instability evolution. These measurements, based on particle image velocimetry data, are employed to validate an idealized model of the nonlinear perturbation growth.