Richtmyer-Meshkov instability coupled with a chemical reaction*

The Richtmyer-Meshkov Instability (RMI) and the resulting mixing at the impulsively-accelerated interface between two fluids is of great importance in astrophysics, proposed high-speed combustion systems, and pursuits towards inertial confinement fusion. Past experimental studies of the RMI have typically used inert gases, whereas in the applications of interest involving the RMI, the instability occurs concurrently with either chemical or nuclear reactions. Here we present the first experiments investigating the RMI coupled with a chemical reaction.  The experiments are performed in a vertical, downward-firing shock tube.  The initial interface consists of a shear layer between a 94% He/6% acetone mixture and Ar, above and below the interface, respectively (the acetone is added to perform planar laser-induced fluorescence).  To create the shear layer, in past experiments Ar and the He/acetone mixture were flowed horizontally (immediately above and below the interface, respectively).  In the present experiments, an 85% O₂/15% Kr mixture replaces the Ar in the horizontal injection.  A M=1.9 planar shock wave accelerates the interface, and upon reshock the acetone/O₂ mixture ignites.  Initial visualization experiments are presented here.