Effect of wall vortices on RMI shock tube experiments

The Richtmyer-Meshkov Instability (RMI) is frequently studied in shock tubes, where the walls and relatively narrow cross sections introduce boundary layers that influence the development of the RMI. Traditional RMI analysis assumes statistically two-dimensional flow and sufficient distance from wall effects; however, previous work has shown that vortices form in the boundary layer upon re-shock due to baroclinic vorticity deposition. Experiments investigating this phenomenon were conducted in the Wisconsin Shock Tube Laboratory at UW-Madison using planar laser-induced florescence and particle image velocimetry for the cases of a Mach 1.56 & 1.25 shock wave and an interface with Atwood numbers of 0.7 and 0.5. The results look at the temporal development of these vortices as well as the overall effects shock strength and Atwood number have on these wall vortices.