Two-Dimensional Krypton Tagging Velocimetry (KTV-2D) Investigation of Shock-Wave/Turbulent Boundary-Layer Interaction

Abstract

Preliminary results from a two-dimensional Krypton Tagging Velocimetry (KTV-2D) investigation of a Mach 2.75 turbulent boundary and 24 degree compression corner flow are presented in this paper. KTV-2D is performed by creating a grid of tagged Kr atoms formed by intersecting laser lines and imaging the resulting fluorescence at a write step; then, after a time delay, imaging the translation of the grid by re-exciting the tagged atoms for the read step. The measurements were made in a 99% N2 and 1% Kr gas mixture. Spatial correlation was used to extract the velocity from the data. It was found that the streamwise component of the velocity in the boundary layer agrees well with the literature; however, a consistent bias was noted in the wall-normal velocity component in the boundary-layer and compression corner flows and we provide an explanation and correction for this bias which will easily be eliminated in future experimentation (the bias was a result of procedure, not inherent in the technique). The turning angle in the compression corner flow matches the result from classical inviscid theory, bringing confidence to the results.