Turbulent flow structure characterization of angled injection into a supersonic crossflow

An experimental analysis of the three-dimensional, turbulent, compressible flow structure of a highly underexpanded Mach 1.8 jet injected at an angle of 25 deg into a Mach 2.9 freestream is described. The experimental methods include cross-film anemometry, conventional mean-how probes (pitot and cone-static pressure), schlieren photography, and surface oil-flow visualization. The mean-how data consist of axial mass flux, y-z plane mass flux vector, and total pressure contour plots. Turbulence data include x, y, and z mass flux turbulence intensity components, x-y and x-z Reynolds shear stresses, and anisotropy coefficients. Two relatively large recirculation cells were located just downstream of the injector. In addition, the vortex pair within the plume dramatically affected the overall mean and turbulent flow structure. The axial turbulence intensity had two peaks that were collocated with the vortex pair. The transverse and spanwise intensities peaked on the right and left sides of the plume, respectively. The anisotropy contours also showed a strong dependence on the secondary motion of the two counter-rotating vortices. In particular, the z-y coefficient had a maximum located within one vortex, and a minimum in the other.