EFFECT OF CYLINDER-WALL JUNCTURE CONFIGURATION IN SUPERSONIC FLOW

This thesis examined the effect of variations in the geometry of the juncture of a cylinder at a flat plate. The effect on the pressure and skin friction on the face and surroundings were examined. When compared to the experimental data obtained under similar conditions, the computational cases had a slightly higher pressure, with a qualitatively similar profile. Four cases were considered: a simple baseline configuration, a pedestal, a gap, and a fairing. The results of the pedestal case displayed this behavior to an extreme, exaggerating all the jumps and dips in the experiment. The RMS pressure was examined to investigate the shock foot locations and again the experiment and computation matched very closely. When looking at the flow visualizations and spectra, the gap case showed a larger concentration of skin friction magnitude at the base as well as the highest intensity of the low frequencies at separation and reattachment, as well as an observed higher frequency activity like Liu observed in his computations. For the new fairing case that was introduced, very similar properties to the pedestal case were observed when looking at the pressure, skin friction, and even spectra, but the flow visualization in the wake showed that it was much closer in structure to the baseline case. The small differences between the computational and experimental data could be attributed to the turbulence model used as well as the uncertainty in the pressure sensitive paint technique used in the experiments. In this thesis it was found that the gap case had higher fluctuations and skin friction, the new fairing case was very similar to the pedestal and baseline case, and the experimental data matched well for most of the computations.