Numerical and experimental investigation of double-cone shock interactions

A series of experiments has been conducted in the Princeton University Mach 8 wind tunnel studying shock interactions on double-cone geometries. Schlieren videos were taken, but the models were not instrumented and thus no surface data are available. Two models were tested, which were expected to produce steady Type VI and Type V shock interactions. The results are compared to laminar computational fluid dynamics calculations, and the features of these complicated flowfields are discussed. The comparison between the experiments and the computations is excellent for the Type VI shock interaction, where the CFD accurately reproduces the size of the separation zone and the shock angles. However, for the Type V interaction the experiments indicate that the flow is unsteady due to a turbulent shock-boundary layer interaction on the afterbody. This unsteadiness cannot be reproduced with the CFD calculations. The mechanism causing this unsteadiness is discussed, and methods to alleviate this problem in future experimental runs are explored.