Interaction between the bow shock of a vehicle with the shock waves generated by a wing or control surface are a vital design consideration, due to the potentially high localized heat transfer rates in the interaction region. For this reason a large amount of work has been done in an attempt to classify and predict shock interaction phenomena.
A series of experiments was conducted in the Princeton University Mach 8 Wind Tunnel to study shock inter-actions on axisymmetric double-cone geometries. Schlieren images and surface-pressure data were taken. Two models were tested, which were expected to produce steady Type VI and Type V shock interactions. The experiments are compared to computational fluid dynamics calculations, and the features of these complicated flow fields are discussed. The comparison is excellent for the laminar Type VI shock interaction. The computations accurately reproduce the size of the separation zone and the surface pressure. However, for the Type V interaction the laminar computation overpredicts the size of the separation region. In addition, the experimental results for the Type V interaction show that the size of the separation region decreases with increasing Reynolds number, whereas the laminar computations predict the opposite trend. Turbulent computations show much better agreement with experimental data and reproduce the experimentally observed relationship between the size of the separation region and the Reynolds number, indicating that the reattachment shocks cause transition to turbulence in these flows.
Comparison of experimental and computational schlieren images.
