A scenario for oblique shock wave induced vortex breakdown

The dramatic flow reorganization observed in experiments involving strong oblique shock wave/vortex interactions could have significant implications for supersonic aircraft. Development of a predictive technique for determining the type of flow structure resulting from a particular vortex/shock combination is therefore of great interest. Thus far the three-dimensional nature of oblique shock wave/vortex interaction has made its measurement and analysis difficult in both experimental and numerical simulation frameworks. As an alternative, the problem has been examined here from a physically intuitive standpoint in order to better understand its dominant features. This approach has enabled a fluid dynamic scenario involving supersonic vortex breakdown to be developed as an explanation for the observed flow reorganization. An approximate analysis for predicting oblique shock wave induced vortex breakdown was developed using this scenario. Results of the analysis for some experimentally investigated vortex/shock combinations indicate that the prediction of vortex breakdown corresponds closely with the appearance of a fully developed separated shock structure upstream of the original oblique shock plane. This con-elation is seen as strong circumstantial evidence that vortex breakdown is responsible for the dramatic changes observed in the interaction flowfields.