Turbulence characteristics of supersonic turbulent boundary layer reattaching downstream of backward-facing step

The aim of this paper is to clarify the turbulence characteristics of the supersonic boundary layer which is reattaching downstream of a backward-facing step. The boundary layer flow was analyzed by a two-dimensional laser Doppler velocimeter and flow visualizations. The results showed that there was a higher level of momentum exchange between the reattaching boundary layer flow and the main supersonic stream than that of over a flat plate case. Numerical simulation was conducted in this flow field, and the results were compared with the experimental ones. It was clarified that the present CFD code exhibits good performance of simulation for the mean characteristics of flow field, and it was suggested that the improvement of the compressible turbulence model was needed.