The effects of four expansion regions (centered and gradual expansions of both 7 and 4 deg) on a fully devolped Mach 3 turbulent boundary layer were investigated. Instantaneous visualizations were made possible by the presence of scalar water condensation in the freestream and its absence in the higher temperature boundary layer. The elongated longitudinal structures previously found in the flat plate boundary layer are present downstream of the expansions. Large-scale structures increase in scale across the expansions. Structure angles also initially increase but are found to return to the flat plate value 10delta downstream of the 7-deg centered expansion. The rapid quenching of small-scale turbulence by the expansions results in a more intermittent boundary layer visually doninated by large-scale structures. Convection velocities derived from double-pulse correlations are reasonable in the flat plate and 7-deg centered expansion boundary layers. Excess condensation downstream of the 14-deg expansions (probably CO2) made the 14-deg expansion results more difficult to interpret.
Structure of supersonic turbulent boundary layer after expansion regions
Struktur von turbulenten Überschallrandschichten hinter Expansionsbereichen
AIAA Journal ; 33 , 3 ; 430-438
1995
9 Seiten, 13 Bilder, 35 Quellen
Article (Journal)
English
Structure of Supersonic Turbulent Boundary Layer After Expansion Regions
Online Contents | 1995
|Supersonic, Turbulent Boundary-Layer Separation
AIAA | 1974
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