Turbulent Spot/Separation Bubble Interactions in a Spatially Evolving Supersonic Boundary-Layer Flow
نویسندگان
چکیده
The growth and breakdown of localised disturbances into a turbulent spot in a Mach 2 boundary-layer flow have been investigated by direct numerical simulation. In particular, the interaction of a turbulent spot with a shock-induced separation bubble is studied. The primary vortex structures triggered by the injected low momentum fluid and the metamorphosis of the hairpin structures into a turbulent spot are clearly identified in the present study. The spot-separation bubble interaction is found to enhance the breakdown of the hairpin structures i.e. is capable of advancing the transition process. A substantial increase in the lateral spreading of the spot is observed due to the spot/bubble interaction. Locally averaged profiles of the flow quantities within the spot show behaviour similar to developed turbulent flows.
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