Separated flows overview Video 4
Video 15. Marginal separation near the leading edge of an aerofoil. Notice the small size of the separation bubble, the loss of stability in the separated shear layer due to Kelvin-Helmholtz instability, and the reattachment of the boundary layer.
These videos, all available on YouTube, are demonstrated in the introductory lecture for the module on separated flows, MSc in Advanced Computational Methods for Aeronautics, Department of Aeronautics, Imperial College London.