Analysis Seminar

The talk is to give an overview on the (in)stability of classical boundary layers in fluid dynamics that were introduced by Prandtl in 1904 to approximate viscous flows near a solid boundary in the small viscosity limit. In particular, near boundary layers with an inflection point, the classical Ansatz is incorrect due to an emergence of thinner viscous sublayers, which could remarkably reach to an order one in its amplitude. Near generic stable boundary layers, these sublayers may still become unstable due to the classical viscous destabilization phenomena. The talk is based on a series of recent joint works with E. Grenier (ENS Lyon).