Spectral stability of Prandtl boundary layers: an overview
  In this paper we show how the stability of Prandtl boundary layers is linked to the stability of shear flows in the incompressible Navier Stokes equations. We then recall classical physical instability results, and give a short educational presentation of the construction of unstable modes for Orr Sommerfeld equations. We end the paper with a conjecture concerning the validity of Prandtl boundary layer asymptotic expansions. 
Emmanuel Grenier, Yan Guo, Toan T. Nguyen
math.AP math-ph math.MP