摘要：It is a classical problem in fluid dynamics about the stability and instability of different hydrodynamic patterns in various physical settings, especially in the high Reynolds number limit of laminar flow with boundary effect. In this talk, after reviewing the background and some recent main progress on boundary layer theory, we will present a new approach introduced by Yang-Zhu to study the compressible fluid both on the instability analysis for unsteady flow and high Reynolds number limit for steady problem.