分析和PDE讨论班—Metastability of Kolmogorov flows
主 题: 分析和PDE讨论班—Metastability of Kolmogorov flows
报告人: Zhiwu Lin (Georgia Institute of Technology)
时 间: 2017-07-28 14:30-15:30
地 点: 理科1号楼1303
Abstract: We study the metastability of the shear flow siny(Kolmogorov flow) for 2D Navier-Stokes equation on a torus. This flow isnonlinearly stable for the inviscid case. When the viscosity is small enough,it is shown that the non-shear part of the perturbations can decay at a muchfaster rate than the viscous time scale, for an intermediate but long timeperiod. The result is true for the linearized NS equation with any initialvorticity in L2, and for the nonlinear NS equation with initial vorticity of the size of viscosity. We alsoconsider the inviscid damping for two classes of shear flows by using theHamiltonian structures of the linearized Euler equation. This is a joint workwith Ming Xu.