Archive for Rational Mechanics and Analysis

, Volume 200, Issue 3, pp 1075–1097

Inviscid Dynamical Structures Near Couette Flow



Consider inviscid fluids in a channel \({\{-1\leqq y\leqq1\}}\) . For the Couette flow u0 = (y, 0), the vertical velocity of solutions to the linearized Euler equation at u0 decays in time. Whether the same happens at the non-linear level is an open question. Here we study issues related to this problem. First, we show that in any (vorticity) \({H^{s}\left(s<\frac{3}{2}\right)}\) neighborhood of Couette flow, there exist non-parallel steady flows with arbitrary minimal horizontal periods. This implies that nonlinear inviscid damping is not true in any (vorticity) \({H^{s}\left(s<\frac{3}{2}\right)}\) neighborhood of Couette flow for any horizontal period. Indeed, the long time behaviors in such neighborhoods are very rich, including nontrivial steady flows and stable and unstable manifolds of nearby unstable shears. Second, in the (vorticity) \({H^{s}\left(s>\frac{3}{2}\right)}\) neighborhoods of Couette flow, we show that there exist no non-parallel steadily travelling flows \({\varvec{v}\left(x-ct,y\right)}\) , and no unstable shears. This suggests that the long time dynamics in \({H^{s}\left(s>\frac{3}{2}\right)}\) neighborhoods of Couette flow might be much simpler. Such contrasting dynamics in Hs spaces with the critical power \({s=\frac{3}{2}}\) is a truly nonlinear phenomena, since the linear inviscid damping near Couette flow is true for any initial vorticity in L2.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  1. 1.School of MathematicsGeorgia Institute of TechnologyAtlantaUSA

Personalised recommendations