Hunt for unstable coherent structures begins

A striking feature all simulations share are recognizable recurrent structures (rolls, streaks, ....)

That is the observation that motivates all that follows: numerical searches for steady state or equilibrium solutions, their state space visualization.


A symmetry detour: Plane Couette Navier-Stokes equations are invariant under several obvious symmetries (translations, flips). This observation is very helpful for the analysis of the flow. It is also a bit technical... so skip this unless interested