Feedback Boundary Stabilization to Trajectories for 3D Navier–Stokes Equations.

Given a nonstationary trajectory of the Navier–Stokes system, a finite-dimensional feedback boundary control stabilizing locally the system to the given trajectory is derived. Moreover the control is supported in a given open subset of the boundary of the domain containing the fluid. In a first step a controller (feedback operator) is derived which stabilizes the linear Oseen–Stokes system “around the given trajectory” to zero; for that a corollary of a suitable truncated boundary observability inequality, the regularizing property for the system, and some standard techniques of the optimal control theory are used. Then it is shown that the same controller also stabilizes, locally, the Navier–Stokes system to the given trajectory. [ABSTRACT FROM AUTHOR]