Stabilization of nonautonomous Navier-Stokes flows under dynamic slip boundary conditions
Buddhika Priyasad, Sérgio S. Rodrigues
TL;DR
This work proves exponential stabilization for the incompressible Navier–Stokes equations under dynamic slip boundary conditions, driving the flow toward a prescribed time-dependent trajectory without relying on spectral properties. A constructive feedback law is developed using oblique projections and a finite, spatially localized set of interior actuators, with the feedback operator expressed through the Helmholtz projection and a Gram-matrix of actuator projections. The analysis introduces an extended shifted Stokes operator and decomposes the dynamics into reaction–convection and nonlinear terms, establishing weak solution existence and energy-based decay via a monotonicity property of the sum of the Stokes operator and the feedback. The main result shows that for sufficiently many actuators and large enough feedback gain, the closed-loop system achieves exponential decay with rate $\mu = \beta^{-1} \alpha$, and crucially, the decay rate can be made arbitrarily large by tightening boundary dynamics (as $\beta \to 0$). The framework accommodates several slip boundary types (Navier, vorticity-type, Neumann) and multi-connected domains, making the approach practically robust for a broad class of dynamic boundary control problems in fluid dynamics.
Abstract
Exponential stabilizability of the incompressible Navier-Stokes equations under dynamic slip boundary conditions toward arbitrary time-dependent trajectories is proven. The feedback control law is constructed explicitly using oblique projections and realized through a finite number of spatially localized interior actuators, without requiring spectral assumptions. The approach extends to various slip boundary condition types (Navier, vorticity-type, and Neumann) and applies to multi-connected domains. Weak solution existence and exponential decay estimates are established, with the stabilization rate depending on the boundary dynamics parameters.
