We discuss the application of the reduced basis method for the simulation a
nd control of unsteady viscous flows governed by the incompressible Navier-
Stokes equations. We describe how to use this method in terms of the constr
uction of a lower-order compensator design. Our approach includes a constru
ction method of the optimal state feedback law for finite-dimensional nonli
near regulator problems. The method is applied to construct a feedback law
for the reduced order control model of the Navier-Stokes equations, and the
n we apply our feedback law to the original control system. Our method is d
emonstrated on a control problem formulated in a channel Row using a bounda
ry velocity control. We also show how these ideas can be extended to contro
l problems governed by partial differential equations. Numerical results ar
e reported for the open and closed loop controls, and a compensator design
is proposed to complete the closed loop dynamics. (C) 2001 Elsevier Science
Ltd. All rights reserved.