Input-output analysis, model reduction and control of the flat-plate boundary layer

Authors: Bagheri, S., Brandt, L.B., Henningson, D.S.H.
Document Type: Article
Pubstate: Published
Journal: J. Fluid Mech.
Volume: 620   263-298
Year: 2009


The dynamics and control of two-dimensional disturbances in the spatially evolving boundary layer on a flat-plate are investigated from an input-output viewpoint. From the linearized Navier–Stokes equations with inputs (disturbances and actuators) and outputs (objective function and sensor) controllable, observable and balanced modes are extracted using the snapshot-method and a matrix-free time-stepper approach. A balanced reduced-order model is constructed and shown to capture the input-output behavior of linearized Navier–Stokes equations. This model is finally used to design a H2-feedback controller to suppress the growth of two-dimensional perturbations inside the boundary-layer.