Feedback control in spatially growing boundary layers

Authors: Chevalier, M.C., Hoepffner, J.P.J., Åkervik, E.Å., Henningson, D.S.H.
Document Type: Conference
Pubstate: Accepted
Journal: Laminar-Turbulent Transition, Proc. IUTAM Symp., Bangalore, Dec. 13-17. 2004. Ed. Rama Govindarajan, Springer,
Volume:    243-248
Year: 2006


Linear feedback control has been applied to transitional boundary layer flows. Information from wall-mounted sensors is used to estimate the flow state. The estimated state is then used to compute the optimal feedback control which is applied as blowing and suction with zero net mass-flux through the wall. The performance of the controller is tested in direct numerical simulations of a spatially growing Falkner--Skan--Cooke boundary layer where an inflectional instability is triggered. The extension to spatial boundary layer flows is an important step towards real applications.