Control of a separated boundary layer: reduced-order modeling using global modes revisited.

Ehrenstein, Uwe; Passaggia, Pierre-Yves; Gallaire, Franois

The possibility of model reduction using global modes is readdressed, aiming at the controlling of a globally unstable separation bubble induced by a bump geometry. A combined oblique and orthogonal projection approach is proposed to design an estimator and controller in a Riccati-type feedback setting. An input-output criterion is used to appropriately select the modes of the projection basis. The full-state linear instability dynamics is shown to be successfully controlled by the feedback coupling with controllers of moderate degrees of freedom.

BOUNDARY layer control; OBLIQUE projection; ORTHOGRAPHIC projection; NUMERICAL solutions to Riccati equation; EIGENVALUES; EIGENVECTORS; REYNOLDS number

Theoretical & Computational Fluid Dynamics, 2011, Vol 25, Issue 1-4, p195

0935-4964

Academic Journal

10.1007/s00162-010-0195-5