Modern control of linear global instability in a cylinder wake model

This article investigates the implementation of modern control design techniques on models of open shear flows using the linear complex Ginzburg–Landau (GL) model for the cylinder wake, with the coefficients as scaled by Roussopoulos and Monkewitz (Physica D 97 (1996) 264). Based on noisy measurements 1.5 diameters downstream of the cylinder, the compensator uses an H ∞ filter to construct a state estimate which, in turn, is used to compute H ∞ feedback control at the cylinder to drive the system perturbations to zero. The application of such modern control rules leads to substantially better performance than the proportional measurement feedback proposed by previous studies. Preliminary results of the effectiveness of linear control to stabilize the nonlinear GL model are also presented.