A Dynamic Observer to Capture and Control Perturbation Energy in Noise Amplifier Flows

In this article, we present a technique to extract a reduced-order model of a transitional flat-plate boundary layer from simultaneous velocity snapshots and wall-shear stress measurements. The proposed approach combines a reduction of the degrees of freedom of the system by a projection of the velocity snapshots onto a POD basis together with a system-identification technique to obtain a state-space model of the flow. Such a model is then used in an optimal control framework to reduce the kinetic energy of the perturbation field and therefore delay transition.