Adaptive Feedback Flow Control for Wings

We present an adaptive flow control strategy for a turbulent separated flow using online dynamic mode decomposition. The system dynamics are identified in real time, and a linear quadratic tracking controller regulates the separation location along a predefined target. Controller gains are updated continuously based on the new system updates, allowing for an adaptive formulation of real-time feedback control that can adjust to both variations in the freestream flow due to external disturbances and actuation-induced changes of the flow dynamics. The approach is demonstrated on a NACA4412 wing at [Formula: see text] using direct numerical simulation at 0 and 10 deg angles of attack, outperforming steady blowing in moving the separation point downstream. At 10 deg, adaptive control increases lift to drag by approximately 60%. The framework is further extended to directly regulate the lift-to-drag ratio, illustrating its potential for real-time control of aerodynamic forces in unsteady, separated flows.