Flow control of a turbulent separation bubble: Information-theoretic approach*

Turbulent separation bubbles (TSBs) may form over aerodynamic surfaces under the influence of adverse pressure gradients, significantly impacting aerodynamic efficiency. Thus, minimizing these bubbles is crucial for enhancing the performance and reliability of aircraft. We investigate the effectiveness of a zero-net-mass-flux (ZNMF) control strategy for a TSB within an information-theoretic framework (IT-control). The control problem is framed in information-theoretic terms by envisioning the tandem sensor-actuator as a device that reduces the unknown information about the state to be controlled. By leveraging the information-theoretic formulation, we determine the optimal (1) locations of sensors, (2) locations of actuators, and (3) actuator parameters that minimize the error between the actual and desired probability distributions of the recirculation length of the turbulent bubble. The IT-control approach is compared to other ZNMF controllers.