Identifying the Onset of Buffet Boundary Using Sliding-Window Dynamic Mode Decomposition

Transonic buffet, characterized by shock-induced oscillations, presents a significant challenge to aircraft stability and performance. This study developed a sensor based on Dynamic Mode Decomposition (DMD) to predict buffet onset by analyzing the aerodynamic characteristics of the OAT15A airfoil under varying flow conditions, including different Mach numbers, Reynolds numbers, and angles of attack. The sensor was developed using data from a simulation at a Reynolds number of $3 \times 10^6$, a Mach number of 0.73, and an angle of attack of 3.35. The sliding-window DMD approach was employed to accurately identify the Strouhal number associated with buffeting and the transitions in flow stability, leading to the determination of the buffet onset boundary for different flow conditions. This boundary was subsequently used to validate the sensor, resulting in the development of a robust buffet detection tool. The sensor can be integrated into the design cycle to monitor and dynamically adjust parameters, thereby preempting buffet conditions.