Adaptive control method for frequency lock-in in transonic buffet flow

Transonic fluid-structure coupling control is a research branch that has attracted much attention in the field of aeroelastic research. However, due to the complexity of the frequency lock-in phenomenon coupling mode, research on fluid-structure coupling control methods in the chattering frequency-locked state is still relatively rare. Considering that the frequency-locked state in chattering is essentially the instability of the flow mode and the structural mode, it is difficult to suppress it by a single control law. Therefore, a model-free adaptive control method with multiple feedback loops is proposed. By introducing structural displacement and aerodynamic response data, combined with a model-free adaptive control method, the closed-loop control study under the simulation state of the fluid-structure coupling model at the typical buffeting state of 0.7 Mach and 5.5° angle of attack is carried out. The results show that by introducing structure and aerodynamic response as control parameters, the frequency-locking instability mode can be effectively suppressed, and by switching the control mode, the airfoil flow and structural instability in the frequency-locking state can be controlled.