Controlling chaotic motions in a two-dimensional airfoil using time-delayed feedback

In this paper, the chaotic motions of a two-dimensional airfoil are controlled by the application of the time-delayed continuous feedback method of Pyragas. The airfoil has cubic pitching stiffness and linear viscous damping when kept in an incompressible fluid flow. Four control strategies are implemented with plunging displacement, plunging velocity, pitching angle, and pitching velocity as the feedback signals. The control signal is applied to perturb the airspeed parameter. The response of the system under these four controls is compared. It is found that the feedback control signal derived from the pitching variables was found to be more effective in controlling the chaotic motion of the airfoil.