Active acoustic control of airfoil fluttering

By using the derived exact solution of the acoustically induced unsteady potential flow of a two-dimensional thin airfoil, the mechanism of flutter-suppression by active acoustic excitation, known as an extremely weak flow perturbation, was analyzed, the parametric effect of sound source on the flutter boundary was discussed, and through the theoretical calculation of the coupled acoustic-vortex, the experimental results obtained from the wind-tunnel testing were explained. The results show that in the acoustic flutter suppression process, there are certain relationships among the parameters of the closed-loop system, and the optimal parameter must be chosen reasonably. The present investigation provides a theoretical foundation for the active acoustic control techniques applied in the aerodynamic areas.