Transonic flutter suppression using active acoustic excitations

The objective of this work is to study the feasibility of using acoustic waves as a means for suppressing the flutter instability of a typical section in transonic flow. A high-resolution upwind TVD flow solver of acoustic accuracy was first constructed and validated on a dynamic mesh system. The geometric conservation law was implemented consistently with the physical conservation law via a suitably defined cell boundary speed. This specially developed structure/fluid/acoustic solver was then integrated in the time domain to study whether flutter can be suppressed using active acoustic excitations. Flutter suppression was achieved in the transonic region when an appropriate feedback control law was used. Large-amplitude limit cycle type oscillation in a transonic flow was also simulated. It was found that the present acoustic control technique can only be effective when the amplitude of the oscillation is small in accordance with previous findings obtained in a low-speed wind-tunnel test.