Tail Buffet Alleviation of High-Performance Twin-Tail Aircraft Using Piezostack Actuators

Abstract

The phenomenon of the tail buffet is usually associated with high-angle-of-attack operations of a twin-tail aircraft. The unsteady pressures that result from the tail buffet, along with the aeroelastic coupling of the vertical tail structural assembly, cause vibrations of the empennage structural assembly. Such buffet-induced vibrations can shorten the fatigue life the empennage structure and limit the flight envelope of the aircraft due to the large amplitudes of the fin vibrations. Methods of alleviating the tail buffet-induced vibrations, by the use of smart structure concepts, is presented. Theoretical and experimental investigations were conducted to estimate and enhance the required control authority for tail buffet alleviation using piezoceramic-stack-based actuators. This was accomplished by designing an effective piezoelectric ceramic actuator assembly, developing procedures to place the sensors and actuators optimally on the vertical tail subassembly, designing controllers using acceleration feedback control concepts, and developing procedures to implement these controllers by using digital signal processor-based systems