Design and Characterization of Novel Piezoceramic C-Block Actuators for a Balanced Active Flap System

Abstract : In this research, a high authority piezoceramic actuation technology was developed to drive an active flap system with less sensitivity to gust loads and little to no degradation in performance with increasing rotor speed. This research effort took a new approach to active flap control through the usage of C-blocks, a promising actuator architecture with midrange performance, high efficiency, and a tailorable architecture. When applied to rotorcraft, this system has potential to reduce vibration levels and yield better handling and overall performance. This system is also beneficial for fixed wing applications such as munitions guidance and UAV control. The two primary tasks of this research were: (a) to design and characterize piezoceramic C-block actuators, and (b) to develop and wind tunnel test an aerodynamically and mass balanced active rotor blade flap incorporating C-block actuators. Through analytical modeling and experimental validation over a broad design range, this research has established the foundation to apply this actuation technology to a wide range of applications. As a demonstration of the actuator's high authority and the benefits of impedance tailoring, the actuators were integrated into a NACA 0012 airfoil with a 10% flap and generated high flap deflections with no significant sensitivity to airspeed.