Preliminary Design of Hydraulic and Pneumatic System Architectures for a Morphing Flight Control Structure

Bionics in aeronautics has the potential to increase the performance and efficiency of aircraft significantly. Inspired by the wings of birds, morphing wing structures have been extensively investigated over the last decades. The continuous adaption of the wings over a large scale of the flight envelope enables an optimization of the aerodynamic characteristics and, this way, a reduction of the fuel consumption. Additionally, those structures could support or replace traditional flight control surfaces. Depending on the morphing technology, different systems may be suitable to actuate the morphing structure. An early inclusion of the system architecture into the development of the morphing technology enables designing an optimal system in compliance with all requirements. Therefore, this paper discusses the conceptual design of system architectures for a novel morphing wing structure that is used for flight control. The benefits of morphing structures for aircraft applications are shown and the functionality of the used morphing structure is introduced. The morphing structure was designed to be actuated by fluids and is compatible with different gases and liquids. Since the fluid has a significant effect on the system architecture, characteristics of hydraulic and pneumatic systems were examined. Based on the requirements of the morphing structure, different system architectures were developed. Following, hydraulic and pneumatic architectures were selected for further investigations. Sizing functions for all main components, such as hydraulic pumps and electric motors, are presented. The preliminary design of the pneumatic system was additionally supported by a dynamic simulation. Finally, an evaluation of the selected architectures was conducted.