NASA has long been recognized as a leader in aeronautics research and development that has greatly contributed to aircraft technology for safe and efficient air travel. A new focus is emerging in “green” aviation technologies that could potentially revolutionize aviation systems. One potential green aviation technology interest is in active wing shape control that holds the promise for improved aerodynamic efficiency. The structural flexibility of aircraft wings can afford a number of advantages that are not yet fully realized. One such advantage is the ability to aeroelastically shape a wing structure in flight by actively controlling the wash-out twist distribution and wing deflection, so as to effect local angles of attack in a favorable manner that can lead to lower drag and higher lift. Another advantage is the ability to leverage aeroelastic wing shape tailoring for improving aircraft stability and control. Development in green aviation technologies will lead to improved aerodynamic efficiency, lower emissions, less fuel burn, reduced noise, and a minimized carbon footprint.
What is NASA Doing?
NASA is conducting system-level research to enable transition of foundational technologies into aviation systems or subsystems. At the foundational level, relative to active wing shape control, computational modeling at various levels of fidelity is being developed to understand complex modes of interaction among aerodynamics, aircraft dynamics, and structural flexibility. Advanced flight control as an enabling technology to handle these complex modes of interaction is being developed.
What Are NASA’s Needs?
NASA is actively seeking partners to conduct crosscutting technology development from conceptualization to technology demonstration of active wing shape control. Areas of technology needs are:
Sensor technology. This technology explores new concepts of sensor development for accurately measuring wing in-flight deflection due to combined bending and torsion moments resulting from aerodynamic forces and moments. New sensors should be able to measure both static and dynamic components of the wing deflection. The sensor bandwidth should be sufficiently fast to enable sensors to be used for providing data to an active wing shape control system.
Actuation technology. This technology examines novel modes and types of actuation for actively controlling wing shape in flight. In order to provide enough control forces and moments, new actuators need to be developed along with feasibility studies of effective placements of new control effectors on a wing structure. The actuator bandwidth should be sufficiently fast to enable an active wing shape control system to perform its function with a negligible phase delay.
Integrated flight-structural control technology. Novel, integrated approaches for controlling flexible aircraft structures need to be developed for active wing shape control technology. NASA welcomes knowledge capabilities of incorporating structural control into an existing flight control system. Structural safety always takes priority; therefore, active wing shape control approaches need to be able to effectively manage performance objectives within a confine of structural safety imposed by airframe load limits and structural mode interactions with a flight control system.