Kentucky NASA EPSCoR: Development and Testing of Enabling Technologies for Morphing Airfoils with Inflatable Structures

The development of enabling technologies for morphing airfoils for low speed/low density conditions (low Reynolds number) is proposed. Conventional airfoils use heavy actuators such as flaps and slats for lift improvement at low speeds. Such devices are inadequate in low density atmospheres, such as high altitude flight in Earth's atmosphere or any altitude in the atmosphere of Mars. Weight reduction, propulsion costs and reasonable relative ground speeds of aircraft in such low density environments will drive the available dynamic pressures down substantially requiring a corresponding increase in lift. With current common state airfoils the necessary lift coefficients are unattainable, particularly since at low densities the Reynolds numbers are driven to values at which the assumptions underlying conventional wing theories do not hold. The effects of viscosity do not remain confined to a thin boundary layer, and large separation regions occur destroying the performance of conventional airfoils. We propose the development of low Reynolds morphing airfoils that have the ability to alter their shape in situ to maximize their lift and for enhancement in maneuverability. One technology that shows promise in meeting these goals is inflatable wing sections with embedded actuators that can rapidly alter wing shape. We have thus far demonstrated the effectiveness of particular techniques of the latter in reducing the degree of separation overflow speed airfoils. This proposal will explore the optimization of the shape controlling parameters and shape tailoring processes of morphing airfoils through both modeling and experimental investigation, name prediction and measurement of aircraft performance variations during morphing maneuvers, as well as morphing strategies that achieve maximum performance enhancement with minimal shape changes. The outcomes of the project will include (but not be limited to) (i) trade studies of morphing strategies, (ii)development and laboratory tests of enabling morphing technologies, (iii) formulation of a morphing control strategy and shape prediction methodology, and (iv) wind tunnel and flight testing of the most promising of these technologies. The course and outcomes of the project will be closely directed with the needs of NASA in mind as determined by the NASA collaborators.