Induced-Strain Actuators for Morphing of Multi-Element Airfoils

A multi-objective optimization framework is developed to examine the capabilities of surface-mounted piezocomposites for camber morphing of multi-element airfoils for various sizes of aircraft. A parameterized piezocomposite-actuated airfoil concept, along with associated modeling and analysis methods, is presented for determining the static aeroelastic response of a morphing multi-element airfoil. The optimization algorithm is also presented for determining airfoil parameters for meeting an arbitrary mission objective. The optimization capability is demonstrated using a multi-element airfoil to produce high-lift control surface geometries. A model-scale prototype is designed based on the optimization and fabricated for experimental testing to validate the design framework and provide confidence for full-scale analysis. Full-scale morphing capability is examined using commercially available piezocomposite actuators for a small passenger jet, clearly quantifying the limitations of induced-strain actuation at large aerodynamic loading and Reynolds numbers. Additional design optimizations are conducted and presented with a so-called “vision” actuator that is not available today; however, it may become available in the future. It is shown that strain-induced actuation for large aircraft may become reality in the future with reasonable developments in smart materials.