Magnetostictively-Actuated Flaperon to increase rotor thrust

Progress in electric flight control has been hindered by the lack of a high bandwidth actuator. The challenge is to identify an efficient, responsive, and powerdense source of mechanical displacement. Actuators based on "giant" magnetostrictive materials, such as Terfenol, achieve very high magnetic strain (up to 2,000 ppm) and therefore provide power density unmatched in electromechanical systems. They outperform all known piezoelectric materials in terms of mechanical properties. SatCon has used Terfenol in several high performance actuators for space applications. In a large-stroke actuator, however, strain must be amplified while preserving power density. SatCon proposes to demonstrate an innovative actuator which uses local hydraulics to transform magnetostrictive strain into an arbitrarily long stroke. Magnetostriction generates pressurized fluid flow which powers a linear hydraulic actuator. The benefits of high performance hydraulics are retained without sacrificing the weight, redundancy, reliability, and simplicity of electric actuation. During Phase I, SatCon will develop a preliminary actuator design suitable for a cyclic/collective application. During Phase II, SatCon will detail design, fabricate, and bench test the actuator. Specifications will be as stated (3 inch stroke, 25 hp rating, and a reponse comparable to hydraulics). Alternate forms of electric power will be studied. Air cooling will be maximized.