Distributed Conformal Actuation with Electroactive Polymer

Application of electro-active polymer (EAP) to critical aerodynamic surfaces of Micro Air Vehicles (MAVs) is proposed, in order to manage the boundary layer. EAP offers a means to achieve distributed actuation and can be readily conformed to the shape of an airfoil. At low Reynolds number-flight, typical of MAVs, the intent is (1) to promote transition to turbulence, where laminar separation would otherwise occur, and (2) to maintain laminar flow, where separation is not an issue. In Phase I, requirements for frequency, amplitude, and spatial character of the perturbations to the nominal airfoil shape will be established, including dynamic roughness (high spatial and temporal frequencies) and camber control (low spatial and temporal frequencies). EAP layers will be designed, manufactured and applied to a representative test airfoil. Bench tests will verify the capability of the airfoil to meet requirements, and indicate design improvements. Wind tunnel tests will also be conducted on the airfoil with EAP, in order to demonstrate the ability of the EAP to affect flow in a controlled manner. In Phase II, EAP would be applied to airfoils with compound curvature and with large and time-varying pressure gradients, and the benefits would be measured in a wind tunnel.