Distributed Conformal Actuation with Electroactive Polymer

Application of electroactive polymer (EAP) for flow control at the low Reynolds number values typical of Micro Air Vehicles is proposed. EAP offers (1) distributed actuation, (2) easy conformance to the shape of an airfoil, (3) high spatial and temporal bandwidths, and (4) the ability to both deliver and harvest energy from the flow field. Phase I included design, manufacture, and integration of EAP actuators into a wind tunnel test article. At appropriate frequencies a substantial reduction of the laminar separation bubble size was observed. Phase II will employ both experimental and computational efforts to identify EAP-based flow control strategies that result in desirable integral properties, i.e., maximal lift, lift-to-drag ratio and minimal drag. For our experiments stereo PIV measurements; static and dynamic surface pressure measurements; direct integral aerodynamic measurements; and flow visualization will be employed, whereas the computational efforts will rely on CFD simulation. In order to perform the experiments and demonstrate feasibility, we will undertake critical engineering issues: optimization of the EAP polymer, manufacture of EAP flow control actuators with spatially-selective control of the actuator cells, and demonstrate that electronics can meet the power and energy requirements within the very limited size and weight budgets of MAVs. BENEFIT: Distributed surface actuation with electro-active polymer for the purposes of managing the boundary layer can improve the range and endurance of proposed small UAVs and may ultimately represent a means to reduce drag and delay stall in commercial and military aircraft. Future applications for EAP distributed surface actuation include reduction in hydrodynamic drag on vessels, reduced frictional losses in pipes, and hull surfaces for improved stealth for ships and submarines.