On the Fluid Dynamics of Adaptive Airfoils

This paper discusses issues and practical requirements for an adaptive wing in relation to currently available technology. Adaptive wings offer many benefits, but a viable wing will require research into several areas, including selection of initial and perturbed airfoil shapes, steady and unsteady aerodynamic analysis of adaptive airfoils, and methods for real-time shape control of an adaptive wing system. An overview of adaptive wing history is briefly covered, including some recent developments. Development considerations for an adaptive wing system are then discussed. Aerodynamic performance and stability should be considered in the context of the wing’s structural integrity and aeroelasticity. Particular attention should be paid to the unsteady nature of the flow, as standard quasi-steady flow analysis techniques should be abandoned due to the rapid changes in wing shape and motion. Due to the large number of variable and measured parameters, an advanced control system is required to relate the flight conditions with changes in geometry. Issues related to adapting wings to various aircraft scales will be discussed, specifically micro aerial vehicles (μAVs), unmanned aerial vehicles (UAVs or RPVs), full-scale aircraft, and ornithopters.