Large-Area Aerodynamic Control for High-Altitude Long- Endurance Sensor Platforms

The use of large-area aerodynamic control schemes to enable high-altitude long-endurance sensor platforms is investigated. The focus is on a vehicle with a joined-wing design. The vehicle has two performance shortcomings that are considered typical of the broader class of high-altitude long-endurance vehicles. The first is minimum roll rate at landing due to the large amount of roll damping associated with these configurations. It is shown that multiple distributed control surfaces can help meet the roll rate requirements. The second is sensitivity of takeoff gross weight to maximum lift-to-drag ratio. Notional mission requirements drive the fuel fraction to high levels and small changes in lift-to-drag ratio can enable large changes in the vehicle weight through reduced fuel requirements. It is shown that the same technology used to satisfy the roll requirement can also be used to actively control the twist and camber during cruise and can have a moderate impact on the vehicle weight or endurance.