Active Flow Control Applications to High-Lift Leading-Edge Devices

Active flow control was applied to the leading-edge region of a representative future short/medium-range twin-engine airplane to improve aerodynamic performance during high-lift operations. The study was aimed at enhanced lift over the practical angle-of-attack range, including stall, and at reduced drag. These benefits translate to airplane performance improvements, such as longer range or larger payload. Various flow control applications were explored using computational fluid dynamics by targeting control of bounded viscous layers and vortex flows. The computational analyses were used to quantify aerodynamic benefits, as well as the input required for actuation. The results were used in a system integration study for identifying potential practical implementations, which are described in a companion paper. Combined with the integration analysis, the objective of this project is to identify the most promising flow control candidates that potentially provide material net airplane level enhancements using onboard fluidic sources. Depending on the implementation of active flow control, the current study indicates that up to 1.5% net improvement in lift-to-drag ratio at takeoff and 4% increase in maximum lift during landing are potentially achievable, after accounting for factors of system integration.