On the interaction between a leading edge vortex and Active Flow Control on a swept wing

Swept back thin wings used on combat aircraft rely on vortices to augment their lift and provide added control to their control surfaces. However, much of the previous research on active flow control (AFC) focused on the maintenance of attached flow or the forced re-attachment of separated shear layers. Redirection and control of the leading edge vortex (LEV) may also lead to significant improvements in aircraft efficiency and maneuverability. In this study, flow interactions between the LEV and sweeping jet actuators located downstream are investigated in a subsonic wind tunnel on a highly configurable swept wing model. Balance measurements and surface tuft visualizations demonstrated that the formation and propagation of the LEV directly impact AFC efficacy downstream across a wide range of geometric configurations. In turn, AFC can also influence the upstream LEV dynamics through global changes in pressure and velocity fields. Detailed understanding of these interaction mechanisms is crucial for effective exploitation of AFC technology on swept wing aircraft. Future aircraft designs should incorporate AFC into the early conceptual stages so that it can optimally interact with both attached and vortex flows.