High Angle of Attack Aerodynamics of Excitation of the Locked Leeside Vortex

The control of flow over a multi-component wing at large incidence has been investigated. At large incidence angles flow over, the wing upper surface becomes fully separated. The wing geometry was considered critical in management of flow energy through organization of vorticity and controlling its shedding on the wing upper surface. A flat plate wing, with the planform of a F-15 wing, was reconfigured to accommodate the locked vortex. Span-wise blowing was used to initiate and/or to increase the strength of the vortical flow. It was anticipated that in this manner an excited, stable, concentrated and strong vortex would be created on the wing. Using flow visualization as well as force measurements it was found that the presence of the locked vortex favorably changed the flow pattern over the wing. Force measurements indicated moderate improvements on most configurations. One configuration, however, demonstrated significant improvements. Improved results are preliminary; however, they may be of tremendous potential.