Control of High-Incidence Vortical Flow on Double-Delta Wings Undergoing Sideslip

Abstract

An experimental study of the vortical flow over a baseline double-delta wing model and a diamond-fillet double-delta wing model, both with sharp leading edges, was conducted in a water tunnel using the dye-injection technique at a nominal flow Reynolds number of 1.875 x 10 4 . The diamond fillets at the strake/wing junction increased the wing area of the baseline model by 1%. The main focus of this study was to evaluate the effect of juncture fillets on the vortex core trajectory and the vortex burst location at high angles of attack with sideslip angle. Comparison of the test results between the baseline and the diamond-fillet models indicates a clear delay for the latter model in terms of both the vortex core trajectory, and the breakdown location at high angle of attack, with sideslip angles. The vortex breakdown data for the diamond-fillet model implies lift augmentation during sideslip motion, thus supporting the concept of flow control using fillets. From the maneuvering viewpoint, the data suggest that the diamond-fillet model has a better operational envelope.