An experimental investigation of vortex flow control through small geometry modifications (fillets) at the strake/wing junction of a cropped, double-delta wing model with sharp leading edges was conducted in the Naval Postgraduate School Water Tunnel using the dye-injection technique. The effect of fillets was evaluated by focussing primarily onm the breakdown characteristics of strake vortices at high angles of attack (AOA) for both static and dynamic conditions of the models at zero sidesip angle. The dynamic conditions included a simple pitch-up and a simple pitch-down maneuver in the 0deg-50deg AOA range. The tests with each model highlight the vortex burst lag effect associated with dynamic motion, namely the delay/advance in strake vortex breakdown during pitch-uppitch-down motion. Comparison of test results for different fillet shapes indicates a clear trend in vortex burst delay at high AOA particularly for the diamond fillet shape. This vortex breakdown data implies lift augmentation for both the static and dynamic case, with the static data correlating well with the recently published numerical data.
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