"Visualization of Rate Dependent Vortex Phenomena During Aircraft Maneuvers"
John C. Magill, Leigh Ann Darden, Narayanan M. Komerath

AIAA Paper 94-0669, January 1994

ABSTRACT
Vortex flow interactions occurring near the vertical fins of a modern fighter configuration during pitch, yaw, and coupled pitch-yaw motions are explored. Such motions are produced using a two-degree-of-freedom Wind-Driven Dynamic Manipulator, under open loop radio control in a low-speed wind tunnel. Laser sheet videography is used to capture the flow features, which are then extracted by analyzing sequences of digitized video on a computer. Selected pitch maneuver sequences are analyzed to examine rate effects on vortex trajectory. Large asymmetry and complex interactions are observed in the flowfield. Vortices generated by the forebody, wing leading edge, wing tip, and vertical fins are seen to interact during the coupled pitch-yaw maneuver. However, no significant rate effects were seen in the vortex locations at the trailing edge plane for reduced frequencies up to 0.36 based on wing span.

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