Vortex breakdown from a pitching delta wing incident upon a plate: Flow structure as the origin of buffet loading

A delta wing is subjected to both static and dynamic variations of angle-of-attack; the vortices from the wing impinge upon a stationary plate. A technique of high-image-density particle image velocimetry is employed to compare the patterns of vortex development with and without the impingement plate. For the limiting case of static variations of angle-of-attack, the presence of the plate exerts a large influence on the onset of vortex breakdown. In contrast, dynamic (unsteady) variation of angle-of-attack yields changes of breakdown location that are generally similar for cases with and without the impingement plate. The detailed structure of the vortex breakdown-plate interaction is represented by patterns of instantaneous velocity and vorticity, which serve as the origin of buffet-induced loading of the surface of the plate. © 2002 Elsevier Science Ltd. All rights reserved