Wake Vortex Alleviation Flow Field Studies

Airplane trailing vortices and their control

“…Several studies have considered the unforced development of a two-pair system, with counter-rotating vortices on each side of the airplane [4,[13][14][15][16]21]. When forced, this system can lead to enhanced breakup of the vortices as discussed in the previous section.…”

“…The relative coherence of the vortices, as measured by a 'pseudo-two-dimensional kinetic energy', is reduced as a result of the instability development. The results of Durston et al [4] suggest that the net result of the unforced counter-rotating pair is an altered pair of vortices, which might be characterized by waviness, an enlarged core, and/or some form of streamwise periodic distortion of the cores. The basic strength and centroid positions of the resulting vortices can usually be estimated from the near wake, without regard for the instabilities.…”

“…Most configurations will generally not have excess lift that can be forfeited over the inboard wing. When tail vortices are used to generate the counter-rotating pair, Durston et al [4] have shown that the center-of-gravity position for the airplane is highly constrained.…”

Active and passive vortex wake mitigation using control surfaces

“…All configurations are found in a narrow region in the lower periodic regime that can be approximated by Eq. (9).…”

“…Towing tank experiments conducted at the German Aerospace Centre [8] and flow field studies of Durston et al [9] investigate wing/tail configurations. The vortex system consists of the tip vortex pairs of the wing and the tail.…”