The three-dimensional tip vortex flow behind an untwisted, sweptback and tapered NACA 0015 wing with and without winglet was investigated. For a baseline wing, the inner-region of tip vortex was nearly axisymmetric for x/c_r > 0.625 and always exhibited a self-similar behaviour. Although the winglet introduced a secondary junction vortex, in general it produced favourable deviations in the vortex properties with reduction in C_(Di) ranging between 46-83%. Moreover, the winglet with anhedral was more effective compared to that with dihedral. Note, however, that the winglet geometry is undoubtedly not optimum and that the documentation of the turbulence structure is needed to supplement the mean flow data.
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