The wake alleviation properties of triangular-flapped wings are estimated by comparing the rolling moment and downwash in the wakes of the triangular-flapped wings with those in the wake of a baseline-rectangular wing. Using planar PIV velocity field data, the rolling moment and downwash are calculated over a simulated following wing, which has a span half that of the wings. For the unmodified, rectangular wing the trailing vortex wake is stable, two-dimensional, and long-lived, resulting in a rolling moment and downwash that exhibit minimal decay over the time of measurements. On the other hand, the triangular-flapped wings generate a trailing vortex wake that has significant wake alleviation properties. The triangular-shaped flap produce oppositely signed flap vortices near the tip vortices, resulting in a vortex wake comprised of two unequal strength, counter-rotating vortex pairs. Within 15-20 spans these vortex pairs undergo a rapidly growing sinuous instability that transforms the two-dimensional nature of the wake into a three-dimensional one. The resulting distributions of rolling moment and downwash are shown to be highly diffuse when compared to those in the wake of the rectangular wing. Furthermore, both the maximum rolling moment and downwash are approximately one-half the average value for the rectangular wing by 75 spans. This behavior is seen to exist for all of the experimental runs over which the counter-rotating flap vortices have strengths ranging from 40 to 70% of that of the tip vortices. The results demonstrate that the instability in the wake off the triangular-flapped wings offers a possible mechanism for rapid and effective wake alleviation.


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    Titel :

    Wake alleviation properties of triangular-flapped wings


    Weitere Titelangaben:

    Verringerung der Reichweite von Wirbelröhren im Nachstrom von Tragflächen durch dreieckige Landeklappen


    Beteiligte:
    Ortega, J.M. (Autor:in) / Bristol, R.L. (Autor:in) / Savas, Ö. (Autor:in)

    Erschienen in:

    AIAA Journal ; 40 , 4 ; 709-721


    Erscheinungsdatum :

    2002


    Format / Umfang :

    13 Seiten, 16 Bilder, 1 Tabelle, 30 Quellen




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Print


    Sprache :

    Englisch