Self-Activated Movable Flaps on Low Aspect Ratio Wings at Low Reynolds Numbers

Arivoli, D and Singh, Ishan (2015) Self-Activated Movable Flaps on Low Aspect Ratio Wings at Low Reynolds Numbers. In: International Micro Air Vehicle Conference and Flight Competition, Sept. 2015, Aachen, Germany.

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    Abstract

    Effectiveness of self-adaptive flaps in delaying flow separation on low aspect ratio wings of three different planforms were ascertained experimentally in a low speed wind tunnel at a Reynolds number of 105 based on their root chord. Flap widths between 0.08c and 0.15c; placement location between 0.4 x/c and 0.8 x/c were investigated. The flapped configurations exhibit good stall margin and higher CLmax in most cases. The chordwise placement location of adaptive flap for better lift enhancement varies with planform. Adaptive flaps placed at the maximum span location on a varying span planform exhibit better lift characteristics than flaps placed at other chordwise location. However, for a constant span planform like rectangle, chordwise location close to trailing edge seems to be optimal for flap placement. Full span flaps were efficient in obstructing the forward progression of reverse flow from stall vortex than part span flaps. The lift enhancing capabilities of double adaptive flapped configuration was relatively low compared to single adaptive flapped configuration. No detrimental effects were observed in the drag characteristics of the single flapped configurations of rectangular and inverse Zimmerman planform. However, significant drag increase was observed for the flapped configurations of Zimmerman model and double flapped configurations. The temporal behavior of the adaptive flap is aperiodic. Spectral analysis of the adaptive flap oscillation shows that it oscillates at multiple frequencies and the wing planform only influence the mean angle and magnitude of oscillation, while frequency of the oscillation seems to be flow dependent.

    Item Type: Conference or Workshop Item (Paper)
    Uncontrolled Keywords: Self-activated movable flaps;Low aspect ratio wings;Wind tunnel;Planform;Flight experiments
    Subjects: AERONAUTICS > Aeronautics (General)
    AERONAUTICS > Aerodynamics
    Division/Department: Experimental Aerodynamics Division, Other
    Depositing User: Ms. Alphones Mary
    Date Deposited: 15 Apr 2016 10:27
    Last Modified: 15 Apr 2016 10:27
    URI: http://nal-ir.nal.res.in/id/eprint/12452

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