Measurement of leading and trailing edge vortex shedding mechanism for flapping airfoil in hover using particle image velocimetry technique

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Bilimleri Enstitüsü, Fen Bilimleri Enstitüsü, Türkiye

Tezin Onay Tarihi: 2013

Öğrenci: AYBÜGE ÇEKİNMEZ

Danışman: HÜSEYİN NAFİZ ALEMDAROĞLU

Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu

Özet:

In this thesis, the vortex shedding formation/mechanism for flapping airfoil making the figure of eight motion in hover is investigated experimentally using Particle Image Velocimetry (PIV) technique and numerically for some parameters determined. For this investigation, a new flapping mechanism is designed and implemented to the existing water tank, where the airfoil is traversed laterally, such that the motion depicts a figure of eight. The traversing system is moved both in x (horizontal) and y (vertical) directions such that the figure of eight is drawn. This is the type of flapping motion for some of the birds in nature. The amplitude and the frequency of oscillations can easily be adjusted. The PIV technique is used to put into evidence the vortex shedding mechanism from the leading and trailing edges of the airfoil. Experiments are performed to investigate the effects of the parameters which are the amplitude of the figure of eight flapping motion, initial angle of attack, and the shape of the airfoil. From these experiments, the unsteady behavior of the vortices shed from the airfoil is analyzed and their effect on the generation of lift and drag is investigated. Also, the numerical study performed for the some parameters in present and previously done by Başkan [10] is supported and completed by this experimental study.