Silindir Art İzindeki Daimi Olmayan Girdapların Kılavuz Plakalar Yardımı ile Bastırılması

Öz

Dairesel kesitli silindirin art izindeki daimi olmayan girdapların kılavuz plakalar kullanılarak bastırılması deneysel olarak araştırılmıştır. Kılavuz plakalar yay şeklinde imal edilmiş ve üç farklı açıklık oranı (G/D=0,1, 0,3 ve 0,5) ve plaka açı değerleri 60°≤α≤90° aralığında incelenmiştir. Silindir art izindeki akış yapıları PIV ölçümü ile Reynolds sayısının 7500 değerinde elde edilmiştir. Akış ölçümünden elde edilen Reynolds kayma gerilmeleri, girdap konturları, hız bileşenleri ve girdap kopması frekans sonuçları ile yalın silindir durumu ile kıyaslanarak açıklanmıştır. Düşük plaka açı değerlerinde girdap kopma frekansları üzerinde daha etkin olduğu yüksek plaka açı değerlerinin ise girdap sönümlemede daha etkin olduğu gözlemlenmiştir. Reynolds kayma gerilmelerinin bastırılmasında açılık oranı G/D=0,1’in diğer açıklık oranları ile kıyaslandığında daha etkili olduğu gözlemlenmiştir.

Anahtar Kelimeler

• Pasif akış kontrol
• Girdapların bastırılması
• PIV
• Silindir

Vortex Suppression Downstream of a Cylinder via Guide Wanes

Öz

It is experimentally investigated that vortex suppression of the circular cylinder in the wake region by guide wanes. Three distinct gap ratios (G/D=0.1, 0.3, and 0.5) and plate angle values in the range of 60°–90° were examined for the guide wanes, which were fabricated in arc form. Flow structures of the cylinder in the wake region were obtained by PIV measurement at Reynolds number of Re=7500. The obtained results such as Reynolds shear stress, velocity components, vortex contours, and vortex shedding frequency are explained in comparison with the bare cylinder. It was observed that low plate angle values are more effective on the vortex shedding frequencies, and higher plate angle values are more effective on vortex suppression. It was observed that the gap ratio of G/D=0.1 is more effective on suppression of Reynolds shear stresses when compared to the other gap ratios.

Anahtar Kelimeler

• Passive flow control
• Suppression of vortex
• PIV
• Cylinder

Kaynakça

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