Control of Vortex-Induced Turbulent Flow by Curved Perforated Plate

Öz

In this study, the control of the vortex-induced turbulent flow in the wake of a circular cylinder was investigated using curved perforated plate (control element) having various and partial porosities. PIV measurements were performed for the considered parameter ranges, Reynolds shear stresses were calculated in the flow field and the contour distributions of the bare cylinder and controlled cases were compared quantitatively. According to the results, it was understood that the Reynolds numbers had identical effects on the flow control. However, it was observed that the shear stresses in the cylinder wake decreased for all examined cases of porosity and arc angle. It has been revealed that the maximum value of Reynolds shear stress is decreased by 96% compared with the bare cylinder and the unsteady flow in the cylinder wake is completely controlled at 120o≤ α ≤180o for β = 0.5 and β = 0.6.

Anahtar Kelimeler

• Flow control
• Unsteady flow
• Vortex shedding
• Bluff body
• PIV

Kavisli Delikli Plaka ile Girdap Kaynaklı Türbülanslı Akışın Kontrolü

Öz

Bu çalışmada, dairesel bir silindir art izinde oluşan girdap kaynaklı türbülanslı akışın, farklı ve kısmi geçirgenlik oranlarına sahip kavisli delikli plaka (kontrol elemanı) ile kontrolü incelenmiştir. Ele alınan parametre aralıklarında PIV ile hız ölçümleri yapılmış, akış alanında Reynolds kayma gerilmeleri hesaplanmış ve kontrol durumu ile yalın silindir durumunun kontur dağılımları nicel olarak karşılaştırılmıştır. Elde edilen sonuçlara göre, ele alınan Reynolds sayılarının akış kontrolüne benzer oranda etki ettiği anlaşılmıştır. Bununla birlikte, incelenen tüm geçirgenlik oranları ve yay açıları için silindir art izinde oluşan kayma gerilmelerinin azaldığı görülmüştür. 120o≤ α ≤180o yay açılarında ve β=0,5 ve β =0,6 geçirgenlik oranlarında, yalın silindire kıyasla maksimum Reynolds kayma gerilmelerinin %96’ya kadar düştüğü ve silindir art izindeki daimi olmayan akışın tamamen kontrol edildiği ortaya çıkarılmıştır.

Anahtar Kelimeler

• Akış kontrol
• Daimi olmayan akış
• Girdap kopması
• Küt cisim
• PIV

Kaynakça

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