NUMERICAL INVESTIGATION OF HEAT AND FLOW CHARACTERISTICS CONTINUOUS LAMINAR CHANNEL FLOW WITH HIGH BLOCKAGE AROUND TWO TANDEM CIRCULAR CYLINDERS

Yıl 2015, Cilt: 56 Sayı: 667, 53 - 63, 02.08.2015

Neslihan Güneş , Alper Özalp

Öz

In this study, heat and flow characteristics of laminar steady flow across two tandem circular cylinders (CC) were numerically investigated. The blockage ratio (β=B/H) were held 0.6 and the Reynolds number (Re) was 40. The distance between circular cylinders were chosen 0.2-0.7-1.0-1.5-3.0-4.0 D and static pressure, shear stress and heat transfer coefficients on the upstream (front) and downstream (back) cylinders were calculated and discussed. Otherwise the results that were obtained for two tandem cylinders were compared with the results that were obtained for single cylinder for the same scenarios. According to the calculations it is understood that wakes and vortices between cylinders directly affect hydrodynamic and thermal parameters. Separations of the flow around the cylinder also effect on shear stress and convective heat transfer values.

Anahtar Kelimeler

Blockage ratio, distance between cylinders

YÜKSEK BLOKAJLI KANAL İÇİNDE ART ARDA İKİ SİLİNDİR ETRAFINDA SÜREKLİ LAMİNER AKIŞ İÇİN ISI VE AKIŞ KARAKTERİSTİKLERİNİN NÜMERİK OLARAK İNCELENMESİ

Öz

Bu çalışmada, art arda silindirler etrafında yüksek blokaj etkisinde laminer akış için ısı ve akış karakteristikleri nümerik olarak incelenmiştir. Blokaj oranı (β=B/H) 0.6 ve Reynolds sayısı (Re) 40 olarak belirlenmiştir. Silindirler arası mesafe sabit silindir çapı ile orantılı olarak 0.2-0.7-1.0-1.5-3.0-4.0 D olarak seçilmiştir. Ön ve arka silindirler için tüm silindirler arası mesafe oranlarında statik basınç, kayma gerilmesi ve ısı transfer katsayıları değerleri hesaplanıp tartışılmıştır. Ayrıca çift silindir için elde edilen sonuçlar, aynı senaryolar tek silindir için elde edilen sonuçlar ile karşılaştırılmıştır. Hesaplama sonuçlarına göre akım çizgi ve vortekslerin direk olarak hidrodinamik ve termal parametreleri etkilediği anlaşılmıştır. Silindir etrafındaki ayrılmalar ise kayma gerilmesi ve ısı transferi değerlerini etkilemiştir.

Anahtar Kelimeler

Blokaj oranı, silindirler arası mesafe

Kaynakça

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