Jet Giriş Genişliğinin Isı Transferi ve Akış Yapısına Olan Etkisinin Araştırılması

Öz

Bu çalışmada, farklı jet giriş genişliklerindeki kanallarda bulunan düz yamuk ve ters yarım daire şeklinde iki farklı desene sahip bakır plakalı yüzeylerden hava jeti akışı ile olan ısı transferi sayısal olarak araştırılmıştır. Sayısal hesaplamalar, zamandan bağımsız ve üç boyutlu olarak enerji ve Navier-Stokes denklemlerinin k-ε türbülans modelli Ansys-Fluent bilgisayar programı kullanılarak çözülmesiyle gerçekleştirilmiştir. Kanalların üst ve alt yüzeyleri adyabatik olup desenli yüzeylere sabit ısı akısı uygulanmıştır. Jet giriş genişlikleri Dh ve 1,25Dh’dır. Çalışmanın sonuçları, literatürdeki çalışmanın sayısal ve deneysel sonuçlarıyla karşılaştırılmış ve birbirleriyle uyumlu oldukları görülmüştür. Sonuçlar, her bir desenli yüzey için ortalama Nu sayısı ve yüzey sıcaklık değişimi olarak sunulmuştur. Jet ve plaka arası mesafe (H/Dh) 12’de Re=9000 için ters yarım daire desenli yüzeylerin ortalama Nu sayısı, düz yamuk desenli yüzeylerden yaklaşık %56 daha fazladır.

Anahtar Kelimeler

• Jet giriş genişliği
• Çarpan hava jeti
• Desenli yüzey
• Isı transferi

Search of the Effect of Jet Inlet Width on Heat Transfer and Flow Character

Öz

In this study, the heat transfer was numerically researched by air jet flow from copper plate surfaces having different pattern shapes as flat trapezoid and reverse semi-circular in channels with different jet inlet widths. Numerical calculations were performed by solving the energy and Navier-Stokes equations in three dimensions and steady, using the Ansys-Fluent program with standard k-ε turbulence model. The top and bottom facets of the channels are adiabatic and fixed heat flux was implemented to the patterned facets. Jet entrance widths are Dh and 1,25Dh. The results of the study were compared with the numerical and experimental results of the work in the literature and it was obtained that they are compatible with one another. The results were exhibited as the average Nu number and variation of facet temperature for each patterned facet. The average Nu number of reverse semi-circular patterned facets is approximately 56% more than flat trapezoid patterned facets at distance between jet-plate (H/Dh) 12 for Re = 9000.

Anahtar Kelimeler

• Jet entrance width
• Impingement air jet
• Patterned facet
• Heat transfer

Kaynakça

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