60° EĞİMLİ İKİNCİL JETLERE SAHİP SINIRLANDIRILMIŞ ÇARPAN JET DİZİSİNDE ISI TRANSFERİ ETKİLERİNİN İNCELENMESİ

Yıl 2024, Sayı: 717, 598 - 627

Haluk Keleş , Yücel Özmen

Öz

Bu çalışmada, 60° eğimli ikincil jetlere sahip sınırlandırılmış çarpan dizi jet akışında çarpma yüzeyindeki ısı transferi etkileri hem deneysel hem de sayısal olarak incelenmiştir. Çalışmanın deneysel kısmında, Reynolds sayısı değerleri 20000 ve 30000, levhalar arası açıklık değerleri 0.5, 1, 3 ve 6 için çarpma levhasının merkez ekseni üzerince termal kamera ile sıcaklık dağılımları elde edilmiştir. Çalışmanın sayısal kısmında ise, Reynolds sayısının 30000 değerinde aynı açıklık değerleri için Standard k-ε ve Standard k-ω türbülans modellerinin Kato Launder ile modifiye edilmiş versiyonları kullanılarak 2-boyutlu çözümler gerçekleştirilmiş ve çarpma levhası üzerinde hesaplanan sıcaklık dağılımları deneysel sonuçlarla karşılaştırılmıştır. Ölçümlenen sıcaklık dağılımlarıyla, Reynolds sayısı ve levhalar arası açıklık değerlerinin çarpma levhası üzerindeki Nusselt dağılımlarına etkisi araştırılmıştır. Çarpma levhası boyunca Nusselt değerleri artan Reynolds sayısı ile artmakta, artan levhalar arası açıklık değerleri ile azalmaktadır. Çarpma levhası üzerinde ikincil jetlerin eksenleri doğrultusundaki çarpma konumlarında Nusselt sayısı pik değerler almakta ve oluşan piklerin konumları artan levhalar arası açıklı ile daha büyük ±r/D değerlerine kaymaktadır. Her iki türbülans modeliyle hesaplanan Nusselt dağılımlarının benzer olduğu ve çarpma bölgesinde hesaplanan sonuçların Standard k-ε ve Standard k-ω türbülans modelleri için sırasıyla % 9 ve % 11’lik hata payı ile deneysel sonuçlara uyum sağlandığı görülmektedir.

Anahtar Kelimeler

Çarpan dizi jet, eğimli ikincil jet, sınırlandırıcı levha, nusselt dağılımı, türbülans modeli

INVESTIGATION OF HEAT TRANSFER EFFECTS IN A CONFINED IMPINGING JET ARRAY WITH 60° INCLINED SECONDARY JETS

Öz

In this study, the effects of heat transfer on the impingement surface of a confined impinging array jet flow with 60° inclined secondary jets are investigated both experimentally and numerically. In the experimental section of the study, temperature distributions were obtained with a thermal camera among the middle axis of the impingement plate for 20000 and 30000 values of Reynolds number and 0.5, 1, 3 and 6 values of the aperture among plates. In the numerical section of the study, for the same Reynolds number and spacing values, bidimensional solutions were performed with the Kato Launder modified version of the Standard k-ε and Standard k-ω turbulence models and the calculated temperature distributions on the target impingement plate were compared with the experimental results. With measured temperature distributions, the effect of Reynolds number and aperture between plates on the Nusselt distributions on the target impingement plate is investigated. The Nusselt values on the surface of target impingement plate increase with increasing Reynolds number and decrease with increasing aperture between plates. The Nusselt number takes top point values at the impingement positions of the secondary jets on the impingement plate in the direction of their axes, and the positions of the top points shift to larger ±r/D values with increasing inter-plate spacing. It is observed that the Nusselt distributions calculated with both turbulence models are similar and the calculated results in the impingement region agree with the experimental results with a margin of error of 9 % and 11 % for the Standard k-ε and Standard k-ω turbulence models, respectively.

Anahtar Kelimeler

Impinging jet array, inclined secondary jet, confinement plate, nusselt distribution, turbulence model

Etik Beyan

Bu çalışmada araştırma ve yayın etiğine uyulmuştur.

Teşekkür

K.T.Ü. Makina Mühendisliği Bölümü’ne test ekipmanı ve programı sağladığı için teşekkür ederiz.

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