Mustafa KILIÇ, Tamer ÇALIŞIR, Sinan ÇALIŞKAN, Şenol BAŞKAYA

Çarpan akışkan jetleri kullanarak kanatçıklı yüzeyler üzerindeki akış alanının sayısal olarak incelenmesi

Bu çalışmada, 7x3 olarak dikdörtgen dizilime sahip dairesel jetler kullanılarak üçgen ve kare kanatçıkbulunan yüzeyler üzerine çarptırılması sonucu oluşan akış yapısı sayısal olarak incelenmiştir. Re sayısının,jet-plaka mesafesinin (H/d) ve kanatçık geometrisinin akışa etkisi irdelenmiştir. Çalışmada önceliklematematiksel formülasyon ve sınır şartları sunulmuş ve sonrasında oluşturulan sayısal model literatürdebulunan deneysel verilerle doğrulanmıştır. Gerçekleştirilen çalışmada hız konturları gösterilmiş vesonrasında jetlerdeki eksenel ve radyal hız dağılımları sunulmuştur. Ayrıca türbülans etkilerinin görülmesiamacıyla türbülans kinetik enerjisi dağılımları sunulmuştur. Kare kanatçıklı yüzey üstünde jet akışı kanatçık üstünde ayrışmaktadır. Hızın artması ile birlikte kare kanatçıklar üstündeki ayrışma da daha erken gerçekleşmektedir. H/d=2 olduğu durumda duvar jetleri daha etkilidir ve iki komşu jetin duvar jetietkileşmektedir. Bu nedenle üçgen kanatçıklı yüzeyler üstündeki duvar jetlerinin hızı daha yüksek olmaktadır.

Numerical investigation of flow field on ribbed surfaces using impinging jets

This paper presents the numerical investigation of the flow field of triangular and square ribbed surfacesunder a 7x3 rectangular array of circular impinging air jets. The effect of Re number, jet-to-plate distance (H/d) and rib geometry on fluid flow characteristics was examined. Firstly, the mathematical formulationand boundary conditions were presented and afterwards the numerical model was verified withexperimental results from the literature. Velocity contours were shown and axial and radial velocitydistributions were presented. Additionally, the turbulence kinetic energy distribution was shown. Aseparation of the jet flow occurs for square ribbed surfaces before impingement. For square ribbed surfaces the separation of the jet occurs at a higher location with increasing inlet velocity. Wall jets interact moreeffectively for the case of H/d=2. The velocity values of the wall jets for the case of triangular ribbedsurface is therefore higher.

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