Sinan ÇALIŞKAN, Mustafa KILIÇ, Tamer ÇALIŞIR, Şenol BAŞKAYA

NUMERICAL INVESTIGATION OF HEAT TRANSFER USING IMPINGING JETS ON TRIANGULAR AND SQUARE RIBBED ROUGHENED WALLS

Bu çalışmada, çoklu çarpmalı jetler kullanarak üçgen ve kare kanatçıklı yüzeylerin soğutulması sunulmuştur. 7x3 olarak dikdörtgen dizilime sahip dairesel jetler kullanılarak çalışma gerçekleştirilmiştir. Re sayısının, jet-plaka mesafesinin ve kanatçık diziliminin akış ve ısı transferine olan etkisi sayısal olarak irdelenmiştir. İki kanatçık dizilimi incelenmiştir. A dizilimi jetlerin doğrudan kanatçıkların üstüne çarpmasını, B dizilimi ise jetlerin iki kanatçığın ortasına çarpması durumlarını göstermektedir. İki komşu jetin duvar jetleri artan Re sayısı ile daha şiddetli bir şekilde etkileşmektedir. En yüksek ve en düşük ortalama ısı transferi değerleri tüm kanatçık geometrilerinde sırasıyla H/d=8 ve H/d=4-6 oluşmaktadır. Üçgen kanatçıklı yüzeylerde çarpma noktası Nu sayısı değerleri A düzenlemesinde B düzenlemesine göre daha yüksek olduğu görülmüştür

ÜÇGEN VE KARE KANATÇIKLI YÜZEYLER ÜSTÜNDEKİ ÇARPAN AKIŞKAN JETLER KULLANILARAK ISI TRANSFERİNİN SAYISAL İNCELENMESİ

This paper presents a heat removal study on triangular and square ribbed surfaces under an array of impinging air jets. The investigation was carried out using nozzles with a 7x3 rectangular array of circular jets. The effect of Re number, jet-to-plate distance, and rib arrangement on heat transfer and fluid flow characteristics was examined numerically. Two arrangements have been studied. Arrangement A considers the situation when the cooling jets are directed towards the ribs, while arrangement B considers the situation when the jets are directed towards the centre line of the cavity between two ribs. Wall jets of neighboring jets have a stronger interaction with increasing Reynolds number. The lowest and highest local heat transfer for all rib geometries was obtained for H/d=8 and H/d=4-6, respectively. On triangular ribbed surfaces the stagnation point Nusselt number values for arrangement A are significantly higher than the stagnation point Nusselt numbers for arrangement B

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