Thermal Performance of a Tube Equipped with V-nozzle Turbulator Inserts

Year 2018, , 42 - 54, 30.03.2018

Sibel Güneş , Orhan Keklikcioğlu , Toygun Dağdevir , Veysel Özceyhan

https://doi.org/10.31200/makuubd.349798

Abstract

This study pertains to the numerical investigation of the influence of V-nozzle turbulators on thermal performance in a circular tube under uniform heat flux condition. The converging-diverging nozzles as a venturi structure were located in the test tube in order to generate turbulance/reverseflow. The computations were carried out by consideration of various pitch ratios, PR = 2, 4, and 6 for Reynolds numbers between 5000 and 32000, using air as a working fluid. The variation of Nusselt number (Nu) and friction factor (f) versus Reynolds number (Re) were introduced for the obtained numerical results. The plain tube results were compared with the works available in literature for confirmation of the used numerical method. Consequently, the results demonstrated that the usage of V-nozzles at smaller pitch ratio yielded an increase in heat transfer rate and pressure loss.

Keywords

V-nozzle, Turbulent flow, Thermal performance

V-Lüle Türbülator Yerleştirilen Bir Borunun Termal Performansı

Abstract

Bu çalışma da sabit ısı akısı uygulanan silindirik bir boru içerisindeki V-lüle türbülatörlerin ısıl performansa etkisi sayısal olarak incelenmiştir. Ventüri yapısına benzer ıraksak ve yakınsak lüleler test borusu içerisine türbülans/tersakış oluşturmak amacıyla yerleştirilmiştir. Hesaplamalar PR=2,4 ve 6 Reynolds sayısının ise 5000 ile 32000 aralığında değiştiği farklı değerlerde hava akışkanı kullanılarak gerçekleştirilmiştir. Elde edilen sayısal sonuçlar için Nusselt sayısı (Nu) ve sürtünme faktörü (f) ile Reynolds sayısı (Re) arasındaki değişim ortaya konulmuştur. Boş boru sonuçları, kullanılan sayısal yöntemin doğrulanması için literatürde bulunan diğer çalışmalar karşılaştırılmıştır. Sonuç olarak, elde edilen sonuçlar daha küçük hatve oranında V-lüle kullanımının ısı transferi miktarında ve basınç kaybında bir artış sağladığını göstermiştir.

Keywords

V-lüle, Türbülanslı akış, Isıl performans

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