Boyuna Uzatılmış Yüzeylerde Dikdörtgensel Oyukların Isı Atımına Etkisi:Bir Hesaplamalı Akışkanlar Dinamiği Analizi

Bu çalışmada, üç farklı zorlanmış taşınım koşulu için (h = 25, 50 ve 100 W/$m^2$K) konvansiyonel ve oyuklukanatlardan olan ısı transferi ANSYS FLUENT yazılımı ile incelendi ve analizler çeşitli oyuk seviyeleri için tekrarlandı. Analizlerde kanat malzemesi olarak 202.4 W/mK ısıl iletkenliğe sahip alüminyum kullanıldı. Operasyonel durum için fotovoltaik sistemlerin zorlanmış taşınımla soğutulması durumu göz önüne alındı ve bu bağlamda, kanat taban sıcaklığı, standart test koşullarını (1000 W/$m^2$ışınım akısı, 298.15 K çevre sıcaklığı) göz önünde bulundurarak 353.15 K seçildi. Sürekli rejim koşullarında kanat boyunca enerji denklemi ? = $10^{−9}$yakınsama kriteri ile çözüldü. Çalışmada dikkate alınan referans kanat profili 50 mm boy, 10 mm yükseklik ve 1 mm kalınlık ölçülerine sahiptir. Kanat boyunca boylamasına 1 mm2’lik oyuk çiftleri (λ) oluşturuldu ve her bir λ değeri için konvansiyonel ve oyuklu kanatlardan olan ısı atımları sayısal olarak belirlendi. Kanat verimi oyuk seviyesinin bir fonksiyonu olarak ayrıca hesaplandı. Sayısal sonuçlar, artan λ değeri ile kanattan olan ısı atımının azaldığını, ancak bütün taşınım koşulları için, belirli bir λ değerinden sonra birim kanat hacminden olan ısı atımının konvansiyonel kanata kıyasla daha fazla olduğunu gösterdi. Düşük h değerlerinde oyuk etkilerinin daha belirgin olduğu görüldü. h = 25 W/$m^2$K için konvansiyonel kanattan olan ısı atımı 2.5032 W iken, λ = 24 için oyuklu kanattan olan ısı atımı 2.6683 W olarak belirlendi. Bu durum ısı atımında yaklaşık %6.6’lık bir iyileşmeye karşılık gelmektedir

Impacts of Rectangular Perforations in Longitudinal Extended Surfaces on Heat Dissipation: A Computational Fluid Dynamics Analysis

In this study, for three different forced convection conditions (h = 25, 50 and 100 W/$m^2$K), heat transferthrough conventional and perforated fins has been investigated by ANSYS FLUENT software, and theanalyses have been repeated for various perforation levels. Aluminium has been utilised as the finmaterial in the analyses with a thermal conductivity of 202.4 W/mK. For the operational case, coolingof photovoltaic systems by forced convection has been considered, and in this respect, fin basetemperature has been selected to be 353.15 K by taking standard test conditions (1000 W/$m^2$ solarintensity, 298.15 K ambient temperature) into consideration. For steady-state conditions, energyequation has been solved along the fin for the convergence criterion of ? = $10^{−9}$ . Reference fin profileconsidered in the research has a 50 mm length, 10 mm height and 1 mm width. Perforation pairs (λ) of1 mm2 have been formed longitudinally along the fin and the heat dissipations from conventional andperforated fins have been numerically determined for each λ value. Fin efficiency has also beencalculated as a function of perforation level. Numerical results have revealed that heat transfer fromthe fin decreases with increasing λ value, however for each convection condition, heat dissipation perfin volume from the perforated fin is greater in comparison to the conventional fin after a certain λvalue. Perforation effects have been found more noticeable for the lower h values. For h = 25 W/$m^2$K,heat dissipation from the conventional fin has been determined to be 2.5032 W whereas the heattransfer through the perforated fin has been found to be 2.6683 W. This case corresponds to anenhancement of about 6.6% in heat dissipation.

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