Gürşah GÜRÜF, İsmail SOLMUŞ, Cihan YILDIRIM, Kadir BİLEN

Modifiye Grafit Köpük İle Hava Arasındaki Ortalama Hacimsel Isı Taşınım Katsayısının Tayini

Bu çalışmada, zamana bağlı tek akım yöntemi vasıtasıyla akış yönünde 2 mm çapında kanalların açıldığı modifiye grafit köpük malzeme ile hava arasındaki ortalamahacimsel ısı taşınım katsayısı, Reynolds sayısının (Re) ve malzeme uzunluğu/genişliği oranının (L/W) fonksiyonu olarak formunda ampirik bir korelasyon denklemiile ifade edilmiştir. Modifiye grafit malzemenin yüksekliği (H), genişliği (W) ve gözeneklilik değeri (ε) sırasıyla 27 mm, 52 mm ve 0.113 olup akışın tamamen kanallariçerisinden gerçekleştiği varsayılmıştır. Zamana bağlı tek akım yöntemi hem deneysel hem de teorik çalışma içermektedir. Deneysel çalışma geniş bir Reynolds sayısıaralığında (1000-10000) ve 3 farklı malzeme uzunluğu/genişliği değerinde (0,52, 1,1,46) yapılmış olup teorik çalışma ise deneylerin ardından elde edilen veriler çerçevesinde MatLab ortamında geliştirilen bilgisayar simülasyon programı vasıtasıylayürütülmüştür.

Determination of Average Volmetric Heat Transfer Coefficient Between Modified Graphite Foam and the Air

In this study, the relation which gives the volumetric heat transfer coefficient between the modified graphite foam material and the air is expressed as a function of Re number Material length / width (L/W) ratio with the empirical correlation equation in the form of using transient single blow technique. The graphite foam is modified by machining 2 mm cylindrical air passages in the axial direction. The height (H), width (W) and porosity (ε) of the modified graphite material are 27 mm, 52 mm and 0,113 respectively and it is assumed that the flow is entirely carried out through the air passages. Transient single blow technique includes both experimental and theoretical work. The experimental study is carried out for a wide range of Re number (1000-10000) and 3 different material length / width value and then, theoretical study based on the data obtained in the experiments is conducted by means of a computer simulation program developed in the MatLab environment.

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