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The First and Second Law Analyses of Thermodynamics for CoFe2O4/H2O Flow in a Sudden Expansion Tube Inserted Elliptical Dimpled Fins     
Yazarlar
Hayati Kadir Pazarlıoğlu
Emrehan Gürsoy
Doç. Dr. Mehmet GÜRDAL
Kastamonu Üniversitesi, Türkiye
Mutlu Tekir
Karabük Üniversitesi, Türkiye
Engin Gedik
Türkiye
Kamil Arslan
Karabük Üniversitesi, Türkiye
Edip Taşkesen
Şırnak Üniversitesi, Türkiye
Özet
In this paper, thermo-hydraulic performance and entropy generation of the sudden expansion tube with elliptical dimpled fins (DFs) at different directions was computationally performed at different Reynolds (Re) numbers ranging between 100≤Re≤2000 using cobalt ferrite/H2O (CoFe2O4/H2O) nanofluid (NF) (0.0≤φ≤ 2.0). The novelty of this study is to investigate the effect of the elliptical DF and its arrays in the sudden expansion tube in terms of thermodynamics laws (energy and entropy generations). While the sudden expansion ratio (D2/D1) is 2.5, elliptical dimple width (a) and height (b) show variations between 4 and 8 mm. In addition, the distances among elliptical DFs (P) are taken as P = 10, 15, and 20 mm while the diameter (D1) and length (L1) of the inlet tube are D1=8 mm and L1=375 mm. The diameter (D2) and length (L2) of the tube with the sudden expanding and elliptical DFs are D2=20 mm and L2=1125 mm, respectively. The study comprehensively exhibits results of the thermo-hydraulic performance and entropy generation based on numerical data. The results demonstrated that the highest heat transfer rate is recorded by the case of DT3, and DT3 enhances the convective heat transfer rate by 221%, and increases the pressure drop by 17.38% at Re=2000 compared to smooth tube (ST). It was observed that as the Re increases, the performance evaluation criteria (PEC) gradually increases too, and the highest PEC has been obtained for DT3 as 2.11 at Re=2000. The entropy generation (EnG) was also evaluated in terms of both geometric designs and volumetric concentrations. Moreover, the best total EnG was found around 17% for DT3 at the Re=1000 and φ=2.0% compared to ST using H2O. Consequence of the applied analyses, the use of elliptic DFs in a sudden expansion tube enhances the convective heat transfer rate and decreases total EnG.
Anahtar Kelimeler
Entropy generation,Convective heat transfer,CFD,Elliptical dimpled fin,Sudden expansion tube
Makale Türü Özgün Makale
Makale Alt Türü SSCI, AHCI, SCI, SCI-Exp dergilerinde yayımlanan tam makale
Dergi Adı International Journal of Mechanical Sciences
Dergi ISSN 0020-7403
Dergi Tarandığı Indeksler SCI
Dergi Grubu Q1
Makale Dili Türkçe
Basım Tarihi 05-2023
Cilt No 246
Doi Numarası 10.1016/j.ijmecsci.2023.108144
Makale Linki https://www.sciencedirect.com/science/article/pii/S0020740323000462