Noora İmad Haseeb ALGBURI, Hayati Kadir PAZARLIOĞLU, Kamil ARSLAN

Türbülanslı Akış Durumunda Isı Kuyusunun İğne Kanatçığının Adım Oranının ve Köşegen Uzunluğunun Konvektif Isı Transferine Etkisi

Bu çalışmada, türbülanslı akış rejimi altında ısı kuyusunun termo-hidrolik performansını belirlemek için ısı kuyusu üzerindeki iğne kanatçığın köşegen uzunluğu ve adım oranının etkisi sayısal olarak araştırılmıştır. Genel kanatçık tiplerine kıyasla daha az basınç düşümüne sebep olduğu için iğne kanatçık kullanımı tercih edilmiştir. Geometrik paramtere olarak, adım oranı 0.75 ≤ P/e ≤ 1.1 değiştirilirken, iğne kanatçığın köşe uzunluğu 3 ≤ Lef ≤ 6 olarak değiştirilmiştir. Çalışma aralığı türbulanslı akış rejimi olarak düşünülmüştür (2658 ≤ Re ≤ 7138). Hesaplamalı çalışmada RANS denklemlerini çözmek için low-Re düzeltme modeli ile SST k-ω kullanılarak ANSYS Fluent 2020R2 üzerinde gerçekleştirilmiştir. Termo-hidrolik performansı ifade eden ortalama Nusselt sayısı, Ortalama Darcy sürtünme faktörü ve termal rezistans gibi faktörler detaylıca ele alınmıştır. Ayrıca, akış karakteristiğini detaylıca inceleyebilmek için girdap ve sıcaklık eş eğrileri ve hız akış çizgileri oluşturulmuştur. Genel değerlendirme sonucu olarak, Re=7138’de maksimum konvektif ısı transferi performansı Case 1’e kıyasla %52 oranla Case 12 kullanılarak elde edilmiştir.

Anahtar Kelimeler:

Isı kuyusu, Altıgen iğne kanatçık, Konvektif ısı transferi, HAD

Effect of Pitch Ratio and Diagonal Length of Pin Fin of Heat Sink on Convective Heat Transfer for Turbulent Flow Condition

In this study, the impact of pitch ratio and diagonal length of pin fin on the heat sink has been numerically investigated to determine the thermo-hydraulic performance of heat sink under turbulent flow regime. Usage of pin fin on the heat sink has been preferred due to less pressure drop in comparison with general fin type. While the pitch ratio has been changed 0.75 ≤ P/e ≤ 1.1, the length of edge of fin has been changed 3 ≤ Lef ≤ 6 as geometric parameters. The working range of the study has been considered as turbulent flow regime (2658 ≤ Re ≤ 7138). The computational study has been carried out on ANSYS Fluent 2020R2 using SST k-ω with low-Re correction model to calculate RANS equations. The factors, which define thermo-hydraulic performance of the study, such as average Nusselt number, average Darcy friction factor, and thermal resistance has been elucidated in detail. Also, to detect flow characteristics comprehensively, the contours have been created for vorticity, temperature, and velocity streamline. As a results of overall assessment of this study, it is concluded that the maximum convective heat transfer performance has been obtained using Case 12 by 52% compared with the Case 1 at Re=7138.

Keywords:

Heat sink, Hexagonal pin fin, Convective heat transfer, CFD.,

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E.M.S. El-Said, G.B. Abdelaziz, S.W. Sharshir, A.H. Elsheikh, A.M. Elsaid, Experimental investigation of the twist angle effects on thermo-hydraulic performance of a square and hexagonal pin fin array in forced convection, Int. Commun. Heat Mass Transf. 126 (2021) 105374. https://doi.org/10.1016/J.ICHEATMASSTRANSFER.2021.105374.
B. Sahin, K. Yakut, I. Kotcioglu, C. Celik, Optimum design parameters of a heat exchanger, Appl. Energy. 82 (2005) 90–106. https://doi.org/10.1016/J.APENERGY.2004.10.002.
Y.F. Pang, Assessment of Thermal Behavior and Development of Thermal Design Guidelines for Integrated Power Electronics Modules, (2005).
N.A.C. Sidik, M.N.A.W. Muhamad, W.M.A.A. Japar, Z.A. Rasid, An overview of passive techniques for heat transfer augmentation in microchannel heat sink, Int. Commun. Heat Mass Transf. 88 (2017) 74–83. https://doi.org/10.1016/J.ICHEATMASSTRANSFER.2017.08.009.
M. Turkyilmazoglu, Effective computation of solutions for nonlinear heat transfer problems in Fins, J. Heat Transfer. 136 (2014) 1–6. https://doi.org/10.1115/1.4027772.
M. Turkyilmazoglu, Efficiency of heat and mass transfer in fully wet porous fins: Exponential fins versus straight fins, Int. J. Refrig. 46 (2014) 158–164. https://doi.org/10.1016/J.IJREFRIG.2014.04.011.
L. Lin, J. Zhao, G. Lu, X.D. Wang, W.M. Yan, Heat transfer enhancement in microchannel heat sink by wavy channel with changing wavelength/amplitude, Int. J. Therm. Sci. 118 (2017) 423–434. https://doi.org/10.1016/J.IJTHERMALSCI.2017.05.013.
N. Patel, H.B. Mehta, Experimental investigations on a variable channel width double layered minichannel heat sink, Int. J. Heat Mass Transf. 165 (2021) 120633. https://doi.org/10.1016/J.IJHEATMASSTRANSFER.2020.120633.
H. Mousavi, A.A. Rabienataj Darzi, M. Farhadi, M. Omidi, A novel heat sink design with interrupted, staggered and capped fins, Int. J. Therm. Sci. 127 (2018) 312–320. https://doi.org/10.1016/J.IJTHERMALSCI.2018.02.003.
Y. Yan, Z. He, G. Wu, L. Zhang, Z. Yang, L. Li, Influence of hydrogels embedding positions on automatic adaptive cooling of hot spot in fractal microchannel heat sink, Int. J. Therm. Sci. 155 (2020) 106428. https://doi.org/10.1016/J.IJTHERMALSCI.2020.106428.
M. Izadi, Effects of porous material on transient natural convection heat transfer of nano-fluids inside a triangular chamber, Chinese J. Chem. Eng. 28 (2020) 1203–1213. https://doi.org/10.1016/J.CJCHE.2020.01.021.
M. Izadi, M.A. Sheremet, S.A.M. Mehryan, I. Pop, H.F. Öztop, N. Abu-Hamdeh, MHD thermogravitational convection and thermal radiation of a micropolar nanoliquid in a porous chamber, Int. Commun. Heat Mass Transf. 110 (2020) 104409. https://doi.org/10.1016/J.ICHEATMASSTRANSFER.2019.104409.
M. Izadi, M. Javanahram, S.M.H. Zadeh, D. Jing, Hydrodynamic and heat transfer properties of magnetic fluid in porous medium considering nanoparticle shapes and magnetic field-dependent viscosity, Chinese J. Chem. Eng. 28 (2020) 329–339. https://doi.org/10.1016/J.CJCHE.2019.04.024.
Y. Yoon, S.J. Park, D.R. Kim, K.S. Lee, Thermal performance improvement based on the partial heating position of a heat sink, Int. J. Heat Mass Transf. 124 (2018) 752–760. https://doi.org/10.1016/J.IJHEATMASSTRANSFER.2018.03.080.
H.M. Ali, A. Arshad, M. Jabbal, P.G. Verdin, Thermal management of electronics devices with PCMs filled pin-fin heat sinks: A comparison, Int. J. Heat Mass Transf. 117 (2018) 1199–1204. https://doi.org/10.1016/J.IJHEATMASSTRANSFER.2017.10.065.
P.A. Deshmukh, R.M. Warkhedkar, Thermal performance of elliptical pin fin heat sink under combined natural and forced convection, Exp. Therm. Fluid Sci. 50 (2013) 61–68. https://doi.org/10.1016/J.EXPTHERMFLUSCI.2013.05.005.
P. Bhandari, Y.K. Prajapati, Thermal performance of open microchannel heat sink with variable pin fin height, Int. J. Therm. Sci. 159 (2021) 106609. https://doi.org/10.1016/J.IJTHERMALSCI.2020.106609.
K.S. Ong, C.F. Tan, K.C. Lai, K.H. Tan, Heat spreading and heat transfer coefficient with fin heat sink, Appl. Therm. Eng. 112 (2017) 1638–1647. https://doi.org/10.1016/J.APPLTHERMALENG.2016.09.161.
M. Ozsipahi, A. Subasi, H. Gunes, B. Sahin, Numerical investigation of hydraulic and thermal performance of a honeycomb heat sink, Int. J. Therm. Sci. 134 (2018) 500–506. https://doi.org/10.1016/J.IJTHERMALSCI.2018.07.034.
Z. Soleymani, M. Rahimi, M. Gorzin, Y. Pahamli, Performance analysis of hotspot using geometrical and operational parameters of a microchannel pin-fin hybrid heat sink, Int. J. Heat Mass Transf. 159 (2020) 120141. https://doi.org/10.1016/J.IJHEATMASSTRANSFER.2020.120141.
S.-L. Wang, L.-Y. Chen, B.-X. Zhang, Y.-R. Yang, X.-D. Wang, A new design of double-layered microchannel heat sinks with wavy microchannels and porous-ribs, J. Therm. Anal. Calorim. 141 (2020) 547–558. https://doi.org/10.1007/s10973-020-09317-3.
T. Saravanakumar, S.D. Kumar, Heat transfer study on different surface textured pin fin heat sink, Int. Commun. HEAT MASS Transf. 119 (2020).
M.R. Attar, M. Mohammadi, A. Taheri, S. Hosseinpour, M. Passandideh-Fard, M. Haddad Sabzevar, A. Davoodi, Heat transfer enhancement of conventional aluminum heat sinks with an innovative, cost-effective, and simple chemical roughening method, Therm. Sci. Eng. Prog. 20 (2020) 100742. https://doi.org/10.1016/J.TSEP.2020.100742.
H.K. Pazarlıoğlu, R. Ekiciler, K. Arslan, Numerical Analysis of Effect of Impinging Jet on Cooling of Solar Air Heater with Longitudinal Fins, Heat Transf. Res. 52 (2021). https://doi.org/10.1615/heattransres.2021037251.