Application of Copper-Water Nanofluids to Improve the Heat Transfer Performance of Cooling System via free Convection Mechanism

Document Type : Research Article

Authors

1 School of Chemistry, College of Science, University of Tehran, Tehran, I.R. IRAN

2 School of Chemistry, Alborz Campus, University of Tehran, Tehran, I.R. IRAN

Abstract

In the present study, the natural convection heat transfer in a L-shape enclosure, filled with copper-water nanofluid is investigated by considering the effect of different factors such as aspect ratio, volume fraction of copper nanoparticles and Rayleigh number on the heat transfer coefficient, temperature and velocity distributions. All governing equations are solved by finite volume method. The results indicated that at high Rayleigh number, the dominant heat transfer mechanism will change from conduction to free convention and the maximum heat transfer coefficient will decrease. While at low Rayleigh numbers, the fluid in the horizontal part of the enclosure is approximately static and the predominant mechanism of heat transfer is conduction. The transition of conduction mechanism to free convection occurs at Rayleigh number in the range of 105 to 106. Also, the presence of copper nanoparticles, leads to significant enhancement in the heat transfer coefficient, for all values of Rayleigh number. In addition, the simulation results indicate that inclusion of a number of pins inside the enclosure has a significant effect on increasing the heat transfer coefficient. The achieved results indicated that inserting three fins in the structure of enclosure at aspect ratio of 0.4, nano particle volume fraction of 0.1 and Rayleigh number of 106 enhances the heat transfer coefficient from 984.3 to 1093.8 W/m2.K.

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[1] Naphon P., Wongwises S., Investigation on the Jet Liquid Impingement Heat Transfer for the Central Processing Unit of Personal Computers, International Communications in Heat and Mass Transfer, 37(7): 822-826 (2010).
[2] Palm S.J., Roy G., Nguyen C.T., Heat Transfer Enhancement with the Use of Nanofluids in Radial Flow Cooling Systems Considering Temperature-Dependent Properties, Applied Thermal Engineering, 26(17): 2209-2218 (2006).
[3] Xie Y.Q., Yu J.Z., Zhao Z.H., Experimental Investigation of Flow and Heat Transfer for the Ethanol-Water Solution and FC-72 in Rectangular Microchannels, Heat and Mass Transfer, 41(8): 695-702 (2005).
[4] Jiang P.X., Fan M.H., Si G.S., Ren Z.P., Thermal–Hydraulic Performance of Small Scale Micro-Channel and Porous-Media Heat-Exchangers, International Journal of Heat and Mass Transfer, 44(5): 1039-1051 (2001).
[5] کریمی ه.، سبزه میدانی، م.م.، مطالعه عددی تأثیر عامل‌های هندسی بر انتقال گرمای نانو سیال آب ـ Al2O3 در یک میکروکانال، نشریه شیمی و مهندسی شیمی ایران، (4)35: 137 تا 150 (1395).
[6] Rao Y., Liu Y., Wan C., Multiple-Jet Impingement Heat Transfer in Double-Wall Cooling Structures with Pin Fins and Effusion Holes, International Journal of Thermal Sciences, 133:106-119 (2018).
[7] Pachpute S., Premachandran B., Slot Air Jet Impingement Cooling Over a Heated Circular Cylinder with and without a Flow Confinement. Applied Thermal Engineering, 132: 352-367 (2018).
[8] Jiang P.X., Li M., Lu T.J., Yu L., Ren Z.P., Experimental Research on Convection Heat Transfer in Sintered Porous Plate Channels, International Journal of Heat and Mass Transfer, 47(10): 2085-2096 (2004).
[9] Hetsroni G., Gurevich M., Rozenblit R., Sintered Porous Medium Heat Sink for Cooling of High-Power Mini-Devices, International Journal of Heat and Fluid Flow, 27(2): 259-266 (2006).
[10] Bintoro J.S., Akbarzadeh A., Mochizuki, M., A Closed-Loop Electronics Cooling by Implementing Single Phase Impinging Jet and Mini Channels Heat Exchanger, Applied Thermal Engineering, 25(17): 2740-2753 (2005).
[11] Joshi Y., Kumar P., "Energy Efficient Thermal Management of Data Centers", Springer, 1st ed. London, New York, Dordrecht, Heidelberg (2012).
[12] Eastman J.A., Choi S.U.S., Li S., Yu W., Thompson L.J., Anomalously Increased Effective Thermal Conductivities of Ethylene Glycol-Based Nanofluids Containing Copper Nanoparticles, Appl Phys Lett, 78: 718-720 (2001).
[13] Xuan Y., Li Q., Heat Transfer Enhancement of Nanofluids, International Journal of Heat and Fluid Flow, 21(1): 58-64 (2000).
[14] Dinarvand S., Pop I., Free-Convective Flow of Copper/Water Nanofluid about a Rotating Down-Pointing Cone Using Tiwari-Das Nanofluid Scheme, Advanced Powder Technology, 28(3): 900-909 (2017).
[15] Kasaeipoor A., Ghasemi B., Aminossadati S.M., Convection of Cu-Water Nanofluid in a Vented T-Shaped Cavity in the Presence of Magnetic Field, International Journal of Thermal Sciences, 94: 50-60 (2015).
[17] Aminossadati S.M., Ghasemi B., Natural Convection Cooling of a Localised Heat Source at the Bottom of a Nanofluid-Filled Enclosure, European Journal of Mechanics - B/Fluids, 28(5): 630-640 (2009).
[18] Ghasemi B., Aminossadati S.M., Periodic Natural Convection in a Nanofluid-Filled Enclosure with Oscillating Heat Flux, International Journal of Thermal Sciences, 49(1): 1-9 (2010).
[19] Koca A., Oztop H.F., Varol Y., The Effects of Prandtl Number on Natural Convection in Triangular Enclosures with Localized Heating from Below, International Communications
in Heat and Mass Transfer
, 34(4): 511-519 (2007).
[20] Varol Y., Koca A., Oztop H.F., Natural Convection in a Triangle Enclosure with Flush Mounted Heater on the Wall, International Communications in Heat and Mass Transfer, 33(8): 951-958 (2006).
[21] Oztop H.F.,  Abu-Nada E., Numerical Study of Natural Convection in Partially Heated Rectangular Enclosures Filled with Nanofluids, International Journal of Heat and Fluid Flow, 29(5): 1326-1336 (2008).
[22] Mahmoodi M., Mixed Convection Inside Nanofluid Filled Rectangular Enclosures with Moving Bottom Wall, Thermal Science, 15(3): 889-903 (2011).
[23] Rudyak V.Y., Belkin A.A., Tomilina E.A., On the Thermal Conductivity of Nanofluids, Technical Physics Letters, 36(7): 660-662 (2010).
[24] Turgut A., Tavman I., Chirtoc M., Schuchmann H.P., Sauter C., Tavman S., Thermal Conductivity and Viscosity Measurements of Water-Based TiO2 Nanofluids, International Journal of Thermophysics, 30(4): 1213-1226 (2009).
[25] Ozisik M.N., "Heat Transfer a basic approach", McGraw-Hill, New York (1985).
[26] Maxwell J.C."A Treatise on Electricity and Magnetism", Oxford University Press, 2nd ed. UK, Cambridge (1904).
[27] Ishihara I., Fukui T.,  Matsumoto R., Natural Convection In A Vertical Rectangular Enclosure With Symmetrically Localized Heating and Cooling Zones, International Journal of Heat and Fluid Flow, 23(3): 366-372 (2002).
[28] Brinkman H.C., The Viscosity of Concentrated Suspensions and Solutions, The Journal of Chemical Physics, 20(4): 571-571(1952).
[29] Aly A.M., Raizah Z.A.S., Double-Diffusive Natural Convection in an Enclosure Filled with Nanofluid Using ISPH Method, Alexandria Engineering Journal, 55(4): 3037-3052 (2016).
[30] Mahmoodi M., Numerical Simulation of Free Convection of a Nanofluid in L-Shaped Cavities, International Journal of Thermal Sciences, 50(9): 1731-1740 (2011).
[31] Ferziger J.H., Perić M., "Computational Methods for Fluid Dynamics", Springer-Verlag, Berlin (1996).
[32] Tasnim S.H., Mahmud S., Laminar Free Convection Inside an Inclined L-Shaped Enclosure, International Communications in Heat and Mass Transfer, 33(8): 936-942 (2006).
[33] Aminossadati S.M., Ghasemi B., Natural Convection Cooling of a Localised Heat Source at the Bottom of a Nanofluid-Filled EnclosureEuropean Journal of Mechanics-B/Fluids28(5): 630-640 (2009).
[34] Chamkha A., Ismael M., Kasaeipoor A., Armaghani T., Entropy Generation and Natural Convection of CuO-Water Nanofluid in C-Shaped Cavity Under Magnetic Field, Entropy, 18(2): 50 (2016).