# THREE-DIMENSIONAL CFD MODELING OF TiO2/R134a NANOREFRIGERANT

## Main Article Content

## Abstract

In this study, numerical investigations were carried out for R134a based TiO_{2} nanorefrigerants. Forced laminar flow and heat transfer of nanorefrigerants in a horizontal smooth circular cross-sectioned duct were investigated under steady-state condition. The nanorefrigerants consist of TiO2 nanoparticles suspended in R134a as a base fluid with four particle volume fractions of 0.8, 2.0 and 4.0%. Numerical studies were performed under laminar flow conditions where Reynolds numbers range from 8×102 to 2.2×10^{3}. Flow is flowing in the duct with hydrodynamically and thermally developing (simultaneously developing flow) condition. The uniform surface heat flux with uniform peripheral wall heat flux (H2) boundary condition was applied on the duct wall. Commercial CFD software, Ansys Fluent 14.5, was used to carry out the numerical study. Effect of nanoparticle volume fraction on the average convective heat transfer coefficient and average Darcy friction factor were analyzed. It is obtained in this study that increasing nanoparticle volume fraction of nanorefrigerant increases the convective heat transfer in the duct; however, increasing nanoparticle volume fraction does not influence the pressure drop in the duct. The velocity and temperature distribution in the duct for different Reynolds numbers and nanoparticle volume fractions were presented.

## Article Details

**Thermal Science**, [S.l.], mar. 2017. ISSN 2334-7163. Available at: <http://thermal-science.tech/journal/index.php/thsci/article/view/2072>. Date accessed: 24 nov. 2017. doi: https://doi.org/10.2298/TSCI140425002A.

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Accepted 2017-03-13

Published 2017-03-13

## References

[2] Moraveji, M. K., Ardehali, R. M., CFD Modeling (Comparing Single and Two-Phase Approaches) on Thermal Performance of Al2O3/Water Nanofluid in Mini-Channel Heat Sink, International Communications in Heat and Mass Transfer, 44 (2013), pp. 157-164.

[3] Moraveji, M. K., Darabi, M., Haddad, S. M. H., Davarnejad, R., Modeling of Convective Heat Transfer of a Nanofluid in the Developing Region of Tube Flow with Computational Fluid Dynamics, International Communications in Heat and Mass Transfer, 38 (2013), pp. 1291- 1295.

[4] Moraveji, M. K., Ardehali, R. M., Ijam, A., CFD Investigation of Nanofluid Effects (Cooling Performance and Pressure Drop) in Mini-Channel Heat Sink, International Communications in Heat and Mass Transfer, 40 (2013), pp. 58-66.

[5] Moraveji, M. K., Haddad, S. M. H., Darabi, M., Modeling of Forced Convective Heat Transfer of a Non-Newtonian Nanofluid in the Horizontal Tube Under Constant Heat Flux with Computational Fluid Dynamics, International Communications in Heat and Mass Transfer, 39 (2012), pp. 995-999.

[6] Hussein, A. M., Sharma, K.V., Bakar, R. A., Kadirgama, K., The Effect of Cross-Sectional Area of Tube on Friction Factor and Heat Transfer Nanofluid Turbulent Flow, International Communications in Heat and Mass Transfer, 47 (2013), pp. 49-55.

[7] Hussein, A. M., Bakar, R. A., Kadirgama, K., Sharma, K.V., Heat Transfer Enhancement with Eliptical Tube Under Turbulent Flow TiO2-Water Nanofluid, Thermal Science, doi: 10.2298/TSCI130204003H.

[8] Moraveji, M. K., Hejazian, M., Modeling of Turbulent Forced Convective Heat Transfer and Friction Factor in a Tube for Fe3O4 Magnetic Nanofluid with Computational Fluid Dynamics, International Communications in Heat and Mass Transfer, 39 (2012), pp. 1293-1296.

[9] Lelea, D., Nisulescu, C., The Micro-Tube Heat Transfer and Fluid Flow of Water Based Al2O3 Nanofluid with Viscous Dissipation, International Communications in Heat and Mass Transfer, 38 (2011), pp. 704-710.

[10] Hojtat, M., Etemad, S. G., Bagheri, R., Thibault, J., Laminar Convective Heat Transfer of Non- Newtonian Nanofluids with Constant Wall Temperature, Heat and Mass Transfer, 47 (2011), 2, pp. 203-209.

[11] Mohammed, H.A., Gunnasegaran, P., Shuaib, N.H., Heat Transfer in Rectangular Microchannels Heat Sink Using Nanofluids, International Communications in Heat and Mass Transfer, 37 (2010), pp. 1496-1503.

[12] Bianco, V., Chiacchio, F., Manca, O., Nardini, S., Numerical Investigation of Nanofluids Forced Convection in Circular Tubes, Applied Thermal Engineering, 29 (2009), 17-18, pp. 3632-3642.

[13] Chein, R., Chuang, J., Experimental Microchannel Heat Sink Performance Studies Using Nanofluids, International Journal of Thermal Sciences, 46 (2007), 1, pp. 57-66.

[14] Heris S. Z., Etemad, S. G., Esfahany, M. N., Convective Heat Transfer of a Cu/Water Nanofluid Flowing Through a Circular Tube, Experimental Heat Transfer, 22 (2009), 4, pp. 217-227.

[15] Li, Q., Xuan, Y., Convective Heat Transfer and Flow Characteristics of Cu-Water Nanofluid, Science in China (Series E), 45 (2002), 4, pp. 408-416.

[16] Yang, Y., Zhang, Z. G., Grulke, E. A., Anderson, W. B., Wu, G., Heat Transfer Properties of Nanoparticle-in-Fluid Dispersions (Nanofluids) in Laminar Flow, International Journal of Heat and Mass Transfer, 48 (2005), 6, pp. 1107-1116.

[17] Kaya, O., Numerical Study of Turbulent Flow and Heat Transfer of Al2O3-Water Mixture in a Square Duct with Uniform Heat Flux, Heat and Mass Transfer, 49 (2013), 11, pp. 1549-1563.

[18] Salman, B. H., Mohammed, H. A., Munisamy, K. M., Kherbeet, A. Sh., Characteristics of Heat Transfer and Fluid Flow in Microtube and Microchannel Using Conventional Fluids and Nanofluids: A Review, Renewable and Sustainable Energy Reviews, 28 (2013), pp. 848-880.

[19] Kuppusamya, N. R., Mohammed, H. A., Lim, C. W., Numerical Investigation of Trapezoidal Grooved Microchannel Heat Sink Using Nanofluids, Thermochimica Acta, 573 (2013) pp. 39- 56.

[20] Kherbeet, A. Sh., Mohammed, H. A., Munisamy, K. M., Salman, B. H., The Effect of Step Height of Microscale Backward-Facing Step on Mixed Convection Nanofluid Flow and Heat Transfer Characteristics, International Journal of Heat and Mass Transfer, 68 (2014), pp. 554- 566.

[21] Mohammed, H. A., Narrein, K., Thermal and Hydraulic Characteristics of Nanofluid Flow in a Helically Coiled Tube Heat Exchanger, International Communications in Heat and Mass Transfer, 39 (2012), pp. 1375-1383.

[22] Tokit, E. M., Mohammed, H. A., Yusoff, M. Z., Thermal Performance of Optimized Interrupted Microchannel Heat Sink (IMCHS) Using Nanofluids, International Communications in Heat and Mass Transfer, 39 (2012), pp. 1595-1604.

[23] Bi, S., Guo, K., Liu, Z., Wu, J., Performance of a Domestic Refrigerator Using TiO2-R600a Nano-Refrigerant as Working Fluid, Energy Conversion and Management, 52 (2011), 1, pp. 733-737.

[24] Saidur, R., Kazi, S. N., Hossain, M. S., Rahman, M. M., Mohammed, H. A., A Review on the Performance of Nanoparticles Suspended with Refrigerants and Lubricating Oils in Refrigeration Systems, Renewable and Sustainable Energy Reviews, 15 (2011), 1, pp. 310-323.

[25] Jiang, W. T., Ding, G. L., Peng, H., Measurement and Model on Thermal Conductivities of Carbon Nanotube Nanorefrigerants, International Journal of Thermal Science, 48 (2009), 6, pp. 1108-1115.

[26] Peng, H., Ding, G., Jiang, W., Hu, H., Gao, Y., Heat Transfer Characteristics of Refrigerant- Based Nanofluid Flow Boiling inside a Horizontal Smooth Tube, International Journal of Refrigeration, 32 (2009), 6, pp. 1259–1270.

[27] Jwo, C. S., Jeng, L. Y., Teng, T. P., Chang, H., Effects of Nanolubricant on Performance of Hydrocarbon Refrigerant System, Journal of Vacuum Science and Technology B, 27 (2009), pp. 1473-1477.

[28] Vajjha, R. S., Das, D. K., Experimental Determination of Thermal Conductivity of Three Nanofluids and Development of New Correlations, International Journal of Heat and Mass Transfer, 52 (2009), pp. 4675-4682.

[29] Incropera, F. P., Dewitt, D. P., Bergman, T. L., Lavine, A. S., Foundations of Heat Transfer, 6th Ed., John Wiley & Sons Inc., Singapore, 2013, pp. 897-924.

[30] Çengel, Y. A., Ghajar, A. J., Heat and Mass Transfer Fundamentals and Applications, 4th Ed., McGraw-Hill, USA, 2011, pp. 473.

[31] Patankar, S. V., Numerical Heat Transfer and Fluid Flow, Hemisphere Publishing Corporation, USA, 1980, pp. 126-131.

[32] Arslan, K., Three Dimensional Numerical Investigation of Turbulent Flow and Heat Transfer inside a Horizontal Semi-Circular Cross-Sectioned Duct, Thermal Science, doi:10.2298/TSCI110724065A.

[33] Sieder, E. N., Tate, G. E., Heat Transfer and Pressure Drop of Liquid in Tubes, Industrial Engineering Chemistry, 28 (1936), 12, pp. 1429-1435.