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Heat transfer and friction characteristics were numerically investigated, employing elliptical tube to increase the heat transfer rate with a minimum increase of pressure drop. The flow rate of the tube was in a range of Reynolds number between 10000 and 100000. FLUENT software is used to solve the governing equation of CFD (continuity, momentum and energy) by means of a finite volume method (FVM). The electrical heater is connected around the elliptical tube to apply uniform heat flux (3000 W/m2) as a boundary condition. Four different volume concentrations in the range of 0.25% to 1% and different TiO2 nanoparticle diameters in the range of 27 nm to 50 nm, dispersed in water are utilized. The CFD numerical results indicate that the elliptical tube can enhance heat transfer and friction factor by approximately 9% and 6% than the circular tube respectively. The results show that the Nusselt number and friction factor increase with decreasing diameters but increasing volume concentrations of nanoparticles.
PAPER REVISED: 2013-10-10
PAPER ACCEPTED: 2013-12-15
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  1. Das, S.K.,Choi, S.U. S.,Yu, W., Pradeep, Nanofluids Science and Technology. John Wiley & Sons, Inc. 2007
  2. Moghari, R. M., Two phase mixed convection Al2O3-water nanofluid flow in an elliptical tube, Int J. of Multiphase Flow, 3 (2011), pp.585-595
  3. Shariata, M., Akbarinia, A., Nezhad, A. H., Behzadmehra, A., Laur, R., Numerical study of two phase laminar mixed convection nanofluid in elliptic ducts, Applied Thermal Engineering, 31 (2011) pp. 2348-2359
  4. Puli,U., Rajvanshi, A.K., An image analysis technique for determination of void fraction in sub cooled flow boiling of water in horizontal elliptical tube at high pressures, Int.J. of Heat and Fluid Flow, 38 (2012), pp. 180-189
  5. Jawarneh, A.M., Heat Transfer Enhancement in Swirl Elliptical tube Flows, 5th WSEAS Int. Conf. on ENVIRONMENT, ECOSYSTEMS and DEVELOPMENT, Tenerife, Spain, (2007)
  6. Heris, S.Z., Convective Heat Transfer of a Cu/WATER Nanofluid Flowing through a Circular Tube, Experimental Heat Transfer, 22 (2009), pp.217-227
  7. Pak, B.C., Cho, Y.I., Hydrodynamic and Heat Transfer Study of Dispersed Fluids with Submicron Metallic Oxide Particles, Experimental Heat Transfer, 11 (1998), pp.151-171
  8. Sharma, K.V., Sarma, P.K., Azmi, W.H., Mamat, R., Kadirgama, K., Correlations to Predict Friction and Forced Convection Heat Transfer Coefficients of Water Based Nanofluids for Turbulent Flow in a Tube, IJMNTFTP 3, (2010), pp.1-25
  9. Kumar, P., A CFD Study of Heat Transfer Enhancement in Pipe Flow with Al2O3 Nanofluid, World Academy of Science, Engineering and Technology 57 (2011), pp.746-750 2011
  10. Bianco, V., Numerical Investigation on Nanofluids Turbulent Convection Heat Transfer Inside a Circular Tube, Int. J. of Thermal Sciences, 50 (2011), pp.341-349
  11. Sundar L.S., Sharma, K.V., Turbulent Heat Transfer and Friction Factor of Al2O3 Nanofluid in Circular Tube with Twisted Tape Inserts, Inter. J. Heat and Mass Transfer, 53 (2010), pp.1409 - 1416
  12. Durmus, A., Durmus, A., Esen, M., Investigation of heat transfer and pressure drop in a concentric heat exchanger with snail entrance, Applied Thermal Engineering, 22 (2002), pp. 321-332
  13. Bergles, A.E., Heat transfer enhancement the encouragement and accommodation of high heat fluxes, Transaction ASME, Journal Heat Transfer, 119 (1995) pp. 8-19
  14. Yildiz, C., Bicer,Y., Pehlivan,D., Effect of twisted strips on heat transfer and pressure drop in heat exchangers, Energy Conversion and Management, 39 (1998) pp. 331-336
  15. Manglik, R.M., Bergles, A.E., Heat transfer and pressure drop correlations for twisted-tape inserts in isothermal tubes: part II-transition and turbulent flows, Enhanced Heat Transfer, Transaction ASME, Journal Heat Transfer, 202 (1992), pp. 99-106
  16. Sarma, P.K., Subramanyam, T., Kishore, P.S., Dharma, R.V., Kakac, S., Laminar convective heat transfer with twisted tape inserts in a tube, Int. J. of Thermal Sciences, 42 (2003) pp.821-828
  17. Duangthongsuk, W., Wongwises, S., an Experimental Study on The Heat Transfer Performance and Pressure Drop of TiO2-water nanofluids flowing under a Turbulent Flow Regime, Int. J. of Heat and Mass Transfer, 53 (2010), pp.334-344.
  18. Prajapati, O. S., Effect of Al2O3-Water Nanofluids In Convective Heat Transfer, Int. J. of Nano science, 1 (2012), pp. 1-4
  19. Kittur, B.G., On the Forced Convective Flow between Two Corrugated Cylinders, Adv. Theor. Appl. Mech., 3 (2010), pp.491 - 506
  20. Bozorgan,N., Mafi, M., Bozorgan, N., Performance Evaluation of AI2O3/Water Nanofluid as Coolant in a Double-Tube Heat Exchanger Flowing under a Turbulent Flow Regime, Hindawi Publishing Corporation Advances in Mechanical Engineering, (2012), Article ID 891382, pp.1-8
  21. Demir, H., Dalkilic, A.S., Kürekci, N.A., Duangthongsuk, W., Wongwises, S., Numerical investigation on the single phase forced convection heat transfer characteristics of TiO2 nanofluids in a double-tube counter flow heat exchanger, Int. Comm. in Heat and Mass Transfer 38 (2011), pp. 218-228
  22. Luciu, R.S., Mateescu, T., Cotorobai, V., and Mare, T., Nusselt Number and Convection Heat Transfer Coefficient for a Coaxial Heat Exchanger Using Al2O3-water ph=5 nanofluid, Bul. Inst. Polit. Ias¸i, t. LV (LIX), f. 2, (2009)
  23. Heris, S. Z., Talaii, E., Noie, S. H., CuO-Water Nanofluid Heat Transfer Through Triangular Ducts, Iranian Journal of Chemical Engineering, 9, (2012), IAChE.
  24. Bejan A. Convection Heat Transfer. 3rd edition, John Wiley & Sons, Inc.2004
  25. Fluent Incorporated, "Fluent 6.2 User Manual," 2006.

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