Experimental studies on heat transfer and friction factor characteristics of Al2O3/water nanofluid in a circular pipe under laminar flow with wire coil inserts

In this paper, fully developed laminar flow convective heat transfer and friction factor characteristics of Al{sub 2}O{sub 3}/water nanofluid flowing through a uniformly heated horizontal tube with and without wire coil inserts is presented. For this purpose, Al{sub 2}O{sub 3} nanoparticles of 43 nm size were synthesized, characterized and dispersed in distilled water to form stable suspension containing 0.1% volume concentration of nanoparticles. The Nusselt number in the fully developed region were measured and found to increase by 12.24% at Re = 2275 for plain tube with nanofluid compared to distilled water. Two wire coil inserts made of stainless steel with pitch ratios 2 and 3 were used which increased the Nusselt numbers by 15.91% and 21.53% respectively at Re = 2275 with nanofluid compared to distilled water. The better heat transfer performance of nanofluid with wire coil insert is attributed to the effects of dispersion or back-mixing which flattens the temperature distribution and make the temperature gradient between the fluid and wall steeper. The measured pressure loss with the use of nanofluids is almost equal to that of the distilled water. The empirical correlations developed for Nusselt number and friction factor in terms of Reynolds/Peclet number, pitch ratio andmore » volume concentration fits with the experimental data within {+-}15%. (author)« less

[1]  Seok Pil Jang,et al.  Flow and convective heat transfer characteristics of water-based Al2O3 nanofluids in fully developed laminar flow regime , 2009 .

[2]  Avtar Singh Ahuja,et al.  Augmentation of heat transport in laminar flow of polystyrene suspensions. I. Experiments and results , 1975 .

[3]  W. Roetzel,et al.  Conceptions for heat transfer correlation of nanofluids , 2000 .

[4]  Y. Xuan,et al.  Investigation on Convective Heat Transfer and Flow Features of Nanofluids , 2003 .

[5]  E. Grulke,et al.  Heat transfer properties of nanoparticle-in-fluid dispersions (nanofluids) in laminar flow , 2005 .

[6]  Seok Pil Jang,et al.  Effective viscosities and thermal conductivities of aqueous nanofluids containing low volume concentrations of Al2O3 nanoparticles , 2008 .

[7]  Young I Cho,et al.  HYDRODYNAMIC AND HEAT TRANSFER STUDY OF DISPERSED FLUIDS WITH SUBMICRON METALLIC OXIDE PARTICLES , 1998 .

[8]  Anupam Dewan,et al.  Review of passive heat transfer augmentation techniques , 2004 .

[9]  A. Ferrero,et al.  Measurement uncertainty , 2006, IEEE Instrumentation & Measurement Magazine.

[10]  C. T. Nguyen,et al.  Heat transfer enhancement using Al2O3–water nanofluid for an electronic liquid cooling system , 2007 .

[11]  Somchai Wongwises,et al.  Effect of thermophysical properties models on the predicting of the convective heat transfer coefficient for low concentration nanofluid , 2008 .

[12]  Sarit K. Das,et al.  Effect of particle size on the convective heat transfer in nanofluid in the developing region , 2009 .

[13]  Yulong Ding,et al.  Heat transfer of aqueous suspensions of carbon nanotubes (CNT nanofluids) , 2006 .

[14]  Somchai Wongwises,et al.  Heat transfer enhancement and pressure drop characteristics of TiO2–water nanofluid in a double-tube counter flow heat exchanger , 2009 .

[15]  S. Wongwises,et al.  Measurement of temperature-dependent thermal conductivity and viscosity of TiO2-water nanofluids , 2009 .

[16]  Saeed Zeinali Heris,et al.  EXPERIMENTAL INVESTIGATION OF CONVECTIVE HEAT TRANSFER OF AL2O3/WATER NANOFLUID IN CIRCULAR TUBE , 2007 .

[17]  Yulong Ding,et al.  Experimental investigation into convective heat transfer of nanofluids at the entrance region under laminar flow conditions , 2004 .

[18]  Haisheng Chen,et al.  Heat transfer and flow behaviour of aqueous suspensions of TiO2 nanoparticles (nanofluids) flowing upward through a vertical pipe , 2007 .

[19]  A. Viedma,et al.  Experimental study of heat transfer enhancement with wire coil inserts in laminar-transition-turbulent regimes at different Prandtl numbers , 2005 .

[20]  J. Maxwell.  A Treatise on Electricity and Magnetism , 1873, Nature.

[21]  J. Buongiorno,et al.  Experimental Investigation of Turbulent Convective Heat Transfer and Pressure Loss of Alumina/Water and Zirconia/Water Nanoparticle Colloids (Nanofluids) in Horizontal Tubes , 2008 .

[22]  W. Roetzel,et al.  TEMPERATURE DEPENDENCE OF THERMAL CONDUCTIVITY ENHANCEMENT FOR NANOFLUIDS , 2003 .

[23]  Chunqing Tan,et al.  Heat transfer and flow behaviour of aqueous suspensions of titanate nanotubes (nanofluids) , 2008 .