Investigation on Convective Heat Transfer and Flow Features of Nanofluids
01 Feb 2003-Journal of Heat Transfer-transactions of The Asme (American Society of Mechanical Engineers)-Vol. 125, Iss: 1, pp 151-155
TL;DR: In this article, an innovative new class of heat transfer fluids can be engineered by suspending metallic nanoparticles in conventional heat-transfer fluids, which are expected to exhibit high thermal conductivities compared to those of currently used heat transfer fluid, and they represent the best hope for enhancing heat transfer.
Abstract: Low thermal conductivity is a primary limitation in the development of energy-efficient heat transfer fluids that are required in many industrial applications. In this paper we propose that an innovative new class of heat transfer fluids can be engineered by suspending metallic nanoparticles in conventional heat transfer fluids. The resulting {open_quotes}nanofluids{close_quotes} are expected to exhibit high thermal conductivities compared to those of currently used heat transfer fluids, and they represent the best hope for enhancement of heat transfer. The results of a theoretical study of the thermal conductivity of nanofluids with copper nanophase materials are presented, the potential benefits of the fluids are estimated, and it is shown that one of the benefits of nanofluids will be dramatic reductions in heat exchanger pumping power.
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TL;DR: In this article, a single microchannel was investigated with pure water and nanofluid as the working fluids, and it was found that the boiling flow was always stable or quasi-stable with significantly reduced pressure drop and enhanced heat transfer.
68 citations
01 Jan 2003
TL;DR: In this article, the authors used nanofluid as the working medium for a disk-shaped miniature heat pipe (DMHP) and measured the thermal resistance of the DMHP.
Abstract: The present study used nanofluid as the working medium for a disk-shaped miniature heat pipe (DMHP) The nanofluid is a suspension with gold nanoparticles of an average diameter of 17 nm in an aqueous solution An experimental system was set up to measure the thermal resistance of the disk-shaped miniature heat pipe (DMHP) with both nanofluid and DI-water A mounting base is designed and integrated with the DMHP as a heat spreader for a laser diode TO can package The present mounting base is made of aluminum (6061 T6) The measured results show that the thermal resistance of the DMHP varies with the charge volume and the type of working medium At the same charge volume, a significant reduction in the thermal resistance of the DMHP can be found if nanofluid is used instead of DI-water
68 citations
TL;DR: In this article, the effects of chemical reaction and thermal radiation on the flow of a Williamson nanofluid over a convectively heated Riga plate with variable thickness were investigated.
68 citations
TL;DR: In this article, the stability of a non-Newtonian nanofluid saturated horizontal rotating porous layer subjected to thermal conductivity and viscosity variation is investigated using linear and nonlinear stability analyses.
Abstract: The stability of a non-Newtonian nanofluid saturated horizontal rotating porous layer subjected to thermal conductivity and viscosity variation is investigated using linear and nonlinear stability analyses. The model used for the non-Newtonian nanofluid includes the effects of Brownian motion and thermophoresis. The Darcy law for the non-Newtonian nanofluid of the Oldroyd type is used to model the momentum equation. The linear theory based on the normal mode method, and the criteria for both stationary and oscillatory modes are derived analytically. A weak nonlinear analysis based on the minimal representation of truncated Fourier series method containing only two terms is used to compute the concentration and thermal Nusselt numbers. The results obtained during the analysis are presented graphically.
68 citations
TL;DR: In this article, the effect of using hybrid water-based suspension on thermal behavior and hydrodynamic performance in a range of Reynolds number in the laminar regime is investigated.
Abstract: A numerical investigation of a laminar forced convection of different working fluids including pure water, various volume concentrations of a nanofluid (Al2O3 nanoparticles dispersed in water), and a hybrid water-based suspension of Al2O3 and Cu nanoparticles (which is a new advanced nanofluid with two kinds of nanoparticle materials) in a uniformly heated circular tube is accomplished. In this paper, the effect of using hybrid water-based suspension on thermal behavior and hydrodynamic performance in a range of Reynolds number in the laminar regime is investigated. Then, a comparison is made between the thermal and hydrodynamics behavior of the hybrid suspension with those of the nanofluid (with the same concentration) and the conventional one. It is observed that, for all Reynolds numbers studied, employing the hybrid suspension improves the heat transfer rate compared to pure water and the nanofluid. Nevertheless, it reveals an adverse effect on the wall shear stress and friction factor due to the pres...
68 citations
References
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Book•
01 Jan 1985
TL;DR: In this article, the physical concepts and methodologies of heat and mass transfer are explained for advanced undergraduate engineering majors, using a systematic method for problem solving and discusses the relationship of heat transfer to many important practical applications through examples and problems.
Abstract: This book, designed for advanced undergraduate engineering majors, explains the physical concepts and methodologies of heat and mass transfer. It uses a systematic method for problem solving and discusses the relationship of heat and mass transfer to many important practical applications through examples and problems. A and significant contribution is the extensive use of the First Law of thermodynamics.
4,113 citations
TL;DR: In this article, the authors used a Brookfield rotating viscometer to measure the viscosities of the dispersed fluids with γ-alumina (Al2O3) and titanium dioxide (TiO2) particles at a 10% volume concentration.
Abstract: Turbulent friction and heat transfer behaviors of dispersed fluids (i.e., uttrafine metallic oxide particles suspended in water) in a circular pipe were investigated experimentally. Viscosity measurements were also conducted using a Brookfield rotating viscometer. Two different metallic oxide particles, γ-alumina (Al2O3) and titanium dioxide (TiO2), with mean diameters of 13 and 27 nm, respectively, were used as suspended particles. The Reynolds and Prandtl numbers varied in the ranges l04-I05 and 6.5-12.3, respectively. The viscosities of the dispersed fluids with γ-Al2O3 and TiO2 particles at a 10% volume concentration were approximately 200 and 3 times greater than that of water, respectively. These viscosity results were significantly larger than the predictions from the classical theory of suspension rheology. Darcy friction factors for the dispersed fluids of the volume concentration ranging from 1% to 3% coincided well with Kays' correlation for turbulent flow of a single-phase fluid. The Nusselt n...
3,730 citations
3,019 citations
"Investigation on Convective Heat Tr..." refers background in this paper
...Hamilton and Crasser (1962) have developed a more elaborate model for the effective thermal conductivity of twocomponent mixtures as a function of the conductivity of the pure materials, the composition of the mixture, and the shape of the dispersed particles....
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TL;DR: In this paper, a transient hot-wire method was used to measure the thermal conductivity of a small amount of nanoparticles and the experimental results showed that these nanoparticles have substantially higher thermal conductivities than the same liquids without nanoparticles.
Abstract: Oxide nanofluids were produced and their thermal conductivities were measured by a transient hot-wire method. The experimental results show that these nanofluids, containing a small amount of nanoparticles, have substantially higher thermal conductivities than the same liquids without nanoparticles. Comparisons between experiments and the Hamilton and Crosser model show that the model can predict the thermal conductivity of nanofluids containing large agglomerated Al{sub 2}O{sub 3} particles. However, the model appears to be inadequate for nanofluids containing CuO particles. This suggests that not only particle shape but size is considered to be dominant in enhancing the thermal conductivity of nanofluids.
2,811 citations
TL;DR: In this article, the authors proposed two different approaches for deriving heat transfer correlation of the nanofluid, and investigated the mechanism of heat transfer enhancement of the nano-fluid.
2,355 citations