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 paper, an experimental study has been conducted on the rheological behavior of water-EG coolant in presence of MgO-MWCNTs hybrid nanomaterials.
70 citations
TL;DR: In this article, the impact of higher-order chemical processing and dissipation of viscous on nanofluid along with a continuously stretching porous sheet is taken, and the level of raising thermal conductivity and the output of transferring the heat on nano-fluid is observed.
Abstract: In this paper, the groundwork of some thermophysical properties of higher-order chemical processing and dissipation of viscous on nanofluid along with a continuously stretching porous sheet is taken. The porous medium is considered with two space coordinates, laminar, time-invariant, MHD incompressible Newtonian nanofluid. The equations are framed to govern the fluid flow as coupled equations involving nonlinear partial derivatives. The impacts of electric and magnetic fields on nanofluid with viscous dissipation in the presence of higher-order chemical reaction, analyzing conservation of momentum and energy, is the novelty of the problem. The level of raising thermal conductivity and the output of transferring the heat on nanofluid is observed. Finally, the governing equations involving partial derivatives have complied with nonlinear ordinary differential equations. The transformations are subjected to the similarity variable used to solve these equations. Approximate solutions are obtained using a numerical method of the Runge-Kutta-Felburg method with shooting technique. The effects of emerging parameters K r , E r , λ , N t , δ , N b are porous, electric, mixed convection, thermophoresis, chemical process and, Brownian motion, and non-dimensional numbers such as Hartmann, Prandtl, Schmidt, and Eckert are extensively explained. The electrically conducting nanofluid flow for velocity fluid, temperature fluid and, nanoparticles concentration volume fraction fluid with transferring heat, Nusselt, and transferring mass, Sherwood number are examined with graphical representation. The Lorentz resistive force due to the applied strength of electric develops the thickness of boundary layers of momentum and thermal regions. This helps to cool the electronic systems and radiators. The dimensionless Nusselt number diminishes with various values of thermophoresis and Brownian motion parameters as a dependent function of Hartmann, electric number, and homogeneous chemical reaction parameter.
70 citations
TL;DR: In this article, the problem of magnetohydrodynamic (MHD) mixed convection flow of Cobalt-kerosene ferrofluid adjacent a non-isothermal wedge under the influence of thermal radiation and partial slip was addressed.
70 citations
TL;DR: In this paper, the mixed convection flow of non-Newtonian nanofluid over a stretching surface in presence of thermal radiation, heat source/sink and first order chemical reaction is addressed.
Abstract: The present study addresses the mixed convection flow of non-Newtonian nanofluid over a stretching surface in presence of thermal radiation, heat source/sink and first order chemical reaction. Casson fluid model is adopted in the present study. Magnetic field contribution is incorporated in the momentum equation whereas the aspects of nanoparticles are considered in the energy and concentration equations. Convective boundary conditions for both heat and mass transfer are utilized. Similarity transformations are employed to reduce the partial differential equations into ordinary differential equations. Series solutions of the resulting problem are obtained. Impacts of all the physical parameters on the velocity, temperature and concentration fields are analyzed graphically. Numerical values of different involved parameters for local skin friction coefficient, local Nusselt and Sherwood numbers are obtained and discussed.
70 citations
TL;DR: In this paper, the authors investigated the generation of entropy and transfer of heat during forced convection of a nanofluid through a partially-filled porous channel, where a fully developed flow in a channel with a central porous insert and under constant heat flux boundary condition was considered.
70 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