Electrical conductivity of ceramic and metallic nanofluids

Sarojini, K.G. Kalpana; Manoj, Siva V.; Singh, Pawan Kumar; Pradeep, Thalappil; Das, Sarit K.

doi:10.1016/j.colsurfa.2012.10.010

Cited by 139 publications

(88 citation statements)

References 25 publications

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“…Other researchers have shown that the thermal properties of nanofluid are also dependent on temperature and the particle size, the use of dispersant and type of dispersion assist mechanism used for the preparation [14][15][16]. Research works have also been carried out on the electrical conductivity of nanofluids [17][18][19], rheology and viscosity of nanofluids [20,21], and convective heat transfer using nanofluids [12,22]. Mostly investigated thermophysical properties of nanofluids are the thermal conductivity and the convective heat transfer coefficient.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation and model development for effective viscosity of Al2O3–glycerol nanofluids by using dimensional analysis and GMDH-NN methods

Sharifpur

Adio

Meyer

2015

International Communications in Heat and Mass Transfer

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Nanofluids are new heat transfer fluids which aimed to improve the poor heat removal efficiency of conventional heat transfer fluids. The dispersion of nanoparticles into traditional heat transfer fluids such as ethylene glycol, glycerol, engine oil, gear oil and water has become widely applicable in engineering systems because of their superior heat transfer properties. However, viscosity increase due to nanoparticle dispersion is an issue which needs attention and proper experimental investigation. Therefore, in this study, it is experimentally optimized the two-step preparation procedure for Al 2 O 3 -glycerol nanofluids consisting of 19, 139 and 160 nm particle sizes, and then studied the effective viscosity between 20-70 o C for the range of 0 to 5% volume fractions. The nanofluids' viscosity showed a characteristic increase as volume fraction increases; decrease as the working temperature increases; and the smallest nanoparticles showed the highest shear resistance. Based on the available experimental data, an empirical correlation has been offered using dimensional analysis. Thereafter, a hybrid neural network based on the group method of data handling (GMDH-NN) has been employed for modeling the effective viscosity of Al 2 O 3 -glycerol nanofluid. The correlations obtained from both modeling procedures showed higher accuracy in the prediction of the present experimental data when compared to most cited models from the open literature.

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Section: Introductionmentioning

confidence: 99%

Experimental investigation and model development for effective viscosity of Al2O3–glycerol nanofluids by using dimensional analysis and GMDH-NN methods

Sharifpur

Adio

Meyer

2015

International Communications in Heat and Mass Transfer

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“…Previous studies have suggested various models [63][64][65][66] for the effective electrical conductivity of nanofluid, but none of them always provides good predictions. Therefore, in this paper, based on the literature review [59][60][61][62][67][68][69], we consider σ n f = 4.0 S/m (a constant).…”

Section: Lorentz Forcementioning

confidence: 99%

Effects of Anisotropic Thermal Conductivity and Lorentz Force on the Flow and Heat Transfer of a Ferro-Nanofluid in a Magnetic Field

Yan

Massoudi

et al. 2017

Energies

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Abstract:In this paper, we study the effects of the Lorentz force and the induced anisotropic thermal conductivity due to a magnetic field on the flow and the heat transfer of a ferro-nanofluid. The ferro-nanofluid is modeled as a single-phase fluid, where the viscosity depends on the concentration of nanoparticles; the thermal conductivity shows anisotropy due to the presence of the nanoparticles and the external magnetic field. The anisotropic thermal conductivity tensor, which depends on the angle of the applied magnetic field, is suggested considering the principle of material frame indifference according to Continuum Mechanics. We study two benchmark problems: the heat conduction between two concentric cylinders as well as the unsteady flow and heat transfer in a rectangular channel with three heated inner cylinders. The governing equations are made dimensionless, and the flow and the heat transfer characteristics of the ferro-nanofluid with different angles of the magnetic field, Hartmann number, Reynolds number and nanoparticles concentration are investigated systematically. The results indicate that the temperature field is strongly influenced by the anisotropic behavior of the nanofluids. In addition, the magnetic field may enhance or deteriorate the heat transfer performance (i.e., the time-spatially averaged Nusselt number) in the rectangular channel depending on the situations.

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“…The electrical conductivity requirement, which is as low as 1.5 to 2 S/cm [39] and 5 S/cm at 20 C [37], needs to be maintained over time. A few researchers have investigated the effect of electrical conductivity on various types of nanofluids [40][41][42][43][44][45][46][47][48][49][50][51]. Wong and Kurma [40] studied the effect of volume concentration on the electrical conductivity of Al 2 O 3 nanofluid.…”

Section: Challenges Of Nanofluids In Pemfc Electrical Conductivitymentioning

confidence: 99%

A Review of Nanofluid Adoption in Polymer Electrolyte Membrane (Pem) Fuel Cells as an Alternative Coolant

et al. 2015

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Continuous need for the optimum conversion efficiency of polymer electrolyte membrane fuel cell (PEMFC) operation has triggered varieties of advancements, namely in the thermal management engineering scope. Excellent heat dissipation is correlated with higher performance of a fuel cell, thus increasing its conversion efficiency. This study reveals the potential advancement in thermal engineering of a fuel cell cooling system with respect to nanofluid technology. Nanofluids are seen as a potential evolution of nanotechnology hybridization with the fuel cell serving as a cooling medium. The available literature on the thermophysical properties of potential nanofluids, especially on the electrical conductivity property, has been discussed. The lack of electrical conductivity data for various nanofluids in open literature was another challenge in the application of nanofluids in fuel cells. Unlike in any other thermal management system, a nanofluid in a fuel cell is dealt with using a thermoelectrically active environment. The main challenge in nanofluid adoption in fuel cells was the formulation of a suitable nanofluid coolant with heat transfer enhancement, as compared to its base fluid, but still complying with the strict limits of electrical conductivity as low as 2 S/cm and several other restrictions discussed by the researchers. It is concluded that a nanofluid in PEMFC is advantageous in terms of both heat transfer and simplification of the cooling system through radiator size reduction and potential elimination of the deionizer as compared to the current PEMFC cooling system. However, there are challenges that need to be well addressed, especially in the electrical conductivity requirement.

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Electrical conductivity of ceramic and metallic nanofluids

Cited by 139 publications

References 25 publications

Experimental investigation and model development for effective viscosity of Al2O3–glycerol nanofluids by using dimensional analysis and GMDH-NN methods

Experimental investigation and model development for effective viscosity of Al2O3–glycerol nanofluids by using dimensional analysis and GMDH-NN methods

Effects of Anisotropic Thermal Conductivity and Lorentz Force on the Flow and Heat Transfer of a Ferro-Nanofluid in a Magnetic Field

A Review of Nanofluid Adoption in Polymer Electrolyte Membrane (Pem) Fuel Cells as an Alternative Coolant

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