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Thermal conductivity and viscosity measurements of ethylene glycol-based Al2O3 nanofluids.

Pastoriza-Gallego MJ, Lugo L, Legido JL, Piñeiro MM - Nanoscale Res Lett (2011)

Bottom Line: The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction.Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available.These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, Campus Universitario s/n, E-36310, Vigo, Spain. mmpineiro@uvigo.es.

ABSTRACT
The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction. The thermal conductivity and viscosity were experimentally determined at temperatures ranging from 283.15 K to 323.15 K using an apparatus based on the hot-wire method and a rotational viscometer, respectively. It has been found that both thermal conductivity and viscosity increase with the concentration of nanoparticles, whereas when the temperature increases the viscosity diminishes and the thermal conductivity rises. Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available. New viscosity experimental data yield values more than twice larger than the base fluid. The influence of particle size on viscosity has been also studied, finding large differences that must be taken into account for any practical application. These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity.

No MeSH data available.


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Dynamic viscosities for both Al2O3/EG nanofluids versus temperature. S1 samples (a) and S2 samples (b). Experimental points at different volume fractions: EG (filled circle), 0.005 (empty circle), 0.010 (filled diamond), 0.015 (empty diamond), 0.021 (filled square), 0.031 (empty square), 0.048 (filled triangle), 0.066 (empty triangle), Vogel-Fulcher-Tammann equation (solid line).
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Figure 5: Dynamic viscosities for both Al2O3/EG nanofluids versus temperature. S1 samples (a) and S2 samples (b). Experimental points at different volume fractions: EG (filled circle), 0.005 (empty circle), 0.010 (filled diamond), 0.015 (empty diamond), 0.021 (filled square), 0.031 (empty square), 0.048 (filled triangle), 0.066 (empty triangle), Vogel-Fulcher-Tammann equation (solid line).

Mentions: Concentrations from 1.7% to 20% in weight fraction, corresponding to volume fractions from 0.005 to 0.065, were considered for nanofluids using S1 samples, while concentrations from 1.7% to 10% in weight fraction, corresponding to volume fractions from 0.005 to 0.03, were measured for the S2 samples. The viscosity decreases significantly with temperature, as usual, as represented in Figure 5.


Thermal conductivity and viscosity measurements of ethylene glycol-based Al2O3 nanofluids.

Pastoriza-Gallego MJ, Lugo L, Legido JL, Piñeiro MM - Nanoscale Res Lett (2011)

Dynamic viscosities for both Al2O3/EG nanofluids versus temperature. S1 samples (a) and S2 samples (b). Experimental points at different volume fractions: EG (filled circle), 0.005 (empty circle), 0.010 (filled diamond), 0.015 (empty diamond), 0.021 (filled square), 0.031 (empty square), 0.048 (filled triangle), 0.066 (empty triangle), Vogel-Fulcher-Tammann equation (solid line).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211279&req=5

Figure 5: Dynamic viscosities for both Al2O3/EG nanofluids versus temperature. S1 samples (a) and S2 samples (b). Experimental points at different volume fractions: EG (filled circle), 0.005 (empty circle), 0.010 (filled diamond), 0.015 (empty diamond), 0.021 (filled square), 0.031 (empty square), 0.048 (filled triangle), 0.066 (empty triangle), Vogel-Fulcher-Tammann equation (solid line).
Mentions: Concentrations from 1.7% to 20% in weight fraction, corresponding to volume fractions from 0.005 to 0.065, were considered for nanofluids using S1 samples, while concentrations from 1.7% to 10% in weight fraction, corresponding to volume fractions from 0.005 to 0.03, were measured for the S2 samples. The viscosity decreases significantly with temperature, as usual, as represented in Figure 5.

Bottom Line: The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction.Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available.These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity.

View Article: PubMed Central - HTML - PubMed

Affiliation: Departamento de Física Aplicada, Facultade de Ciencias, Universidade de Vigo, Campus Universitario s/n, E-36310, Vigo, Spain. mmpineiro@uvigo.es.

ABSTRACT
The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction. The thermal conductivity and viscosity were experimentally determined at temperatures ranging from 283.15 K to 323.15 K using an apparatus based on the hot-wire method and a rotational viscometer, respectively. It has been found that both thermal conductivity and viscosity increase with the concentration of nanoparticles, whereas when the temperature increases the viscosity diminishes and the thermal conductivity rises. Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available. New viscosity experimental data yield values more than twice larger than the base fluid. The influence of particle size on viscosity has been also studied, finding large differences that must be taken into account for any practical application. These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity.

No MeSH data available.


Related in: MedlinePlus