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Al2O3-based nanofluids: a review.

Sridhara V, Satapathy LN - Nanoscale Res Lett (2011)

Bottom Line: These suspended nanoparticles can change the transport and thermal properties of the base fluid.As can be seen from the literature, extensive research has been carried out in alumina-water and CuO-water systems besides few reports in Cu-water-, TiO2-, zirconia-, diamond-, SiC-, Fe3O4-, Ag-, Au-, and CNT-based systems.The Al2O3 nanoparticles varied in the range of 13 to 302 nm to prepare nanofluids, and the observed enhancement in the thermal conductivity is 2% to 36%.

View Article: PubMed Central - HTML - PubMed

Affiliation: Ceramic Technological Institute, BHEL, Malleswaram Complex, Bangalore 560012, India. satpathy@bhelepd.com.

ABSTRACT
Ultrahigh performance cooling is one of the important needs of many industries. However, low thermal conductivity is a primary limitation in developing energy-efficient heat transfer fluids that are required for cooling purposes. Nanofluids are engineered by suspending nanoparticles with average sizes below 100 nm in heat transfer fluids such as water, oil, diesel, ethylene glycol, etc. Innovative heat transfer fluids are produced by suspending metallic or nonmetallic nanometer-sized solid particles. Experiments have shown that nanofluids have substantial higher thermal conductivities compared to the base fluids. These suspended nanoparticles can change the transport and thermal properties of the base fluid. As can be seen from the literature, extensive research has been carried out in alumina-water and CuO-water systems besides few reports in Cu-water-, TiO2-, zirconia-, diamond-, SiC-, Fe3O4-, Ag-, Au-, and CNT-based systems. The aim of this review is to summarize recent developments in research on the stability of nanofluids, enhancement of thermal conductivities, viscosity, and heat transfer characteristics of alumina (Al2O3)-based nanofluids. The Al2O3 nanoparticles varied in the range of 13 to 302 nm to prepare nanofluids, and the observed enhancement in the thermal conductivity is 2% to 36%.

No MeSH data available.


Related in: MedlinePlus

Effect of pH on thermal conductivity of water-based Al2O3 nanofluids. pH = 11.5 [16]; pH = 7.0 [16]; pH = 4.0 [16].
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Figure 9: Effect of pH on thermal conductivity of water-based Al2O3 nanofluids. pH = 11.5 [16]; pH = 7.0 [16]; pH = 4.0 [16].

Mentions: Xie et al. [16] prepared various suspensions containing Al2O3 nanoparticles with specific surface areas in a range of 5 to 124 m2/g, and their thermal conductivities were measured using a transient hot-wire method at a pH range of 2 to 11.5. It was noted that the nanoparticle suspensions, containing a small amount of Al2O3, have substantially higher thermal conductivity than the base fluid, with the enhancement increasing with the volume fraction of Al2O3. The enhanced thermal conductivity increases with an increase in the difference between the pH value of aqueous suspension and the isoelectric point of the Al2O3 particle. The enhancement observed for 60.4-nm-sized particle between 1.8 and 5 vol.% is 7% to 21%. The effect of pH on thermal conductivity of water-based Al2O3 nanofluids is shown in Figure 9.


Al2O3-based nanofluids: a review.

Sridhara V, Satapathy LN - Nanoscale Res Lett (2011)

Effect of pH on thermal conductivity of water-based Al2O3 nanofluids. pH = 11.5 [16]; pH = 7.0 [16]; pH = 4.0 [16].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211876&req=5

Figure 9: Effect of pH on thermal conductivity of water-based Al2O3 nanofluids. pH = 11.5 [16]; pH = 7.0 [16]; pH = 4.0 [16].
Mentions: Xie et al. [16] prepared various suspensions containing Al2O3 nanoparticles with specific surface areas in a range of 5 to 124 m2/g, and their thermal conductivities were measured using a transient hot-wire method at a pH range of 2 to 11.5. It was noted that the nanoparticle suspensions, containing a small amount of Al2O3, have substantially higher thermal conductivity than the base fluid, with the enhancement increasing with the volume fraction of Al2O3. The enhanced thermal conductivity increases with an increase in the difference between the pH value of aqueous suspension and the isoelectric point of the Al2O3 particle. The enhancement observed for 60.4-nm-sized particle between 1.8 and 5 vol.% is 7% to 21%. The effect of pH on thermal conductivity of water-based Al2O3 nanofluids is shown in Figure 9.

Bottom Line: These suspended nanoparticles can change the transport and thermal properties of the base fluid.As can be seen from the literature, extensive research has been carried out in alumina-water and CuO-water systems besides few reports in Cu-water-, TiO2-, zirconia-, diamond-, SiC-, Fe3O4-, Ag-, Au-, and CNT-based systems.The Al2O3 nanoparticles varied in the range of 13 to 302 nm to prepare nanofluids, and the observed enhancement in the thermal conductivity is 2% to 36%.

View Article: PubMed Central - HTML - PubMed

Affiliation: Ceramic Technological Institute, BHEL, Malleswaram Complex, Bangalore 560012, India. satpathy@bhelepd.com.

ABSTRACT
Ultrahigh performance cooling is one of the important needs of many industries. However, low thermal conductivity is a primary limitation in developing energy-efficient heat transfer fluids that are required for cooling purposes. Nanofluids are engineered by suspending nanoparticles with average sizes below 100 nm in heat transfer fluids such as water, oil, diesel, ethylene glycol, etc. Innovative heat transfer fluids are produced by suspending metallic or nonmetallic nanometer-sized solid particles. Experiments have shown that nanofluids have substantial higher thermal conductivities compared to the base fluids. These suspended nanoparticles can change the transport and thermal properties of the base fluid. As can be seen from the literature, extensive research has been carried out in alumina-water and CuO-water systems besides few reports in Cu-water-, TiO2-, zirconia-, diamond-, SiC-, Fe3O4-, Ag-, Au-, and CNT-based systems. The aim of this review is to summarize recent developments in research on the stability of nanofluids, enhancement of thermal conductivities, viscosity, and heat transfer characteristics of alumina (Al2O3)-based nanofluids. The Al2O3 nanoparticles varied in the range of 13 to 302 nm to prepare nanofluids, and the observed enhancement in the thermal conductivity is 2% to 36%.

No MeSH data available.


Related in: MedlinePlus