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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.


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Effect of concentration on thermal conductivity of Al2O3-based nanofluids. Water NFs, φ% = 1.30-4.30 [15]; water NFs, φ% = 1.00-4.30 [1]; EG NFs, φ% = 1.00-5.00 [1]; water NFs, φ% = 3.00-5.00 [8]; EG NFs, φ% = 1.80-5.00 [16]; EG NFs, φ% = 1.00-5.00 [18]; water NFs, φ% = 1.00-4.00 [7]; water NFs, φ% = 2.00-10.00 [13]; EG NFs, φ% = 1.00-4.00 [11]; water NFs, φ% = 0.30-1.00 [17]; water NFs, φ% = 2.50-7.50 [14]; water NFs, φ% = 0.01-0.20 [19].
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Figure 1: Effect of concentration on thermal conductivity of Al2O3-based nanofluids. Water NFs, φ% = 1.30-4.30 [15]; water NFs, φ% = 1.00-4.30 [1]; EG NFs, φ% = 1.00-5.00 [1]; water NFs, φ% = 3.00-5.00 [8]; EG NFs, φ% = 1.80-5.00 [16]; EG NFs, φ% = 1.00-5.00 [18]; water NFs, φ% = 1.00-4.00 [7]; water NFs, φ% = 2.00-10.00 [13]; EG NFs, φ% = 1.00-4.00 [11]; water NFs, φ% = 0.30-1.00 [17]; water NFs, φ% = 2.50-7.50 [14]; water NFs, φ% = 0.01-0.20 [19].

Mentions: The effect of volume concentration on Al2O3-based nanofluids is shown in Figure 1. The researchers used different sizes of Al2O3 nanoparticles at different temperatures in water and ethylene glycol with particle volume concentration mostly less than 5% with few exceptions [13,14]. The maximum enhancement in thermal conductivity observed for 4 vol.% load in the case of water-based nanofluid was 32% [15] and in the case of ethylene glycol-based nanofluid was 30% [16], respectively. Hwang et al. [17] observed a 4% enhancement in thermal conductivity at 1 vol.% concentration; the observed enhancement was more compared to other researchers at same the volume fraction of solids [1,11,18]. Lee et al. [19] observed a 2% enhancement at a lower volume percent for 35-nm-sized Al2O3 particles. In the case of Li and Peterson [13], the thermal conductivity enhancement was decreased as concentration increased from 6% to 10%, but in the case of Timofeeva et al. [14], the thermal conductivity was increased as concentration increased from 2% to 10% even though the particle size was almost the same in both the cases.


Al2O3-based nanofluids: a review.

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

Effect of concentration on thermal conductivity of Al2O3-based nanofluids. Water NFs, φ% = 1.30-4.30 [15]; water NFs, φ% = 1.00-4.30 [1]; EG NFs, φ% = 1.00-5.00 [1]; water NFs, φ% = 3.00-5.00 [8]; EG NFs, φ% = 1.80-5.00 [16]; EG NFs, φ% = 1.00-5.00 [18]; water NFs, φ% = 1.00-4.00 [7]; water NFs, φ% = 2.00-10.00 [13]; EG NFs, φ% = 1.00-4.00 [11]; water NFs, φ% = 0.30-1.00 [17]; water NFs, φ% = 2.50-7.50 [14]; water NFs, φ% = 0.01-0.20 [19].
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Effect of concentration on thermal conductivity of Al2O3-based nanofluids. Water NFs, φ% = 1.30-4.30 [15]; water NFs, φ% = 1.00-4.30 [1]; EG NFs, φ% = 1.00-5.00 [1]; water NFs, φ% = 3.00-5.00 [8]; EG NFs, φ% = 1.80-5.00 [16]; EG NFs, φ% = 1.00-5.00 [18]; water NFs, φ% = 1.00-4.00 [7]; water NFs, φ% = 2.00-10.00 [13]; EG NFs, φ% = 1.00-4.00 [11]; water NFs, φ% = 0.30-1.00 [17]; water NFs, φ% = 2.50-7.50 [14]; water NFs, φ% = 0.01-0.20 [19].
Mentions: The effect of volume concentration on Al2O3-based nanofluids is shown in Figure 1. The researchers used different sizes of Al2O3 nanoparticles at different temperatures in water and ethylene glycol with particle volume concentration mostly less than 5% with few exceptions [13,14]. The maximum enhancement in thermal conductivity observed for 4 vol.% load in the case of water-based nanofluid was 32% [15] and in the case of ethylene glycol-based nanofluid was 30% [16], respectively. Hwang et al. [17] observed a 4% enhancement in thermal conductivity at 1 vol.% concentration; the observed enhancement was more compared to other researchers at same the volume fraction of solids [1,11,18]. Lee et al. [19] observed a 2% enhancement at a lower volume percent for 35-nm-sized Al2O3 particles. In the case of Li and Peterson [13], the thermal conductivity enhancement was decreased as concentration increased from 6% to 10%, but in the case of Timofeeva et al. [14], the thermal conductivity was increased as concentration increased from 2% to 10% even though the particle size was almost the same in both the cases.

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