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Toward nanofluids of ultra-high thermal conductivity.

Wang L, Fan J - Nanoscale Res Lett (2011)

Bottom Line: The success of developing nanofluids of superior conductivity depends thus very much on our understanding and manipulation of the morphology and the coupled transport.Nanofluids with conductivity of upper Hashin-Shtrikman (H-S) bound can be obtained by manipulating particles into an interconnected configuration that disperses the base fluid and thus significantly enhancing the particle-fluid interfacial energy transport.While the direct contributions of ordered liquid layer and particle Brownian motion to the nanofluid conductivity are negligible, their indirect effects can be significant via their influence on the particle morphology and/or the coupled transport.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong. lqwang@hku.hk.

ABSTRACT
The assessment of proposed origins for thermal conductivity enhancement in nanofluids signifies the importance of particle morphology and coupled transport in determining nanofluid heat conduction and thermal conductivity. The success of developing nanofluids of superior conductivity depends thus very much on our understanding and manipulation of the morphology and the coupled transport. Nanofluids with conductivity of upper Hashin-Shtrikman (H-S) bound can be obtained by manipulating particles into an interconnected configuration that disperses the base fluid and thus significantly enhancing the particle-fluid interfacial energy transport. Nanofluids with conductivity higher than the upper H-S bound could also be developed by manipulating the coupled transport among various transport processes, and thus the nature of heat conduction in nanofluids. While the direct contributions of ordered liquid layer and particle Brownian motion to the nanofluid conductivity are negligible, their indirect effects can be significant via their influence on the particle morphology and/or the coupled transport.

No MeSH data available.


Related in: MedlinePlus

Variations of (ke)with/(ke)without with ηφ and dP/(2h).
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Figure 3: Variations of (ke)with/(ke)without with ηφ and dP/(2h).

Mentions: where η = (kp - kf)/(kp + 2kf). The variation of (ke)with/(ke)without with ηφ and dp/2h is illustrated in Figure 3, showing that the liquid-layering effect is important only when ηφ is large and dp/2h is small. This is normally not the case for practical nanofluids. For Cu-in-water nanofluids (η ≈ 1), for example, (ke)with/(ke)without ≈ 1.005 with φ = 0.5% and dp = 10 nm.


Toward nanofluids of ultra-high thermal conductivity.

Wang L, Fan J - Nanoscale Res Lett (2011)

Variations of (ke)with/(ke)without with ηφ and dP/(2h).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211204&req=5

Figure 3: Variations of (ke)with/(ke)without with ηφ and dP/(2h).
Mentions: where η = (kp - kf)/(kp + 2kf). The variation of (ke)with/(ke)without with ηφ and dp/2h is illustrated in Figure 3, showing that the liquid-layering effect is important only when ηφ is large and dp/2h is small. This is normally not the case for practical nanofluids. For Cu-in-water nanofluids (η ≈ 1), for example, (ke)with/(ke)without ≈ 1.005 with φ = 0.5% and dp = 10 nm.

Bottom Line: The success of developing nanofluids of superior conductivity depends thus very much on our understanding and manipulation of the morphology and the coupled transport.Nanofluids with conductivity of upper Hashin-Shtrikman (H-S) bound can be obtained by manipulating particles into an interconnected configuration that disperses the base fluid and thus significantly enhancing the particle-fluid interfacial energy transport.While the direct contributions of ordered liquid layer and particle Brownian motion to the nanofluid conductivity are negligible, their indirect effects can be significant via their influence on the particle morphology and/or the coupled transport.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong. lqwang@hku.hk.

ABSTRACT
The assessment of proposed origins for thermal conductivity enhancement in nanofluids signifies the importance of particle morphology and coupled transport in determining nanofluid heat conduction and thermal conductivity. The success of developing nanofluids of superior conductivity depends thus very much on our understanding and manipulation of the morphology and the coupled transport. Nanofluids with conductivity of upper Hashin-Shtrikman (H-S) bound can be obtained by manipulating particles into an interconnected configuration that disperses the base fluid and thus significantly enhancing the particle-fluid interfacial energy transport. Nanofluids with conductivity higher than the upper H-S bound could also be developed by manipulating the coupled transport among various transport processes, and thus the nature of heat conduction in nanofluids. While the direct contributions of ordered liquid layer and particle Brownian motion to the nanofluid conductivity are negligible, their indirect effects can be significant via their influence on the particle morphology and/or the coupled transport.

No MeSH data available.


Related in: MedlinePlus