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Stability of nanofluids in quiescent and shear flow fields.

Witharana S, Chen H, Ding Y - Nanoscale Res Lett (2011)

Bottom Line: An experimental study was conducted to investigate the structural stability of ethylene glycol-based titanium dioxide nanoparticle suspensions (nanofluids) prepared by two-step method.Particle size and thermal conductivity measurements in quiescent state indicated the existence of aggregates and that they were stable in temperatures up to 60°C.These findings show directions to resolve controversies surrounding the underlying mechanisms of thermal conduction and convective heat transfer of nanofluids.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Particle Science and Engineering, University of Leeds, Leeds LS2 9JT, UK. pmsw@leeds.ac.uk.

ABSTRACT
An experimental study was conducted to investigate the structural stability of ethylene glycol-based titanium dioxide nanoparticle suspensions (nanofluids) prepared by two-step method. The effects of particle concentration, fluid temperature, shear rate and shear duration were examined. Particle size and thermal conductivity measurements in quiescent state indicated the existence of aggregates and that they were stable in temperatures up to 60°C. Shear stability tests suggested that the structure of nanoparticle aggregates was stable in a shear interval of 500-3000 s-1 measured over a temperature range of 20-60°C. These findings show directions to resolve controversies surrounding the underlying mechanisms of thermal conduction and convective heat transfer of nanofluids.

No MeSH data available.


Related in: MedlinePlus

Measured and predicted thermal conductivity.
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Figure 3: Measured and predicted thermal conductivity.

Mentions: The average enhancement for each concentration in Figure 2b is plotted in Figure 3 together with the predictions of classical Hamilton-Crosser (H-C) model based on well-dispersed particles [25] and modified H-C model [20] based on aggregated particles. The classical H-C model can be written as(1)


Stability of nanofluids in quiescent and shear flow fields.

Witharana S, Chen H, Ding Y - Nanoscale Res Lett (2011)

Measured and predicted thermal conductivity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211290&req=5

Figure 3: Measured and predicted thermal conductivity.
Mentions: The average enhancement for each concentration in Figure 2b is plotted in Figure 3 together with the predictions of classical Hamilton-Crosser (H-C) model based on well-dispersed particles [25] and modified H-C model [20] based on aggregated particles. The classical H-C model can be written as(1)

Bottom Line: An experimental study was conducted to investigate the structural stability of ethylene glycol-based titanium dioxide nanoparticle suspensions (nanofluids) prepared by two-step method.Particle size and thermal conductivity measurements in quiescent state indicated the existence of aggregates and that they were stable in temperatures up to 60°C.These findings show directions to resolve controversies surrounding the underlying mechanisms of thermal conduction and convective heat transfer of nanofluids.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Particle Science and Engineering, University of Leeds, Leeds LS2 9JT, UK. pmsw@leeds.ac.uk.

ABSTRACT
An experimental study was conducted to investigate the structural stability of ethylene glycol-based titanium dioxide nanoparticle suspensions (nanofluids) prepared by two-step method. The effects of particle concentration, fluid temperature, shear rate and shear duration were examined. Particle size and thermal conductivity measurements in quiescent state indicated the existence of aggregates and that they were stable in temperatures up to 60°C. Shear stability tests suggested that the structure of nanoparticle aggregates was stable in a shear interval of 500-3000 s-1 measured over a temperature range of 20-60°C. These findings show directions to resolve controversies surrounding the underlying mechanisms of thermal conduction and convective heat transfer of nanofluids.

No MeSH data available.


Related in: MedlinePlus