Abstract
Here we show through an order-of-magnitude analysis that the enhancement in the effective thermal conductivity of nanofluids is due mainly to the localized convection caused by the Brownian movement of the nanoparticles. We also introduce a convective-conductive model which accurately captures the effects of particle size, choice of base liquid, thermal interfacial resistance between the particles and liquid temperature, etc. This model is a combination of the Maxwell-Garnett (MG) conduction model and the convection caused by the Brownian movement of the nanoparticles, and reduces to the MG model for large particle sizes. The model is in good agreement with data on water ethylene glycol, and oil-based nanofluids, and shows that the lighter the nanoparticles, the greater the convection effect in the liquid, regardless of the thermal conductivity of the nanoparticle.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 588-595 |
| Number of pages | 8 |
| Journal | Journal of Heat Transfer |
| Volume | 128 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2006 |
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Keywords
- Brownian motion
- Colloid
- Nanofluid
- Nanoscale heat transfer
- Thermal conductivity
ASJC Scopus subject areas
- Mechanical Engineering
- Physical and Theoretical Chemistry
- Fluid Flow and Transfer Processes
Cite this
Brownian-motion-based convective-conductive model for the effective thermal conductivity of nanofluids. / Prasher, Ravi; Bhattacharya, Prajesh; Phelan, Patrick.
In: Journal of Heat Transfer, Vol. 128, No. 6, 06.2006, p. 588-595.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Brownian-motion-based convective-conductive model for the effective thermal conductivity of nanofluids
AU - Prasher, Ravi
AU - Bhattacharya, Prajesh
AU - Phelan, Patrick
PY - 2006/6
Y1 - 2006/6
N2 - Here we show through an order-of-magnitude analysis that the enhancement in the effective thermal conductivity of nanofluids is due mainly to the localized convection caused by the Brownian movement of the nanoparticles. We also introduce a convective-conductive model which accurately captures the effects of particle size, choice of base liquid, thermal interfacial resistance between the particles and liquid temperature, etc. This model is a combination of the Maxwell-Garnett (MG) conduction model and the convection caused by the Brownian movement of the nanoparticles, and reduces to the MG model for large particle sizes. The model is in good agreement with data on water ethylene glycol, and oil-based nanofluids, and shows that the lighter the nanoparticles, the greater the convection effect in the liquid, regardless of the thermal conductivity of the nanoparticle.
AB - Here we show through an order-of-magnitude analysis that the enhancement in the effective thermal conductivity of nanofluids is due mainly to the localized convection caused by the Brownian movement of the nanoparticles. We also introduce a convective-conductive model which accurately captures the effects of particle size, choice of base liquid, thermal interfacial resistance between the particles and liquid temperature, etc. This model is a combination of the Maxwell-Garnett (MG) conduction model and the convection caused by the Brownian movement of the nanoparticles, and reduces to the MG model for large particle sizes. The model is in good agreement with data on water ethylene glycol, and oil-based nanofluids, and shows that the lighter the nanoparticles, the greater the convection effect in the liquid, regardless of the thermal conductivity of the nanoparticle.
KW - Brownian motion
KW - Colloid
KW - Nanofluid
KW - Nanoscale heat transfer
KW - Thermal conductivity
UR - http://www.scopus.com/inward/record.url?scp=33745815300&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33745815300&partnerID=8YFLogxK
U2 - 10.1115/1.2188509
DO - 10.1115/1.2188509
M3 - Article
VL - 128
SP - 588
EP - 595
JO - Journal of Heat Transfer
JF - Journal of Heat Transfer
SN - 0022-1481
IS - 6
ER -