Journal of Nanoparticle Research

, Volume 11, Issue 6, pp 1501–1507

Comments on the effect of liquid layering on the thermal conductivity of nanofluids

Authors

  • Elham Doroodchi
    • Centre for Advanced Particle Processing, Chemical Engineering, Faculty of Engineering & Built EnvironmentThe University of Newcastle
  • Thomas Michael Evans
    • Faculty of ScienceThe Australian National University
    • Centre for Energy, Chemical Engineering, Faculty of Engineering & Built EnvironmentThe University of Newcastle
Brief Communication

DOI: 10.1007/s11051-008-9522-9

Cite this article as:
Doroodchi, E., Evans, T.M. & Moghtaderi, B. J Nanopart Res (2009) 11: 1501. doi:10.1007/s11051-008-9522-9

Abstract

This article provides critical examinations of two mathematical models that have been developed in recent years to describe the impact of nano-layering on the enhancement of the effective thermal conductivity of nanofluids. Discrepancy between the two models is found to be an artefact of an incorrect derivation used in one of the models. With correct formulation, both models predict effective thermal conductivity enhancements that are not significantly greater than those predicted by classical Maxwell theory. This study indicates that nano-layering by itself is unable to account for the effective thermal conductivity enhancements observed in nanofluids.

Keywords

Nanofluids Thermal conductivity Conductivity enhancement Fluid layering Nanoparticles Modeling and simulation

Nomenclature

k

Thermal conductivity

a

Nanoparticle radius

r

Radial position in spherical coordinates

h

Nanolayer thickness

V

Volume

\( \hat{Z} \)

Z-axis unit vector

Greek symbols

θ

Polar angle in spherical coordinates

ω

Azimuthal angle in spherical coordinates

ϕ

Volume fraction

Subscripts

p

Nanoparticle

lr

Nanolayer

f

Base liquid

Copyright information

© Springer Science+Business Media B.V. 2008