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ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

A MICRO-CONVECTION MODEL FOR THERMAL CONDUCTIVITY OF NANOFLUIDS

Get access (open in a dialog) DOI: 10.1615/IHTC13.p8.240
12 pages

Abstract

The anomalously high thermal conductivity of nanofluids has been a matter of interest in recent times. There are many unresolved issues like the unusual dependence of thermal conductivity of nanofluids on particle concentration, particle size and temperature. Classical models for thermal conductivity of slurries fail to address any of them in nanofluids. The recently developed models also fail to address all of them. The present work gives a predictive model for thermal conductivity of nanofluids. The increase in thermal conductivity with reduction in particle size is attributed to the high surface area to volume ratio of nanoparticles as well as the micro-convection due to particle movement. The increase in the thermal conductivity with rise in temperature is justified by intensified Brownian motion of the particles, which causes additional convective effects. The present work uses a semi-empirical approach for the same by emphasizing above two effects through micro-convection. A new way of modeling thermal conductivity of nanofluids has been explored and found to agree excellently over a wide range of experimental data for various combinations of particles and fluids.