The difference in the thermal conductivity of nanofluids measured by different methods and its rationalization

A suspension of particles below 100 nm in size, usually termed as nanofluid, often shows a notable enhancement in thermal conductivity, when measured by the transient hot-wire method. In contrast, when the conductivity of the same nanofluid is measured by the laser flash method, the enhancement repo...

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Bibliographic Details
Main Authors: Aparna Zagabathuni, Sudipto Ghosh, Shyamal Kumar Pabi
Format: Article
Language:English
Published: Beilstein-Institut 2016-12-01
Series:Beilstein Journal of Nanotechnology
Subjects:
Online Access:https://doi.org/10.3762/bjnano.7.194
Description
Summary:A suspension of particles below 100 nm in size, usually termed as nanofluid, often shows a notable enhancement in thermal conductivity, when measured by the transient hot-wire method. In contrast, when the conductivity of the same nanofluid is measured by the laser flash method, the enhancement reported is about one order of magnitude lower. This difference has been quantitatively resolved for the first time on the basis of the collision-mediated heat transfer model for nanofluids proposed earlier by our research group. Based on the continuum simulation coupled with stochastic analysis, the present theoretical prediction agrees well with the experimental observations from different measuring methods reported in the literature, and fully accounts for the different results from the two measuring methods mentioned above. This analysis also gives an indication that the nanofluids are unlikely to be effective for heat transfer in microchannels.
ISSN:2190-4286