Numerical analysis of percolation formation in carbon nanotube based nanofluids

Abstract

SUMMARYThe intriguing behaviour of carbon nanotube suspensions shows that thermal conduction cannot be described by conventional approaches. These results led the researchers on the percolation and the interfacial layer resistance (also known as Kapitza resistance) as the main mechanisms governing the effective thermal conductivity enhancement for these nanoparticles suspensions. A numerical simulation on the behaviour of these suspensions, when subjected to a Brownian force field, was conducted to characterize the main factors affecting the dynamic interactions and percolation structures formation. To this end, three different numerical models based on continuum mechanics were developed. The obtained results suggest that the size, shape and aspect ratio of the nanoparticles are main factors controlling the dynamic network formation. On the other hand, the influence of the Brownian motion and the structural flexibility of the nanotubes seem to have a rather negligible effect on the results. The numerical model developed and proposed here may assist in understanding and correlating the experimental thermal conductivity data of nanofluids, contributing to demystify some of the intriguing behaviours reported. Copyright © 2013 John Wiley & Sons, Ltd.