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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

THERMAL CONDUCTIVITY OF SINGLE WALL CARBON NANOTUBES: A COMPARISON OF MOLECULAR DYNAMICS SIMULATION APPROACHES

Get access (open in a dialog) DOI: 10.1615/IHTC13.p8.290
14 pages

Sinopsis

This paper examines the influence of molecular dynamics simulation approach on the calculated thermal conductivity of (10, 10) single-wall carbon nanotubes at 300 K. Equilibrium, direct nonequilibrium, and homogeneous nonequilibrium approaches are compared for a variety of nanotube lengths and boundary conditions. Increases in thermal conductivity with nanotube length occur in all approaches, and cumulative density of states calculations reveal enhancement of low-frequency modes in longer nanotubes. Differences in thermal conductivity magnitude are evident for the various simulation approaches. These differences are attributed to several factors: differences in average system stiffness arising from the different boundary conditions employed, linear versus quadratic dependence of thermal conductivity on heat current for homogeneous nonequilibrium and equilibrium approaches, and internal stress. Based on comparison of results from the various approaches, we propose a new method for eliminating size effects and estimating bulk conductivity from MD simulation, even for simulation domains much smaller than the bulk phonon mean free path. Macroscopic thermal conductivities estimated using this method are of the order 1000 − 3000 W/m·K, which are consistent with recent experimental measurements of carbon nanotube thermal conductivity.