Thermal rectification reversal in carbon nanotubes
Loh, G. C.
Teo, Edwin Hang Tong
Tay, Beng Kang
Date of Issue2012
School of Electrical and Electronic Engineering
In principle, rectifying phonon and electron flows appear similar, whereby more energy is transported in one direction than the opposite one. However, their physical mechanisms are inherently different. By using molecular dynamics simulations, this study reports on a few interesting aspects of thermal rectification in carbon nanotubes: (1) The dependence of the rectification ratio on the structural symmetry (represented by the position of vacancy clusters) of the nanotube and more importantly (2) a reversal in the rectifying direction as the normalized temperature difference of the heat baths is increased. The flux-mediated diffuse mismatch model is extended to explain the reversal phenomenon—initially with a simplifying assumption that the transmission coefficients at the vacancy/scatterer are identical in bidirectional phonon transport, and then with a moderating factor to distinguish between both coefficients. It is noted that in both cases, the conditions for thermal rectification reversal are attainable and thus explain the results of the simulations.
DRNTU::Engineering::Electrical and electronic engineering
Journal of applied physics
© 2012 American Institute of Physics. This paper was published in Journal of Applied Physics and is made available as an electronic reprint (preprint) with permission of American Institute of Physics. The paper can be found at the following official DOI: [http://dx.doi.org/10.1063/1.4766391]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.