Non-equilibrium molecular dynamics simulations are used to determine the thermal conductivities of single wall carbon nanotubes. By fixing opposing ends of an armchair single wall carbon nanotube with a Nose-Hoover thermostat, the length dependence of thermal conductivities of single wall carbon nanotubes were studied in a vacuum. Specifically, single wall carbon nanotubes of 12.3 nm, 24.6 nm, and 36.9 nm lengths with varying fixed end temperatures were analyzed to determine thermal conductivities. In addition, the fixed end temperature lengths of single wall carbon nanotubes were varied to see convergence of the temperature profiles. (C) 2010 Elsevier Ltd. All rights reserved.