Molecular Dynamics Simulation of Heat-Conducting Near-Critical Fluids

Toshiyuki Hamanaka, Ryoichi Yamamoto, Akira Onuki

Published 2004-05-13, updated 2004-09-03Version 3

Using molecular dynamics simulations, we study supercritical fluids near the gas-liquid critical point under heat flow in two dimensions. We calculate the steady-state temperature and density profiles. The resultant thermal conductivity exhibits critical singularity in agreement with the mode-coupling theory in two dimensions. We also calculate distributions of the momentum and heat fluxes at fixed density. They indicate that liquid-like (entropy-poor) clusters move toward the warmer boundary and gas-like (entropy-rich) regions move toward the cooler boundary in a temperature gradient. This counterflow results in critical enhancement of the thermal conductivity.