Eur. Phys. J. Special Topics 225, 1629-1642 (2016)
https://doi.org/10.1140/epjst/e2016-60137-4

Regular Article

On the establishment of thermal diffusion in binary Lennard-Jones liquids

¹ Dipartimento di Scienze Fisiche, Informatiche e Matematiche, University of Modena and Reggio Emilia, Via Campi 213/A, 41125 Modena, Italy
² CECAM Centre Européen de Calcul Atomique et Moléculaire, École Polytechnique Fédérale de Lausanne, Batochime, Avenue Forel 2, 1015 Lausanne, Switzerland
³ Institute for Applied Mathematics “Mauro Picone” (IAC), CNR, Via dei Taurini 19, 00185 Rome, Italy and University of Rome “La Sapienza”, P.le Aldo Moro 5, 00185 Rome, Italy and University College Dublin (UCD), Belfield, Dublin 4, Ireland

^a e-mail: mauro.ferrario@unimore.it
^b e-mail: sara.bonella@epfl.ch
^c e-mail: giovanni.ciccotti@roma1.infn.it

Received: 27 April 2016
Revised: 20 June 2016
Published online: 18 July 2016

Abstract

The establishment of thermal diffusion in an Ar-Kr Lennard-Jones mixture is investigated via dynamical non equilibrium molecular dynamics [G. Ciccotti, G. Jacucci, Phys. Rev. Lett. 35, 789 (1975)]. We observe, in particular, the evolution of the density and temperature fields of the system following the onset of the thermal gradient. In stationary conditions, we also compute the Soret coefficient of the mixture. This study confirms that dynamical non equilibrium molecular dynamics is an effective tool to gather information on transient phenomena, even though the full evolution of the mass and energy fluxes associated to the temperature and density fields requires, in this case, a more substantial numerical effort than the one employed here.