Soret coefficient for liquid argon-krypton mixtures via equilibrium and nonequilibrium molecular dynamics: A comparison with experiments

Abstract

The Soret and the other transport coefficients, characterizing the heat and mass transport in binary mixtures, have been obtained by equilibrium and nonequilibrium molecular dynamics (EMD and NEMD, respectively). Two state points of the argon-krypton mixture are considered, for which experimental values of the Soret coefficient are available. To attempt a comparison between simulations and experiments the common enthalpy-diffusion-free expression for the heat flux has been chosen. The comparison of the simulations with the experiments shows a remarkable agreement, for all the several utilized EMD and NEMD techniques (dynamical and stationary). The techniques, used over 0.3 micros of total simulation time span, are slow convergent but have comparable performances.

Interfacial Excess Free Energies of Solid–Liquid Interfaces by Molecular Dynamics Simulation and Thermodynamic Integration

“…However, our goal here is to probe the methodology, thus, we decided to avoid long-range corrections to pressure by using a modified Lennard-Jones potential such that forces vanish at the cut-off. Thus, we used splined forces [12,32] such that the force acting between atoms is a Lennard-Jones force if the distance between the atoms is lower than the spline radius and has a cubic polynomial form in between the spline and the cut-off radii. We used a cut-off radius of 3.5 and a spline radius of 2.5.…”

Thermotransport in binary system: case study on Ni50Al50melt

“…Another route is based on equilibrium MD simulations [15][16][17]21,25,26]. Statistical mechanics is able to provide a general expression for the heat of transport in terms of an integral of the time correlation function between heat flux and matter flux evaluated for the system in thermodynamic equilibrium.…”

“…At the same time, theoretical modelling of thermotransport still lacks a clear and convincing fundamental understanding of the process at the atomistic level. Accordingly, computer simulation techniques such as molecular dynamics (MD) which operate at the atomistic level are useful for obtaining valuable insight into the thermotransport phenomenon [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26].…”

Experimental investigation of the Soret effect in acetone/water and dimethylsulfoxide/water mixtures

“…6,9,15,16 Molecular dynamics (MD) simulations have become an important tool in the investigation of thermal diffusion behavior of Lennard-Jones model fluids and small-molecule liquids. [17][18][19][20][21] Lately, the simulation techniques for non-equilibrium properties have been improved, which have led to a reasonable agreement between simulations and experiments for associating and non-associating liquid mixtures. [21][22][23] Simulations and also a two-chamber lattice model calculation have shown that the relation between the cross interactions and the pure interactions determine whether the sign of the Soret coefficient changes with concentration.…”