271 research outputs found
Study of Critical Dynamics in Fluid via Molecular Dynamics in Canonical Ensemble
With the objective of demonstrating usefulness of thermostats in the study of
dynamic critical phenomena in fluids, we present results for transport
properties in a binary Lennard-Jones fluid that exhibits liquid-liquid phase
transition. Results from the molecular dynamics simulations in canonical
ensemble, with various thermostats, are compared with those from microcanonical
ensemble. It is observed that the Nos\'{e}-Hoover and dissipative particle
dynamics thermostats are useful for the calculations of mutual diffusivity and
shear viscosity. The Nos\'{e}-Hoover thermostat, however, appears inadequate
for the study of bulk viscosity.Comment: 5 pages, 4 figures in European Physical Journal E 201
Finite-size Scaling Study of Shear Viscosity Anomaly at Liquid-Liquid Criticality
We study equilibrium dynamics of a symmetrical binary Lennard-Jones fluid
mixture near its consolute criticality. Molecular dynamics simulation results
for shear viscosity, , from microcanonical ensemble are compared with
those from canonical ensemble with various thermostats. It is observed that
Nos\'{e}-Hoover thermostat is a good candidate for this purpose and so, is
adopted for the quantification of critical singularity of , to avoid
temperature fluctuation (or even drift) that is often encountered in
microcanonical simulations. Via finite-size scaling analysis of our simulation
data, thus obtained, we have been able to quantify even the weakest anomaly, of
all transport properties, that shear viscosity exhibits and confirm the
corresponding theoretical prediction.Comment: 6 pages, 6 figure
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