Simulation of transport around the coexistence region of a binary fluid

Abstract

We use Monte Carlo and molecular dynamics simulations to study phase behavior and transport properties in a symmetric binary fluid where particles interact via Lennard-Jones potential. Our results for the critical behavior of collective transport properties, with particular emphasis on bulk viscosity, is understood via appropriate application of finite-size scaling technique. It appears that the critical enhancements in these quantities are visible far above the critical point. This result is consistent with an earlier report from computer simulations where, however, the authors do not quantify the critical singularity.

Finite-size scaling study of dynamic critical phenomena in a vapor-liquid transition

“…On the other hand, the situation with respect to dynamics is relatively poor. Simulation studies, that helped achieving the objective for the static phenomena, gained momentum in the context of dynamic critical phenomena only recently [25][26][27][28][29][30][31][32][33][34][35][36][37][38]. Such a status is despite the fact that adequate information on the equilibrium transport phenomena is very much essential for the understanding of even nonequilibrium phenomena like the kinetics of phase transitions [9,39].…”

Finite-size scaling study of shear viscosity anomaly at liquid-liquid criticality

“…Interestingly, this is at variance with the critical range of bulk viscosity and Onsager coefficient for this particular model. [8][9][10][11] For these quantities, the expected power laws were observed up to even 100% above T c . In the inset of Fig.…”

“…We consider a binary fluid model [8][9][10][11] where particles, all of same mass m, at continuum positions r i and r j , interact via the Lennard-Jones (LJ) pair potential…”

“…1,3,4 Due to this reason, simulation studies of the dynamic critical phenomena are very recent. [5][6][7][8][9][10][11] In the vicinity of a critical point, various static and dynamic properties exhibit power-law singularities. 1,[12][13][14] For example, in static critical phenomena, the correlation length (ξ ), the order parameter (m), and the susceptibility (χ ) behave as 1,12 …”

“…For a liquid-liquid transition, singularities of D AB and ζ were recently verified via molecular dynamics (MD) simulations. [8][9][10][11] However, the quality of data was not high enough to draw a conclusion on the anomaly of η, because of the tiny value of x η . Via MD simulations, 4, 27, 28 fluid transport properties are traditionally calculated using microcanonical ensemble Before each of these runs, the system was appropriately equilibrated for long enough time via Monte Carlo runs in a canonical ensemble and further, thermalized via molecular dynamics runs with the Andersen thermostat.…”