Demixing phase transition in a mixture of hard-sphere dipoles and neutral hard spheres

1991 ◽  
Vol 67 (19) ◽  
pp. 2674-2677 ◽  
Author(s):  
X. S. Chen ◽  
M. Kasch ◽  
F. Forstmann
Keyword(s):  
Phase Transition ◽  
Hard Sphere ◽  
Hard Spheres

On the Concentration Fluctuations of a Binary Mixture of Hard Spheres

1988 ◽  
Vol 43 (10) ◽  
pp. 847-850 ◽  
Author(s):  
L. J. Gallego ◽  
J. A. Somoza ◽  
M. C. Blanco
Keyword(s):  
Phase Transition ◽  
Binary Mixture ◽  
Hard Sphere ◽  
Equations Of State ◽  
Hard Spheres ◽  
Fluid Phase ◽  
Packing Fraction ◽  
Concentration Fluctuations ◽  
Entropy Of Mixing ◽  
First Approximation

Abstract We have computed the concentration fluctuations, Scc(0), in a binary mixture of hard spheres on the basis of the Percus-Yevick compressibility (PYC), Percus-Yevick virial (PYV) and Mansoori- Carnahan-Starling (MCS) equations of state. We have also used the Flory-Huggins (FH) model for an athermal solution as a first approximation to the hard sphere description. At fluid packing fraction values, the PYC and MCS theories give similar Scc (0) results, whereas the differences between these and those derived from the PYV equation are more significant. The FH model appears to give rather bad results, which is consistent with the studies of other authors on the entropy of mixing of a binary mixture of hard spheres. The impossibility of a fluid-fluid phase transition in this kind of system is clearly shown by the behaviour of Scc (0) in any of the theories studied.

Critical consolute point in hard-sphere binary mixtures: Effect of the value of the eighth and higher virial coefficients on its location

2010 ◽  
Vol 75 (3) ◽  
pp. 359-369 ◽  
Author(s):  
Mariano López De Haro ◽  
Anatol Malijevský ◽  
Stanislav Labík
Keyword(s):  
Equation Of State ◽  
Binary Mixtures ◽  
Hard Sphere ◽  
Hard Spheres ◽  
Virial Coefficients ◽  
Fluid Mixture ◽  
Binary Fluid ◽  
Virial Series ◽  
Consolute Point ◽  
Critical Constants

Various truncations for the virial series of a binary fluid mixture of additive hard spheres are used to analyze the location of the critical consolute point of this system for different size asymmetries. The effect of uncertainties in the values of the eighth virial coefficients on the resulting critical constants is assessed. It is also shown that a replacement of the exact virial coefficients in lieu of the corresponding coefficients in the virial expansion of the analytical Boublík–Mansoori–Carnahan–Starling–Leland equation of state, which still leads to an analytical equation of state, may lead to a critical consolute point in the system.

scholarly journals Event-Driven Molecular Dynamics Simulation of Hard-Sphere Gas Flows in Microchannels

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Volkan Ramazan Akkaya ◽  
Ilyas Kandemir
Keyword(s):  
Molecular Dynamics ◽  
Hard Sphere ◽  
Stokes Equations ◽  
Hard Spheres ◽  
Flow Characteristics ◽  
Dynamics Simulation ◽  
Navier Stokes ◽  
Gas Flows ◽  
Linearized Boltzmann Equation ◽  
Event Driven

Classical solution of Navier-Stokes equations with nonslip boundary condition leads to inaccurate predictions of flow characteristics of rarefied gases confined in micro/nanochannels. Therefore, molecular interaction based simulations are often used to properly express velocity and temperature slips at high Knudsen numbers (Kn) seen at dilute gases or narrow channels. In this study, an event-driven molecular dynamics (EDMD) simulation is proposed to estimate properties of hard-sphere gas flows. Considering molecules as hard-spheres, trajectories of the molecules, collision partners, corresponding interaction times, and postcollision velocities are computed deterministically using discrete interaction potentials. On the other hand, boundary interactions are handled stochastically. Added to that, in order to create a pressure gradient along the channel, an implicit treatment for flow boundaries is adapted for EDMD simulations. Shear-Driven (Couette) and Pressure-Driven flows for various channel configurations are simulated to demonstrate the validity of suggested treatment. Results agree well with DSMC method and solution of linearized Boltzmann equation. At low Kn, EDMD produces similar velocity profiles with Navier-Stokes (N-S) equations and slip boundary conditions, but as Kn increases, N-S slip models overestimate slip velocities.

Solid-fluid phase transition of quantum hard spheres at finite temperatures

1988 ◽  
Vol 38 (1) ◽  
pp. 135-162 ◽  
Author(s):  
Karl J. Runge ◽  
Geoffrey V. Chester
Keyword(s):  
Phase Transition ◽  
Hard Spheres ◽  
Fluid Phase

New bounds on the sedimentation velocity for hard, charged and adhesive hard-sphere colloids

2011 ◽  
Vol 667 ◽  
pp. 403-425 ◽  
Author(s):  
W. TODD GILLELAND ◽  
SALVATORE TORQUATO ◽  
WILLIAM B. RUSSEL
Keyword(s):  
Brownian Motion ◽  
Upper Bound ◽  
Hard Sphere ◽  
Large Scale ◽  
Hard Spheres ◽  
Colloidal Dispersions ◽  
Sedimentation Velocity ◽  
Close Packing ◽  
Interparticle Potential ◽  
Equilibrium Microstructure

The sedimentation velocity of colloidal dispersions is known from experiment and theory at dilute concentrations to be quite sensitive to the interparticle potential with attractions/repulsions increasing/decreasing the rate significantly at intermediate volume fractions. Since the differences necessarily disappear at close packing, this implies a substantial maximum in the rate for attractions. This paper describes the derivation of a robust upper bound on the velocity that reflects these trends quantitatively and motivates wider application of a simple theory formulated for hard spheres. The treatment pertains to sedimentation velocities slow enough that Brownian motion sustains an equilibrium microstructure without large-scale inhomogeneities in density.

The nematic-isotropic phase transition in semiflexible fused hard-sphere chain fluids

2001 ◽  
Vol 114 (7) ◽  
pp. 3314-3324 ◽  
Author(s):  
K. M. Jaffer ◽  
S. B. Opps ◽  
D. E. Sullivan ◽  
B. G. Nickel ◽  
L. Mederos
Keyword(s):  
Phase Transition ◽  
Hard Sphere ◽  
Isotropic Phase ◽  
Chain Fluids

Molecular dynamics of hard sphere. III. Hard spheres in an almost spherical container

1988 ◽  
Vol 88 (7) ◽  
pp. 4448-4450 ◽  
Author(s):  
Y. P. Carignan ◽  
T. Vladimiroff ◽  
A. K. Macpherson
Keyword(s):  
Molecular Dynamics ◽  
Hard Sphere ◽  
Hard Spheres ◽  
Spherical Container

Semi-empirical insertion probability for hard-spheres and hard-sphere chains

2010 ◽  
Vol 299 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Ju Ho Lee ◽  
Jong Sung Lim ◽  
Hwayong Kim ◽  
Ki-Pung Yoo
Keyword(s):  
Hard Sphere ◽  
Hard Spheres ◽  
Semi Empirical
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