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

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.

scholarly journals Backward clusters, hierarchy and wild sums for a hard sphere system in a low-density regime

2015 ◽  
Vol 25 (05) ◽  
pp. 995-1010 ◽  
Author(s):  
Kazuo Aoki ◽  
Mario Pulvirenti ◽  
Sergio Simonella ◽  
Tetsuro Tsuji
Keyword(s):  
Molecular Dynamics ◽  
Hard Sphere ◽  
Hard Spheres ◽  
Upper And Lower Bounds ◽  
Low Density ◽  
Time Dynamics ◽  
Homogeneous Boltzmann Equation ◽  
Dynamics Simulations ◽  
Average Size ◽  
Density Regime

We study the statistics of backward clusters in a gas of hard spheres at low density. A backward cluster is defined as the group of particles involved directly or indirectly in the backwards-in-time dynamics of a given tagged sphere. We derive upper and lower bounds on the average size of clusters by using the theory of the homogeneous Boltzmann equation combined with suitable hierarchical expansions. These representations are known in the easier context of Maxwellian molecules (Wild sums). We test our results with a numerical experiment based on molecular dynamics simulations.

Wetting of a Smooth Substrate by Crystal

1991 ◽  
Vol 237 ◽  
Author(s):  
David J. Courtemanche ◽  
Frank van Swol
Keyword(s):  
Molecular Dynamics ◽  
Hard Sphere ◽  
Hard Spheres ◽  
Phase System ◽  
Hard Wall ◽  
Direct Simulation ◽  
Two Phase ◽  
Complete Wetting ◽  
Hard Sphere Fluid ◽  
Partial Wetting

AbstractWe report on a molecular dynamics (MD) study of the wetting state of a system of hard spheres near a smooth planar hard wall. A direct simulation at the melting point of a two-phase system between two walls develops all the way from complete wetting by fluid (cos(θ) = 0) via partial wetting state to a final arrangement of complete wetting by crystal (cos(θ) = 1). This implies that a hard sphere fluid spontaneously crystallizes at a smooth hard wall, contrary to existing beliefs.

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.

Molecular dynamics of a hard sphere fluid in small pores

1979 ◽  
Vol 38 (4) ◽  
pp. 1061-1066 ◽  
Author(s):  
G. Subramanian ◽  
H.T. Davis
Keyword(s):  
Molecular Dynamics ◽  
Hard Sphere ◽  
Hard Sphere Fluid
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