Wetting of a Smooth Substrate by Crystal

MRS Proceedings ◽

10.1557/proc-237-73 ◽

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.

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Molecular dynamics of a hard sphere fluid in small pores

Molecular Physics ◽

10.1080/00268977900102241 ◽

1979 ◽

Vol 38 (4) ◽

pp. 1061-1066 ◽

Cited By ~ 18

Author(s):

G. Subramanian ◽

H.T. Davis

Keyword(s):

Molecular Dynamics ◽

Hard Sphere ◽

Hard Sphere Fluid

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

Mathematical Problems in Engineering ◽

10.1155/2015/842837 ◽

2015 ◽

Vol 2015 ◽

pp. 1-12 ◽

Cited By ~ 8

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.

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