scholarly journals Mass Transfer through Vapour–liquid Interfaces: a Molecular Dynamics Simulation Study

2021 ◽  
Author(s):  
Simon Stephan ◽  
Dominik Schäfer ◽  
Kai Langenbach ◽  
Hans Hasse
Keyword(s):  
Molecular Dynamics ◽  
Mass Transfer ◽  
Molecular Dynamics Simulation ◽  
Mass Flux ◽  
Chemical Potential ◽  
Control Volume ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Liquid Interfaces ◽  
Simulation Volume

A quasi-stationary molecular dynamics simulation method for studying mass transfer through vapour–liquid interfaces of mixtures driven by gradients of the chemical potential based on the dual control volume (DCV) method is described and tested. The rectangular simulation volume contains three bulk domains: a liquid domain in the middle with vapour on each side such that there are two vapour–liquid interfaces. The mass flux is generated by prescribing the chemical potential in control volumes in the vapour domains close to the outer boundary of the simulation volume. The simulation method was applied for studies of two binary Lennard-Jones mixtures: one in which a strong enrichment of the low-boiling component at the vapour–liquid interface is observed and another in which there is practically no enrichment. The two mixtures differ only in the dispersive interactions; their bulk diffusion coefficients are similar. Furthermore, the prescribed chemical potential difference was the same in all simulations. Nevertheless, important differences in the mass flux of the low-boiling component were observed for the two mixtures at all studied temperatures which might be related to the enrichment at the interfaces.

Femtosecond photoelectron spectroscopy of the I2− anion: A semiclassical molecular dynamics simulation method

1999 ◽  
Vol 110 (8) ◽  
pp. 3736-3747 ◽  
Author(s):  
Victor S. Batista ◽  
Martin T. Zanni ◽  
B. Jefferys Greenblatt ◽  
Daniel M. Neumark ◽  
William H. Miller
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Photoelectron Spectroscopy ◽  
Simulation Method ◽  
Dynamics Simulation

Gradient-Driven Diffusion Using Dual Control Volume Grand Canonical Molecular Dynamics (DCV-GCMD)

1995 ◽  
Vol 408 ◽  
Author(s):  
Frank Van Swol ◽  
Grant S. Heffelfinger
Keyword(s):  
Molecular Dynamics ◽  
Chemical Potential ◽  
Control Volume ◽  
Simulation Method ◽  
Steady State Mode ◽  
Transient Phenomena ◽  
Insertion And Deletion ◽  
Separate Control ◽  
Control Volumes ◽  
Grand Canonical

AbstractRecently we developed a new nonequilibrium molecular simulation method [1] that allows the direct study of interdiffusion in multicomponent mixtures. The method combines stochastic insertion and deletion moves characteristic of grand canonical (GC) simulations with molecular dynamics (MD) to control the chemical potential μi of a species i. Restricting the insertions and deletions to two separate control volumes (CV's) one can apply different μ's in distinct locations, and thus create chemical potential gradients. DCV-GCMD can be used to study transient phenomena such as the filling of micropores or used in steady-state mode to determine the diffusion coefficients in multicomponent fluid mixtures. We report on the effects of molecular interactions and demonstrate how in a sufficiently nonideal ternary mixture this can lead to up-hill or reverse diffusion. In addition we introduce a novel extension of DCV-GCMD that is specifically designed for the study of gradient-driven diffusion of molecules that are simply too large to be inserted and deleted.

Multiscale flow characteristics of droplet spreading with microgravity conditions

2019 ◽  
Vol 97 (8) ◽  
pp. 869-874
Author(s):  
Xue-Qing Chen ◽  
Lei Tong
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Solid Wall ◽  
Gold Surface ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Contact Radius ◽  
Droplet Spreading ◽  
Fast Spreading ◽  
Slow Spreading

In this paper, mesoscopic lattice–Boltzmann method (LBM) and microscopic molecular dynamics simulation method were used to simulate droplet dynamic wetting under microgravity. In terms of LBM, the wetting process of a droplet on a solid wall surface was simulated by introducing the fluid–fluid and solid–fluid interactions. In terms of molecular dynamics simulation, the spreading process of water on gold surface was simulated. Calculation results showed that two kinds of calculation methods were based on the microscopic molecular theory or mesoscopic kinetics theory, and such models could effectively overcome the contact line paradox issue, which results from the macro-continuum assumption and non-slip boundary condition assumption. The spreading exhibits two-stage behavior: fast spreading and slow spreading stages. For the two simulation methods, the ratio of fast spreading stage duration to slow spreading duration, spreading capacity (equilibrium contact radius/initial radius), and the spreading exponent of the rapid stage were very close. However, the predictive spreading index of the slow spreading stage was different, owing to the different spreading mechanisms between meso- and nanoscales.

Estimation of the Chemical Potential and the Activity of NaCl in Molten DyCl3-NaCl by Molecular Dynamics Simulation

1998 ◽  
Vol 53 (8) ◽  
pp. 655-658
Author(s):  
Masanori Sakurai ◽  
Ryuzo Takagi ◽  
Ashok K. Adyaa ◽  
Marcelle Gaune-Escard
Keyword(s):  
Molecular Dynamics ◽  
Phase Diagram ◽  
Molecular Dynamics Simulation ◽  
Molecular Dynamics Simulations ◽  
Chemical Potential ◽  
Dynamics Simulation ◽  
Dynamics Simulations ◽  
Positional Data ◽  
Liquidus Temperatures

Abstract Molecular dynamics simulations of molten DyCl3-NaCl were carried out at liquidus temperatures of the phase diagram. The chemical potential and the activity of NaCl was successfully estimated with the method proposed by Powles et al., which requires only positional data of the ions at the temperatures in question.

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