Development of a molecular-dynamics-based cluster-heat-capacity model for study of homogeneous condensation in supersonic water-vapor expansions

2013 ◽  
Vol 138 (6) ◽  
pp. 064302 ◽  
Author(s):  
Arnaud Borner ◽  
Zheng Li ◽  
Deborah A. Levin
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Water Vapor ◽  
Homogeneous Condensation ◽  
Capacity Model

Multicanonical Molecular Dynamics Simulation Study of the Liquid-Solid and Solid-Solid Transitions in Lennard-Jones Clusters

2011 ◽  
Author(s):  
Toshihiro Kaneko ◽  
Kenji Yasuoka ◽  
Ayori Mitsutake ◽  
Xiao Cheng Zeng
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Transition Temperature ◽  
Peak Position ◽  
Temperature Curve ◽  
Dynamics Simulation ◽  
Lennard Jones ◽  
Dynamics Simulations ◽  
First Time ◽  
Good Agreement

Multicanonical molecular dynamics simulations are applied, for the first time, to study the liquid-solid and solid-solid transitions in Lennard-Jones (LJ) clusters. The transition temperatures are estimated based on the peak position in the heat capacity versus temperature curve. For LJ31, LJ58 and LJ98, our results on the solid-solid transition temperature are in good agreement with previous ones. For LJ309, the predicted liquid-solid transition temperature is also in agreement with previous result.

scholarly journals The Impact of the Electric Field on Surface Condensation of Water Vapor: Insight from Molecular Dynamics Simulation

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 64 ◽  
Author(s):  
Qin Wang ◽  
Hui Xie ◽  
Zhiming Hu ◽  
Chao Liu
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Electric Field ◽  
Intermolecular Forces ◽  
Dynamics Simulation ◽  
Water Molecules ◽  
Attraction Force ◽  
Condensation Rate ◽  
Shape Transformation ◽  
The Impact

In this study, molecular dynamics simulations were carried out to study the coupling effect of electric field strength and surface wettability on the condensation process of water vapor. Our results show that an electric field can rotate water molecules upward and restrict condensation. Formed clusters are stretched to become columns above the threshold strength of the field, causing the condensation rate to drop quickly. The enhancement of surface attraction force boosts the rearrangement of water molecules adjacent to the surface and exaggerates the threshold value for shape transformation. In addition, the contact area between clusters and the surface increases with increasing amounts of surface attraction force, which raises the condensation efficiency. Thus, the condensation rate of water vapor on a surface under an electric field is determined by competition between intermolecular forces from the electric field and the surface.

Water vapor condensation on binary mixed substrates: A molecular dynamics study

2021 ◽  
pp. 122281
Author(s):  
Zi-Jie Wang ◽  
Shao-Yu Wang ◽  
Dan-Qi Wang ◽  
Yan-Ru Yang ◽  
Xiao-Dong Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Vapor Condensation ◽  
Mixed Substrates ◽  
Water Vapor Condensation

Melting at Mg/Al interface in Mg-Al-Mg nanolayer by molecular dynamics simulations

2021 ◽  
Author(s):  
Xue-Qi Lv ◽  
Xiong-Ying Li
Keyword(s):  
Molecular Dynamics ◽  
Heat Capacity ◽  
Distribution Function ◽  
Potential Energy ◽  
Density Distribution ◽  
Molecular Dynamics Simulations ◽  
Regional Research ◽  
Melting Temperatures ◽  
Essential Step ◽  
Dynamics Simulations

Abstract The melting at the magnesium/aluminum (Mg/Al) interface is an essential step during the fabrications of Mg-Al structural materials and biomaterials. We carried out molecular dynamics simulations on the melting at the Mg/Al interface in a Mg-Al-Mg nanolayer via analyzing the changes of average atomic potential energy, Lindemann index, heat capacity, atomic density distribution and radial distribution function with temperature. The melting temperatures (T m) of the nanolayer and the slabs near the interface are significantly sensitive to the heating rate (v h) over the range of v h≤4.0 K/ps. The distance (d) range in which the interface affects the melting of the slabs is predicted to be (-98.2, 89.9) Å at v h→0, if the interface is put at d=0 and Mg (Al) is located at the left (right) side of the interface. The (T m) of the Mg (Al) slab just near the interface (e.g., d=4.0 Å) is predicted to be 926.8 K (926.6 K) at v h→0, with 36.9 K (37.1 K) below 963.7 K for the nanolayer. These results highlight the importance of regional research on the melting at an interface in the nanolayers consisting of two different metals.

Explosive Boiling of Water on a Hot Copper Plate: A Molecular Dynamics Simulation Study

2020 ◽  
Vol 35 ◽  
pp. 18-28
Author(s):  
Muhammad Rubayat Bin Shahadat ◽  
A.K.M.M. Morshed
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Liquid Water ◽  
Hydrophobic Surface ◽  
Copper Plate ◽  
Dynamics Simulation ◽  
Hydrophilic Surface ◽  
Explosive Boiling ◽  
Different Temperatures ◽  
Simulation Results

Non-equilibrium molecular dynamics simulations have been employed to study the explosive boiling phenomena of water over a hot copper plate. The molecular system was comprised of three sections: solid copper wall, liquid water, and water vapor. A few layers of the liquid water were placed on the solid Cu surface. The rest of the simulation box was filled with water vapor. Initially, the water molecules were equilibrated by using Berendsen thermostat at 298 K. Then heat was given to the copper plate at different temperatures so that explosive boiling occurs. After achieving the equilibrium by performing the previous two steps, the liquid water at 298 K is suddenly dropped on the hot plate. NVE ensemble was used in the simulation and the temperature of the copper plate was controlled to different temperatures with phantom atom thermostat. Four temperatures (400K, 500K, 650 K and 1000K) were taken to study the explosive boiling. The simulation results show that, the explosive boiling temperature of water on Cu plate is 500 K temperature. At this point, the energy flux was found 1.79x108 J/m3 which is very promising with the experimental results. Moreover, if the temperature of the surface was increased the explosive boiling occurred at a faster rate. The simulation results also show that explosive boiling occurs earlier for the hydrophilic surface than hydrophobic surface as for the hydrophilic surface the water attracted the Cu plate more than the hydrophobic surface and so the amount of energy transfer is more for the hydrophilic surface.

Formation and migration of H3O+ and OH− ions at the water/silica and water/vapor interfaces under the influence of a static electric field: a molecular dynamics study

2020 ◽  
Vol 22 (39) ◽  
pp. 22537-22548
Author(s):  
Jesse Lentz ◽  
Stephen H. Garofalini
Keyword(s):  
Molecular Dynamics ◽  
Water Vapor ◽  
Electric Field ◽  
Glass Surface ◽  
Water Migration ◽  
Static Electric Field ◽  
Water Layers ◽  
And Migration

Water ‘layers’ 1 and 2 in pink; ‘layer’ 3 in blue and green over portion of glass surface (grey). +90° field causes water migration and clustering.

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