Molecular Dynamics Simulation of Heat Transfer and Phase Change During Laser Material Interaction

2001 ◽  
Vol 124 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Xinwei Wang ◽  
Xianfan Xu
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Phase Change ◽  
Pulsed Laser ◽  
Liquid Structure ◽  
Dynamics Simulation ◽  
Dynamics Simulations ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Material Interaction

In this work, heat transfer and phase change of an argon crystal irradiated by a picosecond pulsed laser are investigated using molecular dynamics simulations. The result reveals no clear interface when phase change occurs, but a transition region where the crystal structure and the liquid structure co-exist. Superheating is observed during the melting and vaporizing processes. The solid-liquid interface is found to move with a velocity of hundreds of meters per second, and the vapor is ejected from the surface with a vapor front velocity of hundreds of meters per second.

Molecular Dynamics Simulations of Interfacial Heat and Mass Transfer at Nanostructured Surface

2007 ◽  
Author(s):  
Gyoko Nagayama ◽  
Masako Kawagoe ◽  
Takaharu Tsuruta
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Boundary Condition ◽  
Thermal Resistance ◽  
Hydrodynamic Resistance ◽  
Hydrophilic Surface ◽  
Dynamics Simulations ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
The Continuum

The nanoscale heat and mass transport phenomena play important roles on the applications of nanotechnologies with great attention to its differences from the continuum mechanics. In this paper, the breakdown of the continuum assumption for nanoscale flows has been verified based on the molecular dynamics simulations and the heat transfer mechanism at the nanostructured solid-liquid interface in the nanochannels is studied from the microscopic point of view. Simple Lennard-Jones (LJ) fluids are simulated for thermal energy transfer in a nanochannel using nonequilibrium molecular dynamics techniques. Multi-layers of platinum atoms are utilized to simulate the solid walls with arranged nanostructures and argon atoms are employed as the LJ fluid. The results show that the interface structure (i.e. the solid-like structure formed by the adsorption layers of liquid molecules) between solid and liquid are affected by the nanostructures. It is found that the hydrodynamic resistance and thermal resistance dependents on the surface wettability and for the nanoscale heat and fluid flows, the interface resistance cannot be neglected but can be reduced by the nanostructures. For the hydrodynamic boundary condition at the solid-liquid interface, the no-slip boundary condition holds good at the super-hydrophilic surface with large hydrodynamic resistance. However, apparent slip is observed at the low hydrodynamic resistance surface when the driving force overcomes the interfacial resistance. For the thermal boundary condition, it is found that the thermal resistance at the interface depends on the interface wettability and the hydrophilic surface has lower thermal resistance than that of the hydrophobic surfaces. The interface thermal resistance decreases at the nanostructed surface and significant heat transfer enhancement has been achieved at the hydrophilic nanostructured surfaces. Although the surface with nanostrutures has larger surface area than the flat surface, the rate of heat flux increase caused by the nanostructures is remarkable.

Non-Equilibrium Molecular Dynamics Simulation of the Rapid Solidification of Metals

1989 ◽  
Vol 159 ◽  
Author(s):  
Cliff F. Richardson ◽  
Paulette Clancy
Keyword(s):  
Molecular Dynamics ◽  
Picosecond Laser ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Embedded Atom Method ◽  
Embedded Atom ◽  
Non Equilibrium Molecular Dynamics ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Non Equilibrium

ABSTRACTThe ultra-rapid melting and subsequent resolidification of Embedded Atom Method models of the fcc metals copper and gold are followed using a Non-Equilibrium Molecular Dynamics computer simulation method. Results for the resolidification of an exposed (100) face of copper at room temperature are in good agreement with recent experiments using a picosecond laser. At T = 0.5 Tm, the morphology of the solid/liquid interface is shown to be similar to a Lennard-Jones model. The morphology of the crystal-vapor interface at 92% of Tm shows a significant disordering of the topmost layers. Difficulties with the EAM model for gold are observed. Comparison of the Baskes et al. and Oh and Johnson embedding functions are discussed.

scholarly journals Molecular dynamics simulation of the solid-liquid interface migration in terbium

2018 ◽  
Vol 148 (21) ◽  
pp. 214705 ◽  
Author(s):  
M. I. Mendelev ◽  
F. Zhang ◽  
H. Song ◽  
Y. Sun ◽  
C. Z. Wang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Liquid Interface ◽  
Dynamics Simulation ◽  
Interface Migration ◽  
Solid Liquid Interface ◽  
Solid Liquid

Phase Change Heat Transfer During Melting and Resolidification of Melt Around Cylindrical Heat Source(s)/Sink(s)

1989 ◽  
Vol 111 (1) ◽  
pp. 43-49 ◽  
Author(s):  
K. Sasaguchi ◽  
R. Viskanta
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Phase Change Material ◽  
Liquid Interface ◽  
Cylinder Surface ◽  
Storage Unit ◽  
Energy Storage Unit ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Change Material

Melting and resolidification of a phase change material around two cylindrical heat exchangers spaced vertically have been investigated experimentally. Experiments have been performed to examine the effects of the cylinder surface temperatures on heat transfer during the melting and freezing cycle. The processes have been clarified on the basis of observations of timewise variations in the solid/liquid interface and of temperature distribution measurements in the phase change material. The results show that the solid/liquid interface contour during the melting and resolidification of the liquid from the upper cylinder is greatly affected by the surface temperature of the lower cylinder. The results show that multiple liquid regions may develop in the phase change material around the embedded heat sources/sinks, and the temperature swings and melting and freezing periods need to be selected properly in order to effectively utilize the phase change material in a latent heat energy storage unit.

Molecular Dynamics Simulations of Thermal Transport at the Nanoscale Solid-Liquid Interface

2013 ◽  
Vol 291-294 ◽  
pp. 1999-2003 ◽  
Author(s):  
Zhi Hai Kou ◽  
Min Li Bai ◽  
Guo Chang Zhao
Keyword(s):  
Molecular Dynamics ◽  
Thermal Resistance ◽  
Molecular Dynamics Simulations ◽  
Solid Wall ◽  
Liquid Interface ◽  
Heat Fluxes ◽  
Interfacial Thermal Resistance ◽  
Dynamics Simulations ◽  
Solid Liquid Interface ◽  
Solid Liquid

Simulation of nanoscale thermo-fluidic transport has attracted considerable attention in recent years owing to rapid advances in nanoscience and nanotechnology. The three- dimensional molecular dynamics simulations are performed for the system of a liquid layer between two parallel solid walls at different wall temperatures. The solid-solid interaction is modeled by the embedded atom method. The heat flux through the solid-liquid interface is calculated by Green-Kubo method. The effects of interface wettability and wall temperature on the interfacial thermal resistance are also analyzed. It is found that there exist the relatively immobile quasi-crystalline interfacial layers close to each solid wall surface with higher number density and thus higher local thermal conductivity than the corresponding liquid phase. The interfacial thermal resistance length is overestimated by 8.72% to 19.05% for the solid-solid interaction modeled by the Lennard-Jones potential, and underestimated based on heat fluxes calculated by Fourier equation.

Sign in / Sign up

Export Citation Format

Share Document