Molecular Dynamics Simulation for Homogenous Nucleation of Water and Liquid Nitrogen in Explosive Boiling

2009 ◽  
Author(s):  
Yu Zou ◽  
Xiulan Huai
Keyword(s):  
Molecular Dynamics ◽  
Energy Conversion ◽  
Liquid Nitrogen ◽  
Laser Heating ◽  
Equilibrium Temperature ◽  
Dynamics Simulation ◽  
Working Fluid ◽  
Heating Zone ◽  
Explosive Boiling ◽  
Heat Quantity

Molecular dynamics simulations are carried out to study the energy conversion in the homogeneous nucleation processes of the explosive boiling caused by laser heating. Liquid nitrogen and water are investigated as the working fluid. Velocity scaling method is applied to realize the laser heating process. Three influencing factors, the heat quantity into the system, the area of the laser heating zone and the initial equilibrium temperature of the liquid are analyzed. It is found that the conversion ratio of energy between heat quantity and potential energy is from 66% to 78% in the process of laser heating. The influence of the heat quantity into the system on the energy conversion of liquid nitrogen is the same in trend as that of water. The influence of the initial equilibrium temperature and the area of the laser heating zone on the liquid nitrogen is less than that of water. The difference of energy conversion between water and liquid nitrogen is pretty dramatic, which is because of the hydrogen bond formed by the Coulombic interaction among water molecules.

Application of CO2 laser heating zone drawing and zone annealing to nylon 6 fibers

2001 ◽  
Vol 83 (8) ◽  
pp. 1711-1716 ◽  
Author(s):  
Akihiro Suzuki ◽  
Masayoshi Ishihara
Keyword(s):  
Co2 Laser ◽  
Laser Heating ◽  
Nylon 6 ◽  
Heating Zone

Features of laser drilling of porous aluminosilicate ceramics

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3045-3054
Author(s):  
P.A. Márquez Aguilar ◽  
M. Vlasova ◽  
E. Moreno Bernal ◽  
M. Kakazey ◽  
R. Guardian Tapia ◽  
...  
Keyword(s):  
Laser Heating ◽  
Glass Phase ◽  
Porous Ceramics ◽  
Heating Zone ◽  
Dynamic Impact ◽  
Laser Perforation ◽  
Temperature Heating ◽  
Thermo Physical Properties ◽  
Highly Porous ◽  
High Temperature Heating

AbstractStudies have shown that local laser heating/“drilling” of composite large-porous ceramics consisting of aluminosilicates and glass phase is based on melting and ablation processes that lead to the formation of holes in a porous specimen. The interaction of the components of the composite in the high-temperature heating zone is accompanied by the formation of glass-phase melt of new composition. The advance of the melt deep into the sample along channel-like pores of the main ceramic material depends on the viscosity of the melt (i.e., the irradiation mode) and the cooling rate of the melt (i.e., the thermo-physical properties of the ceramics and glass phase). The development of gas-dynamic impact in the laser heating zone leads not only to the ejection of a part of the melt from the channel, but also to the compaction of the ceramics adjacent to the walls of the vitrified channel. These effects depend heavily on the ceramic-to-glass phase ratio and the porosity of the initial ceramic. It has been established that “laser perforation” of highly porous aluminosilicate ceramics leads to the hardening of the coarse-porous ceramics due to the formation of holes with strong walls, consisting of layers of the glass phase and compacted ceramics in the sample.

Studying Powdery Admixture Supply to the Laser Heating Zone in 3D Metal Printing

2021 ◽  
Vol 50 (1) ◽  
pp. 41-45
Author(s):  
A. Yu. Albagachiev ◽  
N. N. Chunikhin ◽  
N. I. Minaeva
Keyword(s):  
Laser Heating ◽  
Heating Zone ◽  
Metal Printing ◽  
3D Metal Printing

Temperature distribution within and outside the laser heating zone

2015 ◽  
Author(s):  
Albert V. Korolev ◽  
Andrey A. Korolev ◽  
Michel M. Zhuravlev
Keyword(s):  
Temperature Distribution ◽  
Laser Heating ◽  
Heating Zone

High-resolution EM investigation about effect of stress on formation of ω-phase crystals in β-tttanium alloys

1996 ◽  
Vol 54 ◽  
pp. 1006-1007
Author(s):  
E. Sukedai ◽  
M. Shimoda ◽  
A. Fujita ◽  
H. Nishizawa ◽  
H. Hashimoto
Keyword(s):  
High Resolution ◽  
Titanium Alloys ◽  
High Resolution Electron Microscopy ◽  
Dark Field ◽  
Zone Refining ◽  
Ω Phase ◽  
Α Phase ◽  
Nucleation Sites ◽  
Resolution Electron ◽  
Bcc Structure

ω-phase particles formed in β-titanium alloys (bcc structure) act important roles to their mechanical properties such as ductility and hardness. About the ductility, fine ω-phase particles in β–titanium alloys improve the ductility, because ω-phase crystals becomes nucleation sites of α-phase and it is well known that (β+α) duplex alloys have higher ductility. In the present study, the formation sites and the formation mechanism of ω-phase crystals due to external stress and aging are investigated using the conventional and high resolution electron microscopy.A β-titanium alloy (Til5Mo5Zr) was supplied by Kobe Steel Co., and a single crystal was prepared by a zone refining method. Plates with {110} surface were cut from the crystal and were pressured hydrostatically, and stressed by rolling and tensile testing. Specimens for aging with tensile stress were also prepared from Ti20Mo polycrystals. TEM specimens from these specimens were prepared by a twin-jet electron-polishing machine. A JEM 4000EX electron microscope operated at 400k V was used for taking dark field and HREM images.

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