scholarly journals Effect of ambient gas pressure on characteristics of air plasma induced by nanosecond laser

2020 ◽  
Vol 69 (5) ◽  
pp. 057401
Author(s):  
Jia-He Liu ◽  
Jia-Zhe Lu ◽  
Jun-Jie Lei ◽  
Xun Gao ◽  
Jing-Quan Lin
Keyword(s):  
Gas Pressure ◽  
Nanosecond Laser ◽  
Air Plasma ◽  
Ambient Gas

Effect of ambient gas pressure on nanosecond laser produced plasma on nickel thin film in a forward ablation geometry

2018 ◽  
Vol 25 (10) ◽  
pp. 103108 ◽  
Author(s):  
Jinto Thomas ◽  
Hem Chandra Joshi ◽  
Ajai Kumar ◽  
Reji Philip
Keyword(s):  
Thin Film ◽  
Gas Pressure ◽  
Nanosecond Laser ◽  
Laser Produced Plasma ◽  
Ambient Gas

Effect of Argon Ambient Gas Pressure on Plume Expansion Dynamics

2011 ◽  
Vol 227 ◽  
pp. 129-133
Author(s):  
Farida Hamadi ◽  
El Hachemi Amara
Keyword(s):  
Transport Model ◽  
Gas Pressure ◽  
Nanosecond Laser Pulse ◽  
Nanosecond Laser ◽  
Expansion Velocity ◽  
Algebraic Equations ◽  
Plume Expansion ◽  
Degree Of Ionization ◽  
Vapor Plume ◽  
Ambient Gas

In this paper we present a numerical modeling of a nanosecond laser pulse interaction with a titanium target. We investigate the vapor plume formation and the influence of the ambient gas pressure on plume expansion dynamics. The vapor plume formation depends on the results of the heat transfer in the solid target modeling. The solid-liquid phase change is modeled by a two dimensional approach using an enthalpy formulation. The resulting plume expansion in the argon background gas is studied using the species transport model. The algebraic equations are discretized by the finite volume method implemented by Fluent CFD software [1]. The calculation results of plume expansion velocity, density, temperature and degree of ionization in the plume are presented.

Deposition of particulate-free thin films by two synchronised laser sources: effects of ambient gas pressure and laser fluence

2004 ◽  
Vol 446 (2) ◽  
pp. 178-183 ◽  
Author(s):  
E. György ◽  
I.N. Mihailescu ◽  
M. Kompitsas ◽  
A. Giannoudakos
Keyword(s):  
Thin Films ◽  
Laser Fluence ◽  
Gas Pressure ◽  
Laser Sources ◽  
Ambient Gas

Experimental and theoretical study of the characteristics of LSPR peaks for metal NPs produced by controlling Ar ambient gas pressure to enhance the efficiency of solar cells

2021 ◽  
pp. 1-6
Author(s):  
Serap Yiğit Gezgin ◽  
Abdullah Kepceoğlu ◽  
Hamdi Şükür Kiliç
Keyword(s):  
Metal Nanoparticles ◽  
Ag Nanoparticles ◽  
Solar Spectrum ◽  
Wavelength Region ◽  
Gas Pressure ◽  
Metal Nanoparticle ◽  
Ag Nanoparticle ◽  
Extinction Cross Section ◽  
Ambient Gas ◽  
Ar Gas

In this study, silver (Ag) nanoparticle thin films were deposited on microscope slide glass and Si wafer substrates using the pulsed-laser deposition (PLD) technique in Ar ambient gas pressures of 1 × 10−3 and 7.5 × 10−1 mbar. AFM analysis has shown that the number of Ag nanoparticles reaching the substrate decreased with increasing Ar gas pressure. As a result of Ar ambient gas being allowed into the vacuum chamber, it was observed that the size and height of Ag nanoparticles decreased and the interparticle distances decreased. According to the absorption spectra taken by a UV–vis spectrometer, the wavelength where the localised surface plasmon resonance (LSPR) peak appeared was shifted towards the longer wavelength region in the solar spectrum as Ar background gas pressure was decreased. This experiment shows that LSPR wavelength can be tuned by adjusting the size of metal nanoparticles, which can be controlled by changing Ar gas pressure. The obtained extinction cross section spectra for Ag nanoparticle thin film was theoretically analysed and determined by using the metal nanoparticle–boundary element method (MNPBEM) toolbox simulation program. In this study, experimental spectrum and simulation data for metal nanoparticles were acquired, compared, and determined to be in agreement.

Numerical Investigation on the Effect of Advanced Breakup Model on Spray Simulation of a Multi-Hole Injector

2018 ◽  
Author(s):  
Srinibas Tripathy ◽  
Sridhar Sahoo ◽  
Dhananjay Kumar Srivastava
Keyword(s):  
Mass Fraction ◽  
Gas Pressure ◽  
Gas Jet ◽  
Computational Time ◽  
Fuel Vapor ◽  
Computational Domain ◽  
Penetration Length ◽  
Spray Penetration ◽  
Ambient Gas ◽  
Vapor Mass

Computational fluid dynamics (CFD) plays a tremendous role in evaluating and visualizing the spray breakup, atomization and vaporization process. In this study, ANSYS Forte CFD tool was used to simulate the spray penetration length and spray morphology in a constant volume chamber at different grid size of a multi-hole injector. An unsteady gas jet model was coupled with Kelvin-Helmholtz (KH) and Rayleigh-Taylor (RT) model for multi-hole spray simulation. The effect of CFD cell size and ambient gas pressure on spray penetration length and spray morphology of fuel vapor mass fraction were investigated for both KH-RT and KH-RT with the unsteady gas jet model. It is found that KH-RT with the unsteady gas jet model shows mesh independent spray penetration length and spray morphology of fuel vapor mass fraction as compared to KH-RT model. This can be explained by the Lagrangian-Eulerian coupling of axial droplet-gas relative velocity is modeled on the principle of unsteady gas jet theory instead of discretizing very fine grid to the computational domain. This reduces the requirement of fine mesh near the nozzle and allows larger time step during spray injection. It is also observed that at higher ambient gas pressure, an aerodynamic force between the droplet and gas intensifies which reduces the overall spray penetration length and fuel vapor mass. The distorted spray morphology of fuel vapor mass fraction was accurately predicted at high ambient gas pressure using the KH-RT with an unsteady gas jet model which results in mesh independent drag predictions. The use of advanced spray model results in the mesh size dependency reduction and accurate drag prediction with less computational time and faster accurate solutions over all conventional spray breakup models.

The concentration and pressure dependent diffusion of carbon dioxide in nitrile rubbers

1992 ◽  
Vol 339 (1655) ◽  
pp. 497-519 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Diffusion Coefficient ◽  
High Pressures ◽  
Ambient Pressure ◽  
Weight Fraction ◽  
Gas Pressure ◽  
Time Dependent ◽  
Initial Increase ◽  
Parametric Function ◽  
Ambient Gas

The paper reports the results of an experimental and associated analytical study of the time dependent adsorption of carbon dioxide gas into two nitrile elastomers. The mass gas sorption has been measured using a device based on a vibrating reed to a weight fraction accuracy of ca . 0.05 % at 47 °C in the ambient gas pressure range 0.1-34 MPa. The experimental method is described and data are provided. These data are used to compute the most effective description of the diffusion process by invoking a number of different diffusion coefficient, D(θ), characteristics, where θ denotes lapsed time, ambient pressure and local ambient gas concentration within the elastomers. The numerical procedures adopted to perform the fitting of the experimental data with various D(θ) characteristics are described and the quality of the fit is assessed. The D(θ) characteristics chosen have no particular physical basis but follow established empirical precedents. The characteristics of the parameters associated with the various D(θ) functions generally indicate that as the gas is embibed with progressively increasing ambient pressures the diffusion coefficient increases. At high pressures the diffusion is arrested and the coefficient decreases. We have associated the initial increase with gas induced plasticization and the eventual decreases with the effect of the hydrostatic component of the ambient gas pressure. The parameter fitting also indicates that the diffusion is arrested with lapsed time which is tentatively associated with time dependent volumetric relaxations. These interpretations apart, the data and analyses clearly indicate that the transport is not simply fickian and a relatively complex parametric function to describe the sensitivity of the diffusion coefficient to time, concentration and pressure is necessary for these systems.

Thermal Conductivity of ZIF-8 Thin-Film under Ambient Gas Pressure

2017 ◽  
Vol 9 (34) ◽  
pp. 28139-28143 ◽  
Author(s):  
Boya Cui ◽  
Cornelius O. Audu ◽  
Yijun Liao ◽  
SonBinh T. Nguyen ◽  
Omar K. Farha ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Conductivity ◽  
Gas Pressure ◽  
Ambient Gas

scholarly journals Influence of ambient gas pressure on laser induced metal ablation

2010 ◽  
Vol 5 ◽  
pp. 255-259
Author(s):  
Yu. Chivel ◽  
V. Nasonov
Keyword(s):  
Gas Pressure ◽  
Ambient Gas
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