Imaging and Characterization of Plasma Plumes Produced During Laser Ablation of Zirconium Carbide

1992 ◽  
Vol 285 ◽  
Author(s):  
Darryl P. Butt ◽  
Paul J. Wantuck
Keyword(s):  
Zirconium Carbide ◽  
Ccd Camera ◽  
Laser Induced Fluorescence ◽  
Diagnostic Methods ◽  
Total Emission ◽  
Low Emission ◽  
Laser Diagnostic ◽  
Planar Laser ◽  
Plasma Plumes

ABSTRACTLaser diagnostic methods are developed and used to characterize the behavior of laser ablated zirconium carbide (ZrC). Emission from zirconium atoms dominates the total emission of the plasma plumes, which are estimated to have excitation temperatures of 9000 to 12,000 K under the conditions studied. Emission from species such as C, C2, and C3 were absent from the spectra due to the inherently low emission intensities of these species compared with that of Zr. Using a CCD camera, images of the plasma plumes are obtained from the emission and through the use of planar laser induced fluorescence of zirconium atoms.

Feasibility Studies and Application of Laser /Optical Diagnostics for Characterisation of a Practical Low-Emission Gas Turbine Combustor

2000 ◽  
Author(s):  
C. Löfström ◽  
J. Engström ◽  
M. Richter ◽  
C. F. Kaminski ◽  
P. Johansson ◽  
...  
Keyword(s):  
Feasibility Studies ◽  
Mie Scattering ◽  
Diagnostic Techniques ◽  
Laser Induced Fluorescence ◽  
Gas Turbine Combustor ◽  
Atomic Fluorescence ◽  
Two Photon ◽  
Low Emission ◽  
Laser Diagnostic ◽  
Planar Laser

The present paper presents applications and feasibility studies of a number of laserspectroscopic techniques in a lean premixed prevaporised (LPP) combustor. Four different laser diagnostic techniques were investigated. The two more mature techniques, Planar Mie Scattering/Laser Induced Fluorescence and Planar Laser Induced Fluorescence of OH were used for fuel- and OH-visualisation, respectively. In addition, the applicability of some novel techniques in harsh industrial environments were investigated, two-line atomic fluorescence (TLAF) to obtain 2-dimensional temperature distributions, and two-photon LIF for the detection of CO. In order to investigate the degree of turbulence an ultrafast framing camera was employed to record spontaneous emission.

Characterization of the COBRA triple-nozzle gas-puff valve using planar laser induced fluorescence

2014 ◽  
Author(s):  
P. W.L. de Grouchy ◽  
E. Rosenberg ◽  
N. Qi ◽  
B. R. Kusse ◽  
E. Kroupp ◽  
...  
Keyword(s):  
Laser Induced Fluorescence ◽  
Planar Laser Induced Fluorescence ◽  
Planar Laser

scholarly journals Statistical Analysis of Flame Oscillation Characterization of Oxy-Fuel in Heavy Oil Boiler Using OH Planar Laser-Induced Fluorescence

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Xin Yu ◽  
Zhen Cao ◽  
JiangBo Peng ◽  
Yang Yu ◽  
Guang Chang ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Heavy Oil ◽  
Laser Induced Fluorescence ◽  
Peak Position ◽  
Flame Surface ◽  
Flame Combustion ◽  
Planar Laser Induced Fluorescence ◽  
Planar Laser ◽  
Flame Oscillation

The present work investigated the flame structures and oscillations of oxy-fuel combustions in a heavy oil boiler using OH planar laser-induced fluorescence imaging. Combustion instabilities, such as flame oscillation and combustion fluctuation, can assess the performance of an industrial burner in the boiler. The peak position variation in OH concentration was associated with the change of the reaction zone that corresponded with the fluctuation of the heat-release zone in the combustion chamber, which provides a valuable reference for the design of the combustion chamber. The experimental results suggest that the phenomenon of stratified flame combustion is related to the characteristic of flame oscillation. The substitution of N2 with CO2 will not significantly influence the flame oscillation frequency but increases the number of flame surface. As O2 concentration increased in the O2/CO2 atmosphere, the phenomenon of stratified flame combustion disappeared, and the flame presented an island-like structure. The bimodal oscillation of the combustion center was demonstrated by means of the probability density method; CO2 played a role in the extension of the combustion center. The combustion fluctuation of inner regions was quantitatively described; CO2 could maintain interregional stabilization to some extent. Compared with traditional measurement methods, PLIF technology has great advantages in evaluating burner performance and optimizing the design of the combustion chamber.

Profiling of Redox Atmosphere in Flames by Chemical Seeding/Planar Laser-Induced Fluorescence (CS/PLIF)

2005 ◽  
Vol 128 (4) ◽  
pp. 765-772 ◽  
Author(s):  
K. Kitagawa ◽  
S. Itoh ◽  
N. Arai ◽  
Ashwani K. Gupta
Keyword(s):  
Rotational Temperature ◽  
Thermal Dissociation ◽  
Flame Temperature ◽  
Ccd Camera ◽  
Laser Induced Fluorescence ◽  
Charge Coupled Device ◽  
Planar Laser ◽  
A Charge ◽  
Local Value ◽  
Redox Index

Knowledge on the local value of reducing and oxidizing (redox) atmospheres in flames is among the most important issues to be desired by combustion engineers. In this study, the spatial distribution of a redox atmosphere in flames has been measured experimentally by the chemical seeding/laser-induced fluorescence (CS/LIF) technique. A solution of iron was sprayed into a premixed propane-air flame supported on a slot burner. The LIF intensity of FeO band was compared to that of a Fe line to estimate the experimentally determined degree of atomization in the reaction FeO→Fe+O. The flame temperature profile was determined as a rotational temperature and was obtained by comparing the LIF (laser-induced fluorescence) intensities of OH rotational lines. The degree of atomization was theoretically calculated on the basis that simple thermal dissociation takes place in the reaction. The redox atmosphere, or a redox index, is defined as the ratio of the experimentally determined to theoretically calculated degrees of atomization. Two-dimensional distributions or profiles of the excitation temperature, experimentally determined degree of atomization, and redox index have been measured using a charge coupled device (CCD) camera fitted with an optical bandpass filter and the associated signal processing using a computer. This method has been successfully applied to quantitatively illustrate the local atmosphere and profile of the redox atmosphere in flames.

In situ characterization of vapor phase growth of iron oxide-silica nanocomposites: Part I. 2-D planar laser-induced fluorescence and Mie imaging

1996 ◽  
Vol 11 (6) ◽  
pp. 1552-1561 ◽  
Author(s):  
Brian K. McMillin ◽  
Pratim Biswas ◽  
Michael R. Zachariah
Keyword(s):  
Iron Oxide ◽  
Vapor Phase ◽  
Particle Growth ◽  
Laser Induced Fluorescence ◽  
Vapor Concentration ◽  
In Situ Characterization ◽  
Silica Nanocomposites ◽  
Planar Laser

Planar laser-based imaging measurements of fluorescence and particle scattering have been obtained during flame synthesis of iron-oxide/silica superparamagnetic nanocomposites. The theory and application of laser-induced fluorescence, the spectroscopy of FeO(g), and the experimental approach for measurement of gas phase precursors to particle formation are discussed. The results show that the vapor phase FeO concentration rapidly rises at the primary reaction front of the flame and is very sensitive to the amount of precursor added, suggesting nucleation-controlled particle growth. The FeO vapor concentration in the main nucleation zone was found to be insensitive to the amount of silicon precursor injected, indicating that nucleation occurred independently for the iron and silicon components. Light scattering measurements indicate that nanocomposite particles sinter faster than single component silica, in agreement with TEM measurements.

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