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Showing 1 to 20 of 56 for “"diffusion flame"”.
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Development of a micro-FID using a diffusion flame
A micro-flame ionization detector (micro-FID) was developed operating with a diffusion flame with a folded flame structure. Unlike conventional FIDs, an air-hydrogen diffusion flame was developed and tested in an encapsulated structure of Quartz-Macor®-Quartz layers. Diffusion flames are generally …
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The stabilization and extinction of a microjet diffusion flame
The steady jet diffusion micro-flame is mathematically modeled and its extinction properties and investigated in this study. The diffusion flame of interest is one that results from the reaction of a fuel present in a weak jet issuing from a nozzle into an unbounded medium containing the oxidizer. …
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Spectroscopic measurement of nitric oxide in a diffusion flame
… measurements of NO and NO₂ produced by a diffusion flame around a cotton ball wetted by heptane have been performed and prove that NO is oxidized to NO₂ on a mole for mole basis when the air of the flame is doped with hydrogen and that the NO to NO₂ mechanism does not require carbon atoms …
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Velocity, temperature, and electric field measurements on a plasma-assisted hydrogen diffusion flame
A plasma-assisted hydrogen diffusion flame, denoted as a coaxial AC DBD burner, was designed and analyzed for comparisons with simulations and to better understand the coupling of the plasma and reacting flow. Emission, PLIF, and schlieren imaging of the burner revealed three distinct operating …
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Investigations of the Effects of Flame Configuration on the Combustion of Laminar Diffusion Flame
Motivation and objective to study double inverse diffusion flame is introduced, followed by the literature survey on soot formation in inverse diffusion flame (IDF), application of the unique structure of double inverse diffusion flame (DIDF), radiation effects on DIDF, factors that affect the …
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Experimental determination of the flow field velocity and strain rate in a laminar opposed flow H₂/air diffusion flame, via laser doppler anemometry
… investigation of an opposed flow hydrogen-air diffusion flame was conducted. The purpose was to experimentally determine the flow field velocity and corresponding strain rate under different operating flow conditions. An axisymmetric opposed jet burner was employed in this experiment where air …
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Soot formation in vitiated-air diffusion flames
… measured using optical techniques in dual mode diffusion flames. A dual mode flame is defined as a diffusion fuel jet that burns in the wake of a premixed flame. The premixed flame combustion products simulate a vitiated-air environment: the air is preheated, rich in radicals, and depleted in …
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A Study of Ion Concentration Fluctuations in Turbulent Diffusion Flames using Correlation Techniques
… equilibrium ion chemical kinetics in a turbulent diffusion flame. In such a system the charged species undergo a chemical reaction concurrently with turbulent mixing. Where the chemical reaction rate is greater than the appropriate mixing rate it has been theoretically predicted that a measurable …
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Effects of high levels of steam addition on NOx̳ reduction in laminar opposed flow diffusion flames
… has been observed in industrial gas turbine diffusion flame combustors. Experiments were performed to try to reproduce this trend in a laminar, opposed flow diffusion flame burner. Experiments were performed with Cli4, C2H4, CO, COIH2 (1:1), and COIH2 (1:2) as fuels. Both hydrocarbon fuels …
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Experimental and Numerical Studies on the Soot Formation of Liquid Fuel Relevant Compounds
… and aggregate structure in a laminar coflow diffusion flame using the combined laser extinction and two-angle elastic light scattering method. It is shown that the relative importance of soot inception and surface growth affected by n-propylbenzene addition is different along the flame wing …
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Combustion dynamics of metal powders in mixed gas flows
… environment consists of a laminar air-acetylene flame; auxiliary tangential jets of air with adjustable flow rates are used to achieve different controlled levels of turbulence. The second environment consists of a hydrogen/oxygen diffusion flame. In both cases, metal powder is injected in the …
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Development and experimental analysis of a micro-flame ionization detector for portable gas chromatographs
… micro-FID has been developed that utilized a diffusion flame encased in a micro-fabricated SOI structure. The micro-flame was fueled by a portable electrolyzer that provided the hydrogen and oxygen flow rates necessary for the device operation. The micro-FID was able to detect organic analytes …
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Effects Of Transport Properties And Flame Unsteadiness On Nitrogen Oxides Emissions From Laminar Hydrogen Jet Diffusion Flames
… on laminar, acoustically forced, hydrogen jet diffusion flames diluted by argon and helium. The primary purpose of this research is to determine how the fuel Lewis number and the flow unsteadiness play a combined role in maximum flame temperature and affect NOx emission from jet diffusion …
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Comprehensive Computational Modeling of Hypergolic Propellant Ignition
… features as well as the structure of opposed diffusion flame are studied next, followed by the study of opposed liquid jets and the gas layer at the interface. Lastly, effects of transport properties on gas phase kinetics are studied using impinging vapor sheets.</p> <p>In order to mitigate …
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Two-Dimensional Modeling of AP/HTPB Utilizing a Vorticity Formulation and One-Dimensional Modeling of AP and ADN
… AP and ADN, and a two-dimensional diffusion flame model has been developed to examine the flame structure above an AP/HTPB composite propellant. This work was part of an ongoing effort to develop theoretically based, <em>a priori</em> combustion models. The improved numerical model …
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Laser diagnostic investigation of the structure of steady and driven hydrogen jet diffusion flames
The structure of hydrogen jet diffusion flames has been investigated using coherent anti-Stokes Raman scattering (CARS) and laser-induced fluorescence (LIF) to obtain temperature and nitric oxide (NO) concentrations in steady laminar flames and during the interaction of induced fuel-side vortices …
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Investigation on weakly curved counterflow diffusion flames at infinitely fast chemistry
We investigate the behavior of a counterflow diffusion flame subject to a flow field comprising of a first order potential flow superimposed on a weak second order correction to the potential flow. An Arrhenius one-step irreversible reaction model at infinite Damkohler number and constant density …
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Studies on counterflow diffusion flames
Certain aspects of counterflow diffusion flames are addressed in the context of one-step Arrhenius-type global chemical reaction. The general Large-activation-energy asymptotic theory for diffusion flames is first revised and then applied to one dimensional counterflow diffusion flames with finite …
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High order numerical methods applied to the analysis of transport phenomena in combustion
… Through numerical solutions of the convection-diffusion operator and the wave operator it is shown, that this new family of finite difference methods achieves numerically stable solutions for any degree q < N and that these solutions present correct transient behaviours. This has motivated the …
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