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Showing 1 to 17 of 17 for “"OH* chemiluminescence"”.
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An investigation into the origin, measurement and application of chemiluminescent light emissions from premixed flames
The chemiluminescent species CH* and OH* are studied in premixed methane combustion to investigate the possible application of their light emissions in gas turbine combustion monitoring systems. The interpretation of integrated and local chemiluminescence measurements are shown to give important …
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A study of droplet velocity and diameter measurements in a reacting diesel spray produced by a flow-blurring injector
… Phase Doppler particle analyzer (PDPA) and OH* Chemiluminescence (CL) imaging techniques are employed as a diagnostic technique to monitor the spray characteristics in the cold and reacting regions of a diesel spray flame using a flow-blurring (FB) injector. PDPA is a well-known technique to …
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Flame front imaging and ignition performance of ultra-compact trapped-vortex combustor
… the ARC-S1, is investigated. Time-averaged OH* chemiluminescence was used to visualize flame anchoring and distribution inside the combustor. High-speed OH* PLIF imaging was conducted at two spanwise locations along the combustor cavity at 1∼3 atm, revealing an axial shift in flame …
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Blow-off in gas turbine combustors
… of the blow-off transient with 5 kHz OH* chemiluminescence, which allowed a quantification of the average duration of the blow-off transient. OH-PLIF images at 5 kHz for flames far from and close to extinction showed that the non-premixed flame intermittently lifts-off the bluff body, …
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Transient Phenomena in Annular Combustors
… for the system. Highspeed imaging (5 kHz) of OH* chemiluminescence revealed the peculiar flame shapes and behaviours that can be observed for different mixture velocities and equivalence ratios. Close to extinction, a pattern of blow-off and detachment of the flame was observed, due to …
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Determination of Flame Dynamics for Unsteady Combustion Systems using Tunable Diode Laser Absorption Spectroscopy
… through two measurements. Hydroxyl radical (OH*) chemiluminescence indicates the response in chemical reaction rate. Tunable Diode Laser Absorption Spectroscopy (TDLAS), centered over two water absorption features, allows a dynamic measurement of the product gas temperature. The response in …
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EXPERIMENTAL INVESTIGATION OF THE RESPONSE OF FLAMES WITH DIFFERENT DEGREES OF PREMIXEDNESS TO ACOUSTIC OSCILLATIONS
… fully premixed flames was examined. kHz OH* chemiluminescence was used to study qualitatively the heat release response of the flames, while kHz OH Planar Laser Induced Fluorescence (PLIF) was employed to understand the response of the flame structure and the behaviour of the various …
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Flow Field and Soot Formation Characteristics in Swirl-stabilized Non-premixed Turbulent Flames
… of planar laser-induced fluorescence of OH and OH* chemiluminescence were also made for methane and ethanol flames. The OH* field was further Abel-inverted to qualitatively locate the heat release zone. The flow field for all flames featured pronounced inner and outer recirculation zones …
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In-Cylinder Soot Oxidation in an Optically Accessible Automotive Diesel Engine
… small-bore optical diesel engines, which include OH* chemiluminescence, planar laser-induced fluorescence of hydroxyl (OH-PLIF) and planar laser-induced incandescence (PLII) imaging. Additionally, thermophoresis-based particle sampling techniques were implemented to obtain transmission electron …
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A Study of the Dynamics of Laminar and Turbulent Fully and Partially Premixed Flames
… resolved velocity perturbations, u', and the OH* chemiluminescence, as a measure of unsteady heat release rate, q'. The experimental data showed the corresponding flame dynamics to be fourth order in nature with a pure time delay. One of the resonance was shown to represent the pulsation of …
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Experimental investigation of unconfined bluff body stabilised flames with vapourised kerosene fuels
… and lean blow-off behaviour were studied with OH* chemiluminescence and high-speed (5 kHz) OH-PLIF imaging. Additionally, CH2O-PLIF imaging was used to assess the impact of fuel composition on the CH2O-layer thickness. As the flame approached LBO, fragmentation was observed downstream. The two …
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Understanding the development of a reacting fuel jet inside an automotive-size diesel engine using optical and laser-based diagnostics
… laser-induced fluorescence imaging of hydroxyl (OH-PLIF), fuel-PLIF, and line-of-sight integrated chemiluminescence imaging were performed for various combustion stages identified by the in-cylinder pressure traces and apparent heat release rates. These include stages of vaporising fuel …
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Experimental and numerical investigation of flameless pulverised coal combustion
… of air. The finding has been supported by OH* chemiluminescence imaging which revealed a suppression of ignition in the coal jet when N2 is used. With the investigated settings, NOx emissions are always above the legislative limit of 200 mg/m3 (stp). However, emissions close to the limit …
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An Experimental Investigation of Self-Excited Combustion Dynamics in a Single Element Lean Direct Injection (LDI) Combustor
… section. High-frequency measurements of OH*-chemiluminescence and OH-PLIF and velocity fields using PIV were obtained at a relatively stable, low equivalence ratio case and a less stable case at higher equivalence ratio. PIV measurements were performed at 5 kHz for non-reacting flow but …
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Lean Premixed Prevaporised Combustion for Microturbines
… are investigated using a gas analyser, 1D PDA, OH* chemiluminescence, and CH₂O-PLIF. Decreasing the global equivalence ratio, preheating the air, and recessing the fuel injection all reduced the NOₓ emissions. Cases without fuel injection recess or air preheat exhibit a conical-shaped heat …
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Impact of alternative jet fuels on gas turbine combustion systems
… National Jet Fuels Combustion Program. Average OH* chemiluminescence images are used to determine flame structure and dynamics with the goal of correlating spray characteristics with flame location. The alternative jet fuels studied exhibit unusual properties; a low cetane number fuel and a flat …
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Study of Ultra-low Emissions Diesel Combustion Systems by Synergetic Application of 3D-CFD and Single-Cylinder Engine
L'abstract è presente nell'allegato / the abstract is in the attachment