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Showing 1 to 20 of 28 for “"Planar laser-induced fluorescence (PLIF)"”.
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Hydroxyl-Radical Planar Laser-Induced Fluorescence Imaging of Turbulent Supersonic Combustion
… flow from non-intrusive hydroxyl radical (OH) planar laser-induced fluorescence (PLIF) images are presented. The OH PLIF images show instantaneous structures of turbulence in two combustor configurations at different fuel equivalence ratios in the University of Virginia Supersonic Combustion …
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Planar Laser Induced Fluorescence Experiments and Modeling Study of Jets in Crossflow at Various Injection Angles
Planar Laser Induced Fluorescence (PLIF) with acetone seeding was applied to measure the scalar fields of an axisymmetric freejet and an inclined jet-in-crossflow as applicable to film cooling. From the scalar fields, jet-mixing and trajectory characteristics were obtained. In order to validate the …
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Flame Surface Density Measurements and Curvature Statistics for Turbulent Premixed Bunsen Flames
… combustion was analyzed through CH (methylidyne) planar laser induced fluorescence (PLIF). Flame topography measurements in terms of flame surface density and curvature were calculated based on the flame front detected by the CH PLIF signal. The goal of this work was to investigate turbulent …
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Experimental investigations into high-altitude relight of a gas turbine
… a ground-based test facility. The application of laser diagnostics presents particular difficulties due to the large quantities of liquid fuel that impinge on the combustor walls during relight. Advances are made in the application of planar laser-induced fluorescence (PLIF) to monitor fuel …
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In Situ Flame Structure Imaging of Composite Propellants using High-Speed Planar Laser-Induced Fluorescence
… the models themselves. Recently, high-speed OH planar laser-induced fluorescence (PLIF) imaging has been applied to AP composite propellants to determine how microscale propellant flame structure varies with propellant formulation and pressure. Propellants with monomodal AP particle size …
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Remote three-dimensional temperature sensing using planar laser induced fluorescence : development and applications to microwave heated liquids
… thesis describes the development of a 3D imaging fluorescence thermometry system that was used to examine temporal and spatial variations in temperature within various aqueous solutions during their heating by microwave irradiation. The work provides one of the first experimentally-determined …
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Incident shock Mach number effects on Richtmyer-Meshkov mixing with simultaneous density and velocity measurements
… is measured using simultaneous quantitative Planar Laser-Induced Fluorescence (PLIF) and Particle Image Velocimetry (PIV) for the first time in a Richtmyer-Meshkov Mach number study, while exceptional experimental repeatability allows for isolation of Mach number effects. Investigated are the …
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Equivalence Ratio Gradient Effects on Local Flame Front Topology and Heat Release Rate in Stratified, Iso-Octane/Air Turbulent V-Flames
… approach was devised in which 3-pentanone tracer planar laser induced fluorescence (PLIF) was used to determine an analysis region of interest (ROI) within the flame. Iso-contours of equivalence ratio were traced up to the mean position of the flame front to define the width of the ROI, which was …
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Oblique Shock Wave Effects on Impulsively Accelerated Heavy Gas Column
… to elucidate the fundamental physics of shock-induced mixing for a simple three-dimensional interface. The interface studied consists of a gravity stabilized SF6-based heavy gas jet that produced a circular column with a diffuse interface into the surrounding air. The effects of density …
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Autoignition and emission characteristics of gaseous fuel direct-injection compression-ignition combustion
… in the flame was visualized utilizing Planar Laser Induced Fluorescence (PLIF). Single-shot OH-PLIF images revealed the stochastic nature of the autoignition process of non-premixed methane jets. Examination of the convergence of the ensemble-averaged OH-PLIF images showed that …
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Development of mesoscale burner arrays for next generation compact gas turbines
… burner array were visualized using OH and CH2O planar laser-induced fluorescence (PLIF). Next, a diffusion type mesoscale burner array was developed and investigated for small-scale combustion applications. Each burner element in the diffusion mesoscale burner array was equipped with its own …
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Liquid fuel transport into the cylinder in spark ignition engines
… a Phase Doppler Particle Analyzer (POPA) and a Planar Laser Induced Fluorescence (PLIF) technique were used to analyze in-cylinder liquid fuel droplets. From the measurements four major mechanisms of liquid fuel transport into the cylinder were identified using open and closed valve port fuel …
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Investigation of Ozone Initiated Ethylene Oxidation at Room Temperature: Chemistry and Flame Dynamics
… to the much more complicated kinetic pathways induced by direct reaction between fuel and O3, i.e., the ozonolysis reaction. In this dissertation, the O3 initiated ethylene (C2H4) oxidation is experimentally investigated at room temperature using multiple diagnostic methods. To accommodate the …
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Laser Diagnostics Applied to Lean Premixed Swirling Flames - Simultaneous Flow Field and Scalar Measurements
… of lean premixed swirling flames. Various laser-based optical diagnostic techniques were used to collect information under different operational conditions. Combined flow- and scalar field measurements were performed at high repetition rates for detailed studies of the turbulent flames. A …
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Fundamental studies of premixed combustion
… to study laminar flame propagation, while planar mie scattering (PMS) has elucidated important aspects of turbulent flame propagation. Thrbulent flame curvature has also been studied using planar laser induced fluorescence (PLIF) images. Spherically expanding flames propagating at constant …
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Development of high-speed laser diagnostics for the study of advanced propulsion systems
… this effort that the progressing capabilities of laser diagnostics open new possibilities of exploring the chemistry and fluid dynamics of complex reacting flows. The primary objective of this study is to develop and apply kHz-rate planar imaging to further our understanding of ignition and flame …
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Towards predicting dynamics in turbulent premixed combustion using PIV-PLIF measurements of flow-flame microstructure
… the micro-scale structure of the flow, while planar laser-induced fluorescence (PLIF) of OH radical is used to investigate the flame microstructure. Results demonstrate that combustion dynamics in wake-stabilized flames can be characterized using a single non-dimensional parameter that …
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Flame Structure and Emissions of Strongly-Pulsed Turbulent Diffusion Flames with Swirl
… due to the flow recirculation within the swirl-induced recirculation zone. The reaction zone structure, based on OH planar laser-induced fluorescence (PLIF) is broadly consistent with the observation of luminous flame structure for these types of flames. In many cases, the reaction zone exhibits …
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Reactive flow visualization through high-speed optical laser diagnostics
… was demonstrated using temporally-resolved laser diagnostics to visualize: 1) The turbulent flow field with particle image velocimetry (PIV); and 2) the distribution of combustion radicals, by planar laser-induced fluorescence (PLIF). This allows for the visualization of the flame surface …
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Swirl-stabilized lean-premixed flame combustion dynamics: An experimental investigation of flame stabilization, flame dynamics and combustion instability control strategies
… release and combustor acoustic modes where one amplifies the other in a feedback loop. This is a complex phenomenon which involves unsteady chemical kinetic, fluid mechanic and acoustic processes that can lead to unstable behavior and could be detrimental in ways ranging from faster part fatigue …
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