Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 18 of 18 for “"OH-PLIF"”.
-
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 …
-
Development of high-speed laser diagnostics for the study of advanced propulsion systems
… planar laser-induced fluorescence (PLIF) is used to produce temporally resolved two-dimensional concentration fields of the molecular species targeted. Novel advancements in this study include kHz-rate hydroxyl radical (OH) PLIF of combustion phenomena within a supersonic wind tunnel …
-
Autoignition and emission characteristics of gaseous fuel direct-injection compression-ignition combustion
… predicted by FlameMaster simulation. OH radical distribution 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 …
-
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 …
-
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 …
-
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 …
-
Pyrolysis oil combustion characteristics and exhaust emissions in a swirl-stabilized flame
… hydroxyl radical planar induced fluorescence (OH-PLIF), fuel planar laser-induced fluorescence (Fuel-PLIF), and laser induced incandescence (LII). Spray characteristics have been investigated by employing Mie scattering and phase Doppler particle analysis(PDPA). Particulate emissions in …
-
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 …
-
Laser Diagnostic Techniques with Ultra-High Repetition Rate for Studies in Combustion Environments
… formaldehyde planar laser-induced fluorescence (PLIF) was carried out for the new design. Moreover, a novel multi-dye laser cluster has been set up. By pumping each of the four dye lasers individually using the Nd:YAG lasers in the multi-YAG cluster, tunable laser radiation with an ultra-high …
-
Flame stabilization and mixing characteristics in a stagnation point reverse flow combustor
… help of various optical diagnostic techniques: OH PLIF, chemiluminescence imaging, PIV and Spontaneous Raman Scattering. Results indicate that the combustor is primarily stabilized in a region downstream of the injector that is characterized by low average velocities and high turbulence levels; …
-
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 …
-
Measurements of the structure of turbulent premixed and stratified methane/air flames
… slot and swirl burners. Concurrent cross-planar OH-PLIF allows thermal gradients to be angle corrected to their three-dimensional values. Finally, non-reacting and reacting velocity fields complete the flame database. The behavior of major species concentrations in the slot and swirl burner with …
-
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 …
-
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, …
-
Flame Structure and Emissions of Strongly-Pulsed Turbulent Diffusion Flames with Swirl
… 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 discontinuities at the instantaneous flame tip in the early …
-
Experimental Investigation of Large Scale Aerodynamics on Soot Emissions in Swirling Flows
… using both Ethylene and an alternative Gevo alcohol-to-jet kerosene fuel referred to as Jet C-1. The goal is to extend the understanding presently available in the literature on dilution air by investigating the impact of systematically varying the amount and location of downstream radially …
-
Structure and Dynamics of a Reacting Jet Injected into a Vitiated Crossflow in a Staged Combustion System
… particle image velocimetry (PIV) and OH planar laser-induced fluorescence (PLIF) were performed at five measurement planes perpendicular to the jet axis. Transverse jets composed of premixed natural gas and H2 diluted with N2 were injected through a tube protruding into the crossflow. …
-
Simulating Extinction and Blow-off in Kerosene Swirl Spray Flames
… from the LES are fairly similar to experimental OH* and OH-PLIF with Mie scattering results, however there are significant differences in location of peak heat release rate and further work is required for validation of the simulations against experiments. CH is discussed as a promising …