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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 16 of 16 for “"flame stabilization"”.
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Flame stabilization and propagation in high-velocity gas streams
Thesis (Sc.D.) Massachusetts Institute of Technology. Dept. of Chemical Engineering, 1948.
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Flame stabilization and mixing characteristics in a stagnation point reverse flow combustor
… velocities, species mixing, heat release and flame structure in an atmospheric pressure SPRF combustor with the help of various optical diagnostic techniques: OH PLIF, chemiluminescence imaging, PIV and Spontaneous Raman Scattering. Results indicate that the combustor is primarily stabilized …
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Impact of fuel and oxidizer composition on premixed flame stabilization in turbulent swirling flows : dynamics and scaling
… high-speed chemiluminescence to examine the flame macrostructure; high-speed Particle Image Velocimetry and OH Planar Laser Induced Fluorescence to probe the flow and flame microstructure. Numerical simulations were used to complement experiments and examine the complex three-dimensional …
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Swirl-stabilized lean-premixed flame combustion dynamics: An experimental investigation of flame stabilization, flame dynamics and combustion instability control strategies
… two decades which allows for visualization of flame structure and behavior. However, resolving both temporal and spatial structures from image-based experimental data can be very challenging. Thus, understanding flame dynamics remains a demanding task and the difficulties often lie in the …
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Development of a multi-scale projection method with immersed boundaries for chemically reactive flows and its application to examine flame stabilization and blow-off mechanisms
… tool to investigate the underlying mechanisms of flame stabilization and blow-off in canonical configurations. A second-order immersed boundary method for reacting flow simulations near heat conducting, grid conforming, solid object has been developed. The method is coupled with a block-structured …
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A Method for Measuring Spatially Varying Equivalence Ratios with Application to Thermoacoustics
Computed tomography for flame chemiluminescence emissions allows for 3D spatially resolved flame measurements to be acquired using a series of discrete viewing angle camera images. To determine fuel/air ratios, the ratio of excited radical species (OH*/CH*) emissions using chemiluminescence can be …
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Design and flow characterization of an indraft supersonic wind tunnel for scramjet testing
… isolators, fuel injection systems, ignition and flame stabilization, shock-boundary layer interaction, and aero-thermo-elastic interactions in scramjet vehicles. An indraft-type tunnel was chosen for its simplicity, low capital investment, and low power requirement. Its main features are large …
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Structure and Dynamics of a Reacting Jet Injected into a Vitiated Crossflow in a Staged Combustion System
… reacting jets and its corresponding influence on flame stabilization mechanism was investigated. The vitiated crossflow is produced by a low swirl burner (LSB) that imparted a swirling component to the crossflow and a bluff-body burner produced a uniform vitiated crossflow. The crossflow exhibits …
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Chemical kinetic modeling of oxy-fuel combustion of sour gas for enhanced oil recovery
… H2 S content in the fuel tends to improve flame stability through a lower ignition delay time. Water diluted oxy-fuel combustion leads to higher burning velocities at elevated pressures than CO 2 dilution or air combustion, which also facilitates flame stabilization. In a mixed CH4 and H2S …
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Simulations of turbulent swirl combustors
… Various aspects of the aerodynamics of swirling flames are investigated, such as precession or vortex formation caused by flow oscillations, as well as various combustion aspects such as localized extinctions and flame lift-off. All the above affect flame stabilization in different ways and are …
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Dynamics, stability and scaling of turbulent methane oxy-combustion
… this thesis we examine turbulent oxy-combustion flame stabilization physics at the large and small scales using experimental studies and numerical simulations. Experimental measurements are used to establish the stability characteristics of flame macrostructures in a swirl stabilized combustor. …
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Towards predicting dynamics in turbulent premixed combustion using PIV-PLIF measurements of flow-flame microstructure
… and inlet temperature. Dynamic pressure and flame chemiluminescence measurements are used to determine macro-scale characteristics such as the frequency, limit cycle amplitude and dynamic flame shape. High-speed, high-resolution particle image velocimetry (PIV) is used to quantify the …
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Investigation of a prototype industrial gas turbine combustor using alternative gaseous fuels
… examination of the actual burner, the laminar flame speed was measured for a range of gases. The measurement technique was based on Schlieren imaging which is a measure of the density gradient through a flame surface. A Bunsen type burner was used to measure the angle of a conical flame from …
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Large eddy simulations of premixed turbulent flame dynamics : combustion modeling, validation and analysis
… To achieve these objectives, lean premixed flames are generally preferred as they achieve efficient and clean combustion. A drawback of lean premixed combustion, however, is that the flames are more prone to dynamics. The unsteady release of sensible heat and flow dilatation in combustion …