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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 18 of 18 for “"flame stability"”.
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Oxy-combustion of High Water Content Fuels
… the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the …
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The blow-off of burner flames
… is regarded as the primary variable controlling flame stability, and correlations have therefore been sought between burning velocity and blow-off flow rate. For this purpose, burning velocities have been determined by the cooled flat flame method, and blow-off flow rates have been measured for …
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Analysis of nitrogen oxide emissions produced during combustion of cracked-ammonia fuels
… in terms of combustion. This work compares the flame stability and NOx production of the two mixtures (with and without additional nitrogen). The range of operating conditions (equivalence ratio, fuel-hydrogen mole fraction, axial velocity) at which laminar burner-stabilized flames exist is …
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Swirl-stabilized lean-premixed flame combustion dynamics: An experimental investigation of flame stabilization, flame dynamics and combustion instability control strategies
… and power generation gas turbines, combustion instability remains one of the foremost technical challenges in the development of next generation lean premixed combustor technology. Combustion instability is the coupling between unsteady heat release and combustor acoustic modes where one …
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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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Dynamics of swirling jets and flames
… systems. However, the enhanced mixing and flame stability characteristics offered by swirling flow configurations are constrained by a relatively limited understanding of their dynamics, which continues to press the power and propulsion industry against the limits of reliable performance. …
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LARGE EDDY SIMULATION OF TURBULENT HYDROGEN FLAMES
… use introduces important challenges related to flame stability, strong differential diffusion effects, and increased nitrogen oxides (NOx) emissions. These issues are particularly critical in lean premixed conditions, which are commonly used to limit emissions but lead to complex …
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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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Lean Premixed Prevaporised Combustion for Microturbines
… Thus, this thesis explores the fuel flexibility, flame stability, structures, gas emissions, and droplet behaviour in LPP combustion at conditions relevant for microturbines. The first part of the thesis examines the effect of fuel choice using zero- and one-dimensional combustion simulations. The …
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Fuel flexible clean combustion of liquid fuels by a novel twin fluid atomization
… comparable to the small scale system in terms of flame appearance, emission levels, and static flame stability. Next, the scaled-up system’s combustion performance with glycerol fuel is investigated in laboratory and at industrial test site. Glycerol is extremely difficult to atomize because of …
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Development of mesoscale burner arrays for next generation compact gas turbines
… was designed to improve the overall combustion stability by exploiting flame-to-flame interactions under fuel-lean operation. Moreover, its design can be adjusted by scaling the element dimensions or array size to flexibly accommodate a wide range of combustion power outputs. The combustion …
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A Study of Greenhouse Gas Emissions and Performance of an Internal Combustion Engine Operating on Landfill Gas Blends as Fuel
… (CO), increases the energy density, improves the flame stability, and decreases emissions such as nitrogen oxides (NO<sub>x</sub>), CO, and unburned hydrocarbons (UHCs).<sup>1</sup> Due to the natural variability of the CO<sub>2</sub>/CH<sub>4</sub> ratio of the LFG from temperature and waste …
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Development and experimental analysis of a micro-flame ionization detector for portable gas chromatographs
… 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 with …
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Reactive flow visualization through high-speed optical laser diagnostics
… resulting in increased emissions and decreased flame stability. Hence, understanding and controlling the coupling between chemical kinetics and turbulence can lead to significant improvements in the design of combustion systems, improving their stability, efficiency and emissions …
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Self-sustained combustion of low grade solid fuels in a stagnation-point reverse-flow combustor
… to the combustor designer, for example reduced flame stability and poor combustion efficiency. Conventional solutions include preheating the incoming flow as well as co-firing with high-grade fuels. The SPRF combustor geometry has been chosen because it was demonstrated to operate stably on …
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Plasma-coupled microcombustion
… the chemical energy in a sub-millimeter scale flame, has the potential to provide a high energy density portable power source. Microburners have not realized this potential because of detrimental thermal and chemical surface effects. Investigation of macro-scale (>mm) flames has shown that …
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Turbulent partially premixed combustion: DNS analysis and RANS simulation
… difficulties involve, notably issues concerning flame stability and ignitability. A partially premixed system has been introduced to remedy these problems, however, our understanding on this combustion mode needs to be greatly improved to realise its full potential. This thesis aims to further …
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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 …