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Characterization of direct injected propane and iso-octane at engine-like conditions in a high-pressure spray chamber




Windell, Brye Thomas, author
Windom, Bret C., advisor
Olsen, Daniel, committee member
Venayagamoorthy, Subhas Karan, committee member

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This thesis focuses on the recommission, modification, and testing of a high-pressure spray chamber (HPSC) and its role in aiding the experimental and numerical examination of direct injection (DI) propane at various engine-like conditions to address fundamental limitations of achieving near diesel efficiencies in heavy duty on-road liquified petroleum gas (LPG) engines. The HPSC was reconstructed and is capable of incorporating optical diagnostic techniques including high-speed Schlieren and planar Mie scattering imaging. High-speed Schlieren was used to characterize the global spray morphology and vapor phase regions while planar Mie scattering allowed for individual plume resolution providing insights into the liquid regions of the spray. These optical imaging techniques unveiled propane's spray propagation was fed by flash boiling effects, spray collapse, and high degree of vaporization, unlike iso-octane. This resulted in a direct proportionality of propane's penetration length to temperature, an inversely proportional relationship to ambient pressure, and a direct proportionality to injection pressure. Contrary to propane, iso-octane's spray morphology exhibited minor changes as temperatures and pressures were varied. Due to these unique effects, flash boiling, spray collapse, and high degree of vaporization, propane is classified as an unconventional spray, dissimilar to iso-octane's spray morphology. Experimental testing provided corrections to numerical models that were developed to reproduce the under-expanded jet dynamics. The numerical modeling results were found to be sensitive to cone and inclusion angles. The current work serves as preliminary results for an experimental validation campaign which aid in the numerical model development for future heavy duty on-road LPG engines.


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imaging and visualization
computational fluid dynamics
liquefied petroleum gas


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