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.
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Showing 1 to 20 of 21 for “"spray combustion"”.
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Modeling and Simulation of High-Density Spray Combustion
… and low-emissions can be realized in combustion engines that operate at high-pressures and low-temperatures conditions (high densities). The design of such engines relies on accurate models of the physical processes involved. Three areas of concern are multi-phase phenomena, the …
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Modelling of Spray Combustion with Doubly Conditional Moment Closure
Turbulent spray combustion is characterised by a strong coupling of evaporation, mixing and chemical reaction. This leads to a wide spectrum of combustion regimes, where self-propagating premixed flames and diffusion-controlled non-premixed flames may occur simultaneously within the same flame. The …
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Spray combustion diagnostics with tracer-based laser-induced fluorescence imaging
… Reihe von optischen Diagnostiktechniken für die Sprayanalyse, die auf dem Prinzip der laserinduzierten Fluoreszenz (LIF) von Tracern basieren, auf ihre Anwendbarkeit und ihre Grenzen hin untersucht. Die Methoden wurden dazu auf unterschiedliche Spraysysteme angewendet: Von der Anwendung in …
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Time-gated ballistic imaging through scattering media with applications to liquid spray combustion
Includes bibliographical references (pages 119-130).
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Effects of Thermoacoustic Oscillations on Spray Combustion Dynamics with Implications for Lean Direct Injection Systems
… Intuitively, development of effective active combustion control methodologies is strongly dependent on the knowledge of the onset and sustenance of thermoacoustic instabilities. Specially, non-premixed spray combustion environment pose additional challenges due to the inherent unstable …
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Combustion characteristics of alternative liquid fuels
… acetone, methane and methane/acetone. The spray atomization characteristics of a plain-jet airblast atomizer are investigated using a phase Doppler anemometry (PDA) under non-reacting conditions. The droplet size and velocity distribution of biodiesels are compared to conventional fuels. …
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Droplet Drag Modeling on Spray Conditions
… of large droplets. In applications such as spray combustion, droplets of various sizes are generated and move with the flow. Large droplets tend to deform in the flow, and they have complex interactions with the flow because of this deformation. To better model spray, the physical …
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Modelling of group combustion of droplets in a spray fuel cloud
Release and combustion of a spray cloud in an atmosphere is a phenomenon encountered in a wide range of applications. For solution of a set of problems which is connected with ecology, theory of combustion and explosion, engine design, fire safety, etc. the knowledge of spray combustion behaviour …
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Evaporation of biomass pyrolysis oil as single droplets
… oils are usually introduced into the burner as sprays of droplets; therefore, the evaporation behaviour of individual fuel droplet has an important role in understanding of the combustion characteristics of the droplets in spray combustion and in the burner performance. Single droplet …
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Characterization of spray and combustion of diesel-alcohol blends in a constant volume chamber
In this study, the spray combustion characteristics of Acetone-Butanol-Ethanol (ABE)/ Diesel blends was investigated. An optical-accessible constant volume chamber capable of controlling ambient temperature, pressure and oxygen concentration was used to mimic the environmental conditions inside a …
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Numerical simulation of combustion and unburnt products in dual-fuel compression-ignition engines with multiple injection
… natural gas can enable promising approaches to combustion engine design. In particular, the combination of low reactivity natural gas and high reactivity diesel may allow for optimal operation as a reactivity-controlled compression ignition (RCCI) engine, which has potential for high efficiency …
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Rural electrification from local resources : biomass pyrolysis oil combustion in a direct injection diesel engine
… as potentially feasible renewable fuels. Combustion of pyrolysis oils in diesel engines has been scarcely studied, and the few studies which have been performed indicate that these fuels exhibit excessively long ignition delay, rendering them dependant on auxiliary ignition sources for …
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Numerical Investigation on Shape Impact of Deformable Droplets on Evaporation and Combustion: Method Development and Characterization
Inspired by the dilute spray regime in spray combustion, this dissertation explores the evaporation and combustion of an isolated droplet. Under a highly convective environment inside a gas combustor, due to imbalance of inertial and surface tension forces, the droplets of larger size in sprays …
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Direct numerical simulation of droplet-laden isotropic turbulence
… ranging from rain formation to oil spills to spray combustion. The physical mechanisms of droplet-turbulence interaction are largely unknown, especially when compared to that of solid particles. Compared to solid particles, droplets can deform, break up, coalesce and have internal fluid …
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The Role of Fuel Droplets in Laminar Flame Propagation
In all likelihood, combustion will be needed in the foreseeable future to supply energy to a growing population. Yet the burning of fossil fuels to power modern life is both harmful and unsustainable. Faced with this dilemma, the design of clean and efficient combustion systems is a global …
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Oxy-combustion of High Water Content Fuels
… we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are …
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Numerical investigation on the effect of fuel droplets on premixed laminar flames
This thesis explores the combustion of liquid fuels, a process widely applied in industry, with a particular focus on laminar premixed flames containing fuel droplets. Despite their prevalence, these flames have not been extensively studied due to challenges in measuring key parameters and …
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Ignition and propagation mechanisms of spray flames
… analysis of the phases of ignition in sprays is carried out in a controlled, well-characterised experiment: the initiation of a spherically expanding flame in a turbulent droplet-laden jet by a laser spark. A revision of definitions of ignition-related terms is proposed based on a …
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