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1
Gavaises, Manolis. "Modelling of diesel fuel injection processes." Thesis, Imperial College London, 1997. http://hdl.handle.net/10044/1/8681.
Повний текст джерела
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Meeboon, Non. "Design and Development of a Porous Injector for Gaseous Fuels Injection in Gas Turbine Combustor." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427813298.
Повний текст джерела
3
Negrete, Justin E. "Effects of different fuels on a turbocharged, direct injection, spark ignition engine." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/59952.
Повний текст джерелаАнотація:
Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 65).
The following pages describe the experimentation and analysis of two different fuels in GM's high compression ratio, turbocharged direct injection (TDI) engine. The focus is on a burn rate analysis for the fuels - gasoline and E85 - at varying intake air temperatures. The results are aimed at aiding in a subsequent study that will look at the benefits of direct injection in turbocharged engines, ethanol's knock suppression properties, and the effects of ethanol concentration in gasoline/ethanol blends. Spark sweeps were performed for each fuel/temperature combination to find the knock limit and to assess each fuels' sensitivity to spark timing and temperature. The findings were that E85 has lower sensitivity to spark timing in terms of NIMEP loss for deviation from MBT timing. A 5% loss in NIMEP was seen at 3° of spark advance or retard for gasoline, whereas E85 took 5' to realize the same drop in NIMEP. Gasoline was also much more sensitive to intake air temperature changes than E85. Increasing the intake air temperature for gasoline decreased the peak pressure, however, knock onset began earlier for the higher temperatures, indicating that end-gas autoignition is more dependent on temperature than pressure. E85's peak pressure sensitivity to spark timing was found to be about 50% lower than that of gasoline and it displayed much higher knock resistance, not knocking until the intake air temperature was 130°C with spark timing of 30° bTDC. These results give some insight into the effectiveness of ethanol to improve gasoline's anti-knock index. Future experiments will aim to quantify charge cooling and anti-knock properties, and determine how ethanol concentration in gasoline/ethanol blends effects this knock suppression ability.
by Justin E. Negrete.
S.B.
4
Park, Talus. "Dual fuel conversion of a direct injection diesel engine." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=460.
Повний текст джерелаАнотація:
Thesis (M.S.)--West Virginia University, 1999.Title from document title page. Document formatted into pages; contains x, 96 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 61-62).
5
Fletcher, Philip James. "Determination of additives in fuels using automated flow injection analysis with chemiluminescence detection." Thesis, University of Plymouth, 2002. http://hdl.handle.net/10026.1/2068.
Повний текст джерелаАнотація:
The overall objective of this thesis was to develop field deployable instrumentation for the selective, sensitive determination of additives in diesel fuels using flow injection with chemiluminescence detection. The target analytes were the detergent dodecylamine and the lubricity additive P655. Chapter One describes the types of additives that are used in fully formulated diesel fuels in order to improve performance and outlines the need for robust analytical methods to be able to detect their presence / absences in fuels at the point of distribution, i.e. at the petrol pump. Flow injection (FI), and chemiluminescence (CL) are described as suitable techniques for sample preparation and detection respectively. The application of FI-CL for the quantitative determination of various analytes is reviewed, with the focus on real sample matrices. Finally the technique of solid phase extraction is discussed as a means of selective analyte preconcentration / matrix removal prior to FI-CL detection Chapter Two describes the development and optimisation (both univariate and simplex) of an FI-CL method for the determination of dodecylamine in acetonitrile / water mixtures using the catalytic effect of amines on the peroxyoxalate / sulphorhodamine 101 CL reaction. The linear range for dodecylamine was 0 - 50 mg Lˉ¹ with a detection limit of 190 µg Lˉ¹ and RSDs typically < 4 %. The effect of indigenous diesel compounds on the CL response is also investigated. Chapter Three investigates the applicability of the method developed in Chapter Two to determine dodecylamine in diesel fuels. Solid phase extraction was needed prior to analysis by FI-CL. The development of a solid phase extraction that is compatible with the FI-CL system is detailed. GC-NPD and GC-MS analysis are used in order to validate the solid phase extraction procedure. A range of diesel fuels have been spiked with an additive package containing dodecylamine and have been analysed off-line using FI-CL. Recoveries for all diesel fuels analysed were < 72 % and all fuels could by identified from the corresponding base fuel. Chapter Four describes the design and construction of a fully automated on-line solid phase extraction flow injection chemiluminescence analyser for the determination of dodecylamine in diesel fuel. Details of the automation and programming using LabVIEW are described. Results obtained using the automated on-line system are compared with results obtained using off-line SPE with FI-CL detection from Chapter Three. Recoveries for all fuels except SNV were < 71 %, and all fuels except SNV could be positively identified from the corresponding base fuels. No significant differences were found between the on-line and off-line results (within 95 % confidence limits). Chapter Five investigates the feasibility of determining the lubricity additive P655 in diesel fuel using FI-CL. The optimisation and development of a method using the competing reactions of periodate with alcohols and periodate with the CL oxidation reaction with pyrogallol is discussed, and the development of a solid phase extraction procedure for the extraction of P655 from an organic matrix is described. The limit of detection for P655 using SPE without preconcentration was 860 mg Lˉ¹ and was linear in the range 0 - 10000 mg Lˉ¹ (R² = 0.9965).
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Hergueta, Santos-Olmo Cruz. "Modern fuels and catalytic technologies for low emissions in gasoline direct injection engines." Thesis, University of Birmingham, 2018. http://etheses.bham.ac.uk//id/eprint/8432/.
Повний текст джерелаАнотація:
The requirements for controlling Particulate Matter (PM) and gaseous emissions emitted from gasoline direct injection (GDI) engines, especially under cold start conditions, and the introduction of bio-alcohols fuels in the market demands the development of novel efficient aftertreatment technologies. Understanding the PM characteristics from the combustion of different fuels it is a key step in the design of next generation of catalysts and aftertreatment systems, including three-way catalyst (TWC) and catalyst coated or not gasoline particulate filters (GPFs). The research study presented in this thesis provides a detailed understanding of the synergies between bio-alcohols derived fuels combustion in GDI engines and novel aftertreatment technologies on the control of PM and gaseous emissions. The effect of the physico-chemical properties of bio-alcohol fuel blends on combustion and emissions at warm steady-state and cold start engine conditions has been investigated. Bio-butanol fuel blend has been further explored at different engine loads in combination with exhaust gas recirculation (EGR) technology. An extensive characterization of the PM emissions has been carried out using several methodologies and techniques such as high resolution transmission electron microscopy (HRTEM), thermogravimetric analysis (TGA), scanning mobility particle sizer (SMPS) and Raman spectroscopy. The combustion of bio-alcohols resulted in a significant reduction of 60% - 80% of PM emissions with the modification in their structural characteristics, leading to agglomerates with smaller primary particles (≈1-3 nm) and fractal dimensions and, soot with higher tortuosity (≈3.1 %) as TEM revealed. Under cold start event, bioalcohols emitted more reactive and less mature soot (i.e. higher organic content and impurities) as found from TGA and Raman analysis compared to soot emitted from gasoline fuel combustion. The TWC activity was improved between 4.3% and 1.5% in the exhaust stream from the bio-alcohols combustion. The aftertreatment architectures, including either coated GPFs or not and arrangement in the exhaust (i.e. upstream or downstream of the TWC) has shown a significantly impact on the TWC activity, reducing light-off temperatures up to 20°C. Catalytic GPF showed high performance to efficiently filter PM and removed gaseous emissions from GDI combustion with acceptable pressure drop.
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White, Timothy Ross Mechanical & Manufacturing Engineering Faculty of Engineering UNSW. "Simultaneous diesel and natural gas injection for dual-fuelling compression-ignition engines." Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2006. http://handle.unsw.edu.au/1959.4/25233.
Повний текст джерелаАнотація:
The introduction of alternative fuels such as natural gas is likely to occur at an increasing rate. The dual-fuel concept allows these low cetane number fuels to be used in compression-ignition (CI, diesel) type engines. Most CI engine conversions have pre-mixed the alternative fuel with air in the intake manifold while retaining diesel injection into the cylinder for ignition. The advantage is that it is simple for practical adaptation; the disadvantage is that good substitution levels are only obtained at midload. A better solution is to inject both the alternative and diesel fuels directly into the cylinder. Here, the fuel in the end-zone is limited and the diesel, injected before the alternative, has only a conventional ignition delay. This improves the high-end performance. Modern, very high pressure diesel injectors have good turndown characteristics as well as better controllability. This improves low-end performance and hence offers an ideal platform for a dual-fuel system. Several systems already exist, mainly for large marine engines but also a few for smaller, truck-sized engines. For the latter, the key is to produce a combined injector to handle both fuels which has the smallest diameter possible so that installation is readily achieved. There exists the potential for much improvement. A combined gas/diesel injection system based on small, high pressure common-rail injectors has been tested for fluid characteristics. Spray properties have been examined experimentally in a test rig and modelled using CFD. The CFD package Fluent was used to model the direct-injection of natural gas and diesel oil simultaneously into an engine. These models were initially calibrated using high-speed photographic visualisation of the jets. Both shadowgraph and schlieren techniques were employed to identify the gas jet itself as well as mixing regions within the flow. Different orientations and staging of the jets with respect to each other were simulated. Salient features of the two fuel jets were studied to optimise the design of a dual-fuel injector for CI engines. Analysis of the fuel-air mixture strength during the injection allowed the ignition delay to be estimated and thus the best staging of the jets to be determined.
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Alves, Francisco José. "Produção e fornecimento de vapor de etanol para motor de combustão interna operando com combustível pré-vaporizado." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/18/18147/tde-09022008-164934/.
Повний текст джерелаАнотація:
O motor a álcool pré-vaporizado tem potencial para ser uma alternativa mais eficiente e menos poluente aos motores a álcool convencionais. Nele, o combustível é vaporizado com calor rejeitado pelo próprio motor e admitido na fase gasosa, aproveitando-se das vantagens dos motores com combustíveis nessa fase sem alguns dos seus inconvenientes. O projeto foi aperfeiçoado buscando viabilidade técnica e econômica para sua instalação em veículos automotores. Água do sistema de arrefecimento cede calor para a ebulição do combustível. As novas tecnologias para injeção de combustíveis gasosos contribuem para esse objetivo, bem como o desenvolvimento de um sistema sustentável e auto-ajustável de geração de vapor de etanol que usa a água do sistema de arrefecimento. Conseguiu-se maior eficiência em quase todos os regimes de funcionamento estudados, bem como meios de reduzir as principais emissões automotivas indesejáveis.Pre-vaporized ethanol engine (PVEE) has potential to be more efficient and less pollutant than conventional ethanol-powered engines. In it, fuel is vaporized with heat rejected by engine itself and intook in gaseous form, taking advantage of this kind of fuel but without some of its inconveniences. The PVEE project was polished looking for economical and technical liability to future use in automotive vehicles. New gaseous fuel injection technologies contribute to this goal, together the development of a sustainable and self-adjustable ethanol vapor generating system who uses water from engine\'s cooling systems. Better efficiency was achieved in almost all investigated regimes, as well as were found ways to reduce the main undesirable automotive emissions.
9
Ibrahim, Mahmoud I. Ph D. "Design and Development of a Novel Injector (Micro-Mixer) with Porous Injection Technology (PIT) for Land-Based Gas Turbine Combustors." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1522419312986562.
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10
Liu, Quan. "Planar laser induced fluorescence imaging and analysis with ethanol blended fuels in a direct injection spark ignition engine." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/14786.
Повний текст джерелаАнотація:
The currently reported thesis was concerned with visualisation of the charge homogeneity and cyclic variations within the planar fuel field near the spark plug in an optical spark ignition engine fitted with an outwardly opening central direct fuel injector. Specifically, the project examined the effects of fuel type and injection settings, with the overall view to understanding some of the key mechanisms previously identified as leading to particulate formation in such engines. The three fuels studied included a baseline iso-octane, which was directly compared to two gasoline fuels containing 10% (E10) and 85% (E85) volume of ethanol respectively. The engine was a bespoke single cylinder with Bowditch style optical access through a flat piston crown. Charge stratification was studied over a wide spectrum of injection timings using the Planar Laser Induced Fluorescence (PLIF) technique, with additional variation in charge temperature due to injection also estimated when viable using a two-line PLIF approach. Overall, both gasoline-ethanol fuels generally exhibited a higher degree of stratification, albeit at least partly alleviated with elevated rail pressures. Under both warm and cold liner conditions the E10 fuel showed clear evidence of fuel droplets persisting up until ignition. Interestingly, with late injection timing the repeatability of the injection was superior (statistically) with higher ethanol content in the fuel, which may have been associated with the higher charge temperatures aiding control of the evaporation of the main mass of alcohol. The findings were corroborated by undertaking a comprehensive study of the influence of varying fuel type and injection settings on thermodynamic performance and engine-out emissions during firing operation, with additional gas exchange effects also influencing the optimum fuel injection timings.
11
Bonanos, Aristides Michael. "Scramjet Operability Range Studies of an Integrated Aerodynamic-Ramp-Injector/Plasma-Torch Igniter with Hydrogen and Hydrocarbon Fuels." Diss., Virginia Tech, 2005. http://hdl.handle.net/10919/28847.
Повний текст джерелаАнотація:
An integrated aerodynamic-ramp-injector/plasma-torch-igniter of original design was tested in a Mâ = 2, unvitiated, heated flow facility arranged as a diverging duct scramjet combustor. The facility operated at a total temperature of 1000 K and total pressure of 330 kPa. Hydrogen (H2), ethylene (C2H4) and methane (CH4) were used as fuels, and a wide range of global equivalence ratios were tested. The main data obtained were wall static pressure measurements, and the presence of combustion was determined based on the pressure rises obtained.
Supersonic and dual-mode combustion were achieved with hydrogen and ethylene fuel, whereas very limited heat release was obtained with the methane. Global operability limits were determined to be 0.07 < Ï < 0.31 for hydrogen, and 0.14 < Ï < 0.48 for ethylene. The hydrogen fuel data for the aeroramp/torch system was compared to data from a physical 10º unswept compression ramp injector and similar performance was found with the two arrangements. With hydrogen and ethylene as fuels and the aeroramp/plasma-torch system, the effect of varying the air total temperature was investigated. Supersonic combustion was achieved with temperatures as low as 530K and 680K for the two fuels, respectively. These temperatures are facility/operational limits, not combustion limits.
The pressure profiles were analyzed using the Ramjet Propulsion Analysis (RJPA) code. Results indicate that both supersonic and dual-mode ramjet combustion were achieved. Combustion efficiencies varied with Ï from a high of about 75% to a low of about 45% at the highest Ï . With a theoretical diffuser and nozzle assumed for the configuration and engine, thrust was computed for each fuel. Fuel specific impulse was on average 3000 and 1000 seconds for hydrogen and ethylene respectively, and air specific impulse varied from a low of about 9 sec to a high of about 24 sec (for both fuels) for the To = 1000K test condition.
The GASP RANS code was used to numerically simulate the injection and mixing process of the fuels. The results of this study were very useful in determining the suitability of the selected plasma torch locations. Further, this tool can be used to determine whether combustion is theoretically possible or not.Ph. D.
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Glaad, Gustaf. "Pressurizing of high-pressure fuel system forsingle cylinder test cell." Thesis, Karlstads universitet, Institutionen för ingenjörsvetenskap och fysik (from 2013), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-74432.
Повний текст джерелаАнотація:
This master thesis covers the development of a high-pressure fuel system for compression ignitedfuels such as diesel and diesel-like fuels that will be deployed into a single cylinder test cell at AVLMTC Södertälje, Sweden. The test cell is used by AVL to conduct research and testing of new fuelsfor their customers and this new fuel system will widen the span of fuels able to be tested by theequipment.This thesis focuses on pumping and pressurizing of the fuel, ensuring that all ingoing materialsare non-corrosive in this environment and compatible with the necessary fuels and lastly a safetyanalysis of the system with respect to operator and process safety. Other aspects of the projectsuch as mass flow measurements and fuel conditioning is covered in a sister thesis Mass flowrate measurement of compression ignition fuels in high-pressure stand-alone pump unit for singlecylinder test cell written by C. Aksoy [1].The goal of this thesis project was to deliver a finished manufactured fuel system and if the timeallowed for it, also validate its performance and finally installing and incorporating it into the singlecylinder test cell. The development process started with the writing of a product specificationoutlining the requirements and request on the product in a specification of requirements matrix andrelate these to product properties of the system using a quality function deployment (QFD) matrix.This document was then used as a base for further advancement in developing concepts to solveeach product property and weighing these concepts against each other using Pugh’s matrices. Thechosen concepts were then further developed, a flow chart for the system was developed as well asfuel lines and other supporting components were analyzed and chosen.In the end the high-pressure fuel pump from Scania’s XPI fuel system were chosen as well asa pressure transducer in the HP1000 series from ESI. Within the time frame of this thesis, theproject did not end up getting finished to the degree planned, but due to time constraints werehalted before starting manufacturing of the system. Some minor component choices remained aswell as documentation such as drawings and finalizing the physical layout of the system remained.All information regarding the remaining work needed to finalize the project and deploying thesystem in the test cell were outlined and with more time, the fuel system should fulfill its purposeof allowing testing and research of compression ignited fuel to be possible in the test cell.Kontentan för denna mastersavhandling är utvecklingsprocessen för ett högtrycksbränslesystemför kompressionsbränslen såsom diesel och diesellika bränslen som kommer att installeras i enencylindertestcell hos AVL MTC Södertälje, Sverige. Testcellen används av AVL för forskningoch testning av nya bränslen åt deras kunder och detta nya bränslesystem kommer att utöka typernaav bränslen som kan testas med utrustningen till att inkludera kompressionsantända bränslen.Denna avhandling fokuserar på utvecklingen av tillförseln och trycksättnigen av bränslet, säkerställnigenav att ingående material är icke-korrosiva i den avsedda miljön och kompatibla med allanödvändiga bränsletyper och slutligen en säkerhetsanalys av systemet med avseende på operatörsochprocessäkerhet. Andra aspekter såsom massflödesmätning och bränslekonditionering presenterasi systeravhandlingen Flödesmätning och konditionering av högtryckantända bränslen för encylindertestcellskriven av C. Aksoy [1].Målet med denna avhandling var att leverera ett färdigtillverkad bränslesystem och om tiden tillät,även validera systemets prestanda och slutligen integrera och installera systemet i testcellen. Utvecklingsprocesseninleddes med att skriva en produktspecifikation som innehöll en sammanställningav kundens krav och önskemål för produkten och relaterade dessa till produktegenskaper med hjälpav en quality function deployment (QFD) matris. Detta dokument användes vidare som en bas förfortsatt utveckling av produkten i konceptgenereringsprocessen och för att väga de olika konceptenmot varandra med hjälp av Pugh’s matriser. De valda koncepten blev sedan analyserade ytterligare,ett flödesschema för de ingående komponenterna framtaget och övriga sekundära komponenteranalyserade och valda.Till slut valdes högtrycksbränslepumpen från Scanias XPI system och en tryckgivare från HP1000-serien från ESI. Inom tidsramen för avhandlingen färdigställdes aldrig projektet till den grad somhade planerats, men blev istället avbrutet innan tillverkningen av systemet han påbörjas på grund avtidsbegränsningar. Vissa sekundära komponentval, dokumentation såsom ritningar och färdigställningav den fysiska layouten av systemet kvarstod vid avhandlingens slut. All information angåendeallt nödvändigt fortsatt arbete för att färdigställa projektet och integrera systemet i encylindertestcellendokumenterades och med mer tid borde bränslesystemet kunna uppfylla sitt syfte att möjliggöratestning och forskning av kompressionsbränslen i testcellen.
13
Micó, Reche Carlos. "DEVELOPMENT OF MEASUREMENT AND VISUALIZATION TECHNIQUES FOR CHARACTERIZATION OF MIXING AND COMBUSTION PROCESSES WITH SURROGATE FUELS." Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/58991.
Повний текст джерелаАнотація:
[EN] The development and optimization of new combustion modes is nowadays an important research field, to reduce the pollutant emissions of the reciprocating internal combustion engines. Their development requires the use of a wide variety of experimental and theoretical tools, which make it possible to know and understand their fundamentals. In this context the main objective of this Thesis is framed: the development and optimization of measuring and visualization techniques, to reach the level of accuracy and detail required for current and future studies of that kind. The work has been based on the characterization of the diesel diffusion combustion to be able to focus the study on the methodological part, thanks to the extensive knowledge available on this combustion mode.
The work has been divided in two main blocks. The first one is focused on the characterization of evaporation and air-fuel mixture formation processes. For this purpose, a new technique has been developed and applied, based on the light absorption by the fuel molecules (UV-VIS LAS), which allows measuring the vapour fuel local concentration within a diesel spray. It has been optimized to be applied under operating conditions similar to those found in a compression ignition engine with fuels whose optical properties are not optimal, but which are interesting for research due to its simplicity. Moreover, a new methodology has been developed for measuring the absorption coefficient of the fuels, under similar operating conditions (i.e. pressure and temperature) than those found within the combustion chamber of a compression ignition engine. Results have been analysed in detail, to be able to define the limitations and reliability of the methodology proposed.
The second block corresponds to the characterization of the combustion process and the soot formation. For this purpose, a complex optical set-up has been developed which made it possible to simultaneously apply the three most used techniques that can be found in literature for soot measuring within a diesel flame: Laser Extinction Method, 2-Colour Pyrometry and Laser-Induced Incandescence. Results obtained by means of the three techniques have been compared in detail, not only to identify the main advantages and drawbacks of each technique, but also their reliability under different operating conditions.[ES] El desarrollo y optimización de nuevos modos de combustión constituye actualmente un campo importante de investigación, para reducir la emisión de contaminantes en motores de combustión interna alternativos. Su desarrollo requiere del uso de gran variedad de herramientas experimentales y teóricas, que permitan conocer y comprender sus fundamentos. En este contexto se enmarca el objetivo principal de esta Tesis: la mejora y el desarrollo de técnicas de visualización y medida, para alcanzar el nivel de detalle y la precisión requeridos para estudios actuales y futuros de esta índole. El trabajo se ha basado en la caracterización de la combustión diésel por difusión para poder centrar el estudio en la parte metodológica, gracias al amplio conocimiento disponible sobre este modo de combustión. El trabajo se ha dividido en dos apartados principales. El primero de ellos se centra en la caracterización de los procesos de evaporación y formación de la mezcla aire-combustible. Para ello, se he desarrollado y puesto en práctica una técnica basada en la absorción de luz por parte de las moléculas de combustible (UV-VIS LAS), que permite medir la concentración local de combustible evaporado en el seno de un chorro diésel. Esta ha sido optimizada para ser aplicada en condiciones de operación semejantes a las de un motor de encendido por compresión con combustibles cuyas propiedades ópticas no son óptimas, pero que son de gran interés para investigación dada su simplicidad. Además, se ha desarrollado una metodología para la medida del coeficiente de absorción de los combustibles, bajo las mismas condiciones de operación (presión y temperatura) que las que se dan en la cámara de combustión de un motor de encendido por compresión. Los resultados obtenidos se han analizado con detalle, para poder definir los límites y la fiabilidad de la metodología propuesta. El segundo apartado corresponde a la caracterización del proceso de combustión y la formación de hollín. Para ello, se ha desarrollado un montaje óptico complejo que ha permitido aplicar de forma simultánea las tres técnicas más utilizadas en la literatura para la medida del hollín en una llama diésel: Método de Extinción Láser, Pirometría 2-Colores e Incandescencia Inducida por Láser. Los resultados obtenidos mediante las tres técnicas han sido comparados detalladamente, no sólo para identificar las principales ventajas e inconvenientes de cada técnica, sino también la fiabilidad de las mismas para distintas condiciones de operación.
[CAT] El desenvolupament y optimització de nous modes de combustió constitueixen actualment un camp important d'investigació, para reduir la emissió de contaminants en motors de combustió internat alternatius. El seu desenvolupament requereix del us de gran varietat de ferramentes experimentals i teòriques, que permeten conèixer i comprendre els seus fonaments. En este context s'emmarca l'objectiu principal d'esta tesi: la millora i el desenvolupament de tècniques de visualització i mesura, per a conseguir el nivell de detall i la precisió requerits per a estudis actuals i futurs d'esta índole. El treball s'ha basat en la caracterització de la combustió dièsel per difusió per a poder centrar l'estudi en la part metodològica, gràcies a l'ampli coneixement disponible sobre este mode de combustió. El treball s'ha dividit en dos apartats principals. El primer d'ells se centra en la caracterització dels processos d'evaporació i formació de la mescla aire-combustible. Per això, s'ha desenvolupat i posat en pràctica una tècnica basada en la absorció de llum per part de les molècules de combustible (UV-VIS LAS), que permet mesurar la concentració local de combustible evaporat en el si d'un esprai dièsel. Esta ha sigut optimitzada per a ser aplicada en condicions d'operació semblants a les d'un motor d'encesa per compressió i combustibles amb propietats òptiques que no son les òptimes, però els quals són de gran interés en investigació donada la seua simplicitat. A més, s'ha desenvolupat una metodologia per a la mesura del coeficient d'absorció dels combustibles, a les mateixes condicions d'operació (pressió i temperatura) que les que es donen en la cambra de combustió d'un motor d'encesa per compressió. Els resultats obtinguts s'han analitzat amb detall, per a poder definir els límits i la fiabilitat de la metodologia proposada. El segon apartat correspon a la caracterització del procés de combustió i la formació de sutja. Per a això, s'ha desenvolupat un muntatge òptic complex que permés aplicar de forma simultània les tres tècniques més utilitzades en la literatura per a la mesura de la sutja en una flama dièsel: Mètode d'Extinció Làser, Pirometria 2-Colors i Incandescència Induïda per Làser. Els resultats obtinguts per mitjà de les tres tècniques han sigut comparats detalladament, no sols per a identificar els principals avantatges i inconvenients de cada tècnica, sinó també la fiabilitat d'aquestes per a distintes condicions d'operació.
Micó Reche, C. (2015). DEVELOPMENT OF MEASUREMENT AND VISUALIZATION TECHNIQUES FOR CHARACTERIZATION OF MIXING AND COMBUSTION PROCESSES WITH SURROGATE FUELS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/58991
TESIS
14
Ibrahim, Umar. "Characterization of Biodiesel Blends Effects on Aftertreatment Systems and Aftertreatment-based Blend Level Estimation." The Ohio State University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=osu1451906418.
Повний текст джерела
15
Viera, Sotillo Juan Pablo. "Experimental study of the effect of nozzle geometry on the performance of direct-injection diesel sprays for three different fuels." Doctoral thesis, Universitat Politècnica de València, 2017. http://hdl.handle.net/10251/81857.
Повний текст джерелаАнотація:
This thesis studies the influence of internal nozzle flow characteristics over a large spectrum of experimental conditions and diagnostics. Experiments were carried out for two nozzle geometries---cylindrical and conical single hole nozzles---and three different fuels. Two of the fuels are pure components---n-heptane and n-dodecane---while the third fuel consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. Measurements include a complete hydraulic characterization consisting of instantaneous injection rate and spray momentum flux measurements; a high-speed visualization of isothermal liquid spray; a high-speed visualization of the evaporative inert spray, imaging liquid and vapor phases simultaneously and finally, a high-speed visualization of the high temperature reactive spray, imaging vapor phase and OH* chemiluminescence for each injection event. All high-temperature diagnostics were performed in a continuous flow test chamber that allows an accurate control on a wide range of thermodynamic conditions (up to 1000 K and 15 MPa).
The experimental findings from this work, and the large database obtained (available for download at: http://www.cmt.upv.es/DD01.aspx), could be used to validate CFD models that could help the community understand the fundamental driving mechanisms behind these observations.En esta tesis se estudia la influencia del flujo interno sobre un amplio espectro de condiciones y diagnósticos experimentales. Se realizaron experimentos para dos geometrías de tobera---toberas cilíndrica y cónica de un único orificio---y tres combustibles. Dos de los combustibles son puros---n-heptano y n-dodecano--- mientras el tercero es un combustible sustituto que consiste en una mezcla de tres componentes que busca representar mejor las propiedades físicas y químicas del diesel. Las medidas incluyen una caracterización hidráulica completa, compuesta por tasa de inyección y cantidad de movimiento instantáneas; una visualización de alta velocidad del chorro líquido isotermo; una visualización de alta velocidad del chorro inerte evaporativo, con captura simultánea de las fases líquida y vapor y, finalmente, una visualización del chorro reactivo a alta temperatura, con captura de la fase vapor y la quimioluminiscencia del radical OH* para cada evento de inyección. Todos los diagnósticos en condiciones de alta temperatura fueron realizados en una maqueta de alta presión y temperatura de flujo constante que permite controlar con precisión un rango amplio de condiciones termodinámicas (hasta 1000 K y 15 MPa). Los resultados experimentales y la gran base de datos obtenida en este trabajo (disponible en: http://www.cmt.upv.es/DD01.aspx), podrían ser utilizados para validar modelos CFD detallados que podrían ayudar a la comunidad científica a entender mejor los mecanismos fundamentales que producen los resultados observados.
Aquesta tesi estudia la influència del flux intern sobre un gran espectre de condicions i diagnòstics experimentals. Es van realitzar experiments per a dos geometries de tovera---toveres ci¿líndrica i cónica amb un únic orifici---i tres combustibles. Dos dels combustibles són purs---n-heptà i n-dodecà--- mentre el tercer combustible consisteix en una mescla de tres components que formen un combustible substitut que busca representar millor les propietats físiques i químiques del dièsel. Les mesures inclouen una caracterització hidràulica completa, composta per taxa d'injecció i quantitat de moviment instantanis; visualització d'alta velocitat del doll líquid isoterme; visualització d'alta velocitat del doll inert evaporatiu, capturant simultàniament les fases líquid i vapor i, finalment, una visualització del doll reactiu a alta temperatura, capturant la fase vapor i la quimioluminiscència del radical OH per a cada esdeveniment d'injecció. Tots els diagnòstics en condicions d'alta temperatura van ser realitzats en una insta¿lació d'alta pressió i temperatura amb flux constant que permet controlar amb precisió un ampli rang de condicions termodinàmiques (fins a 1000 K i 15 MPa). Els resultats experimentals i la gran base de dades obtinguda en aquest treball (disponible a la web en: http://www.cmt.upv.es/dd01.aspx), podrien ser utilitzats per tal de validar models CFD detallats que podrien ajudar a la comunitat científica a entendre millor els mecanismes fonamentals que produeixen aquestes observacions.
Viera Sotillo, JP. (2017). Experimental study of the effect of nozzle geometry on the performance of direct-injection diesel sprays for three different fuels [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/81857
TESIS
16
Сукачов, Іван Іванович. "Поліпшення паливної економічності форсованих дизелів шляхом узгодження характеристик вприскування палива та форми камери згоряння". Thesis, НТУ "ХПІ", 2005. http://repository.kpi.kharkov.ua/handle/KhPI-Press/3555.
Повний текст джерелаАнотація:
Дисертація присвячена вивченню особливостей процесів сумішоутворення і згоряння у форсованих дизелях та вибору раціональних параметрів характеристик вприскування палива і форми камери згоряння. Об'єктом дослідження є процеси сумішоутворення та згоряння в судових і тепловозних дизелях типу ЧН25/27, ЧН25/34, ЧН26/34, ЧН26/27 і ЧН32/32. Розглянуті специфіка і особливості процесів сумішоутворення і згоряння у форсованих дизелях. Виявлені основні причини зниження швидкостей випаровування і згоряння збільшених циклових порцій палива і визначені методи і способи узгодження характеристик вприскування палива і форми камери згоряння. Розроблені математична модель циклу дизеля, комплекс програмного забезпечення для розрахунку робочого процесу, в тому числі, характеристик вприскування палива, розподілу палива в струмені та камері згоряння, характеристик сумішоутворення і згоряння. Виконані розрахунково-експериментальні дослідження для погодження характеристик вприскування палива і камер згоряння, які дозволили обгрунтовано вибрати раціональні параметри паливної апаратури, характеристик вприскування палива і форми камери згоряння, що забезпечили зниження експлуатаційної витрати палива в досліджених дизелях на 1,5-3%.Dissertation is devoted to the study of features of processes formations of working mixture and combustion in the forced diesels and choice of rational parameters of descriptions of injection of fuel and form of combustion chamber. It is a research object judicial Ships and diesel engines diesels of dimension: 25/27, 25/34, 26/34, 26/27 and 32/32. A specific and features of processes of formations of working mixture and combustion is considered in the forced diesels. The found out the principal reasons of decline of speeds of evaporation and combustion of megascopic cyclic portions is fuels and certain methods and methods of concordance of descriptions of injection of fuel and form of combustion chamber. Developed mathematical model of cycle of diesel, complex of software for the calculation of working process, in that number, descriptions of injection of fuel, division of fuel in a stream and combustion, descriptions of formations of working mixture and combustion chamber. Executed calculation-experimental researches for the concordance of descriptions of injection of fuel and chambers combustions, which allowed grounded to choose the rational parameters of fuel apparatus, descriptions of injection of fuel and form of combustion chamber, which provided the decline of operating cost of fuel in the explored diesels on 1,5-3%.
17
Nerva, Jean-Guillaume. "An Assessment of fuel physical and chemical properties in the combustion of a Diesel spray." Doctoral thesis, Universitat Politècnica de València, 2013. http://hdl.handle.net/10251/29767.
Повний текст джерелаАнотація:
With the slow but ineluctable depletion of fossil fuels, several avenues are currently being explored in order to define the strategic boundaries for a clean and sustainable energetic future, while accounting for the specificities of each sectors involved. In regard to transport applications, alternative fuels may represent a promising solution, at least at short or middle term, such as the International Energy Agency foresees that their share could account for 9% of the road transport fuel needs by 2030 and 27 % by 2050, with the potential resources to reach 48% beyond. If they have already been included in significant blending proportions with conventional fossil fuel in most of the occidental countries, their introduction also coincides with a long-time established program of continuously more drastic standards for engine emissions of NOX and PM, now even further demanding by the seek for combustion efficiency aiming at reducing CO2 emissions.
While several works discuss the alternative fuels effect on exhaust emissions when used directly in production Diesel engines, results and analysis are sometimes contradictory, depending sometimes on the conditions in which they were obtained, and the causes of these results remain unclear. Therefore, in order to better understand their effect on the combustion processes, and thus extract the maximum benefits from these fuels in the optimization of engine design and calibration, a detailed comprehension of their spray and combustion characteristics is essential.
The approach of this study is mostly experimental and based on an incremental methodology of tests aiming at isolating injection and combustion processes with the objective to identify and quantify the role of both fuel physical and chemical properties at some key stages of the Diesel combustion process. After obtaining a detailed characterization of their properties, five fuels have been injected in an optical engine enabling a sharp control of the thermodynamic eNerva, J. (2013). An Assessment of fuel physical and chemical properties in the combustion of a Diesel spray [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/29767
Palancia
18
Lawrence, Jacob David. "Design and development of a high pressure ED95 fuel delivery system for a single cylinder test cell engine." Thesis, KTH, Fordonsdynamik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-286351.
Повний текст джерелаАнотація:
Bio-fuels, being the primary alternative to the fossil fuels, used in the internal combustion engines are subjected to constant development. The development of alternative Ethanol Diesel (ED95) formulations at AVL Motortestcenter AB has demanded a test facility capable of evaluating the combustion quality of these specimens. A test cell capable of evaluating fuels operating on the compression ignition concept was required for this reason. The aim of this thesis is to develop a high pressure fuel delivery system for a single cylinder test cell engine. The literature review conducted offered knowledge on stages involved in the development of the fuel and the operation of high pressure fuel systems for engines operating on the Diesel concept. Knowledge was acquired on phenomenon such as pressure fluctuations and information regarding engine test cells was familiarised. Scania's XPI fuel system being the designated fuel system for the test cell was studied and adaptations required for its implementation in the single cylinder test cell was investigated. Based on the information acquired, recommendations for the set up of the high pressure fuel system for the single cylinder test cell engine are mentioned.Förnyelsebara biobränslen är det primära alternativet till fossila bränslen för användning i interna förbränningsmotorer och är under ständig utveckling. För den fortsatta utvecklingen av etanoldiesel (ED95) genom provning av nya formuleringar vid AVL Motortestcenter AB krävs ett lämplig testupplägg. Förbränningskvalitetsutvärderingen kräver en avancerad testcell där bränslets förbränningsegenskaper kan utvärderas. Målet med detta arbete var att utveckla ett högtrycksbränslesystem lämpligt för en singelcylindrig forskningsmotor som arbetar enligt kompressionständningsprincipen (dieselprincipen). Litteraturstudien samlade kunskap om bränsleutveckling samt kunskap om dieselmotorers högtrycksbränslesystemen, dess uppbyggnad och utmaningar. Kunskap om fenomen som tryckoscillationer och kavitation i bränslesystem samt förståelse för motorprovcellers uppbyggnad införskaffades. Scanias XPI bränslesystem, som forskningsmotorns högtrycks- bränslesystem ska efterlikna, studerades och adaptioner för att passa till encylinderkörningar i provcell utvärderades. Baserat på informationen ges rekommendationer på hur Scanias XPI system kan implementeras och justeras för att fungera i AVL’s singelcylinderprovcell.
19
Mandokhot, Mohit Atul. "Development of Predictive Gasoline Direct Fuel Injector Model for Improved In-cylinder Combustion Characterization." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1534517269503352.
Повний текст джерела
20
MEICENHEIMER, HEIDI L. "INDEPENDENT STAGE CONTROL OF A CASCADE INJECTOR." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1155655108.
Повний текст джерела
21
Henkel, Sebastian. "Effects of fuel properties, injector conditions and impingement on the sprays of direct injection engines." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/58209.
Повний текст джерелаАнотація:
The concept of gasoline direct injection engines is at the forefront of modern research. Two major concerns with the design are the incomplete evaporation of the injected fuel that leads to increased engine-out emissions and the process of injector fouling caused by the direct exposure of the injector to the flame. The latter also reduces the lifetime of this component and also increases emissions at the same time. These are critical issues for OEMs as emissions legislations around the world demand increasingly stricter thresholds. The research presented is split into two separate parts, to tackle both concerns. First, a series of fuel blends and operating conditions and their effect towards spray shape, droplet size and velocity as well as wall wetting will be investigated in a dedicated injection chamber. In order to quantify the amount of fuel that forms a liquid deposit on the surface a novel measurement technique is presented. The data gathered in these measurements is then used to show trends between the blends investigated and to give suggestions for potential improvements of future engine designs and modified engine operating conditions to reduce the amount of particulate emissions. In the second part of the research a series of injectors that were previously fouled are investigated. The fouling caused a significant increase of particulate emissions in test engines and the focus here is to provide possible explanations for this drift. Additionally, some of the injectors were treated with a detergent fuel which reverted the change in emissions. A comparison of these injectors shall provide information about potential applications of such blends and how they would benefit the longevity of modern engines.
22
Baniasad, Mohammad Saeid. "Analysis of fuel injection rate in diesel injection systems." Thesis, Imperial College London, 1994. http://hdl.handle.net/10044/1/7439.
Повний текст джерела
23
Slator, Duncan. "Fuel injector spray diagnostic development." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/17488.
Повний текст джерелаАнотація:
New technologies are constantly developing towards the goal of increasing the performance of gas turbine engines while reducing pollutant emissions. The design of the combustion system is vital in the drive to reduce pollutants in order to meet legislative targets. As part of this, the fuel injector is crucial in preparing the fuel for combustion through atomization and correct mixing with the air flow. Thus, it is desirable to develop techniques to allow the analysis of performance in these key criteria and improve the understanding of both fuel injector aerodynamics and fuel atomisation. Particle Image Velocimetry (PIV) allows for spatially resolved velocity data of flow fields to be recorded and therefore enables the inspection of flow behaviour.
24
Fairbrother, R. J. "Computer simulation of fuel injection for direct-injection diesel engines." Thesis, Imperial College London, 1994. http://hdl.handle.net/10044/1/8618.
Повний текст джерела
25
Mohamad, Taib Iskandar. "Development of a spark plug fuel injector for direct injection of natural ags in spark ignition engine." Thesis, Cranfield University, 2006. http://hdl.handle.net/1826/4436.
Повний текст джерелаАнотація:
In the name of God, The Most Gracious, The Most Merciful. By His will, this thesis has
been completed as another episode of knowledge seeking and contribution.
The author wishes to express a greatest gratitude to the academic supervisor for this project,
Dr. Matthew Harrison and Professor Douglas Greenhalgh for their warmth, continuous
guidance and support, priceless knowledge and expertise, and kindly understanding.
Secondly, author's deepest appreciation to Dr. Mark Jermy, the initial supervisor for this
project, for his ideas, understanding, support, availability and generosity for providing
assistance both in author's academic and private life.
To my mother and father whose supplications and encouragements have given me strength
to complete this work. To my family whose support during this course of studies has given
me comfort. To my parents in-law and siblings in-law, thank you for your support.
My dearest gratitude to the beloved wife, Ira for standing by my side and giving me
continuous support throughout this course of study and the hardship of life due to it. Your
sacrifice is priceless. To my children, Balgis, Naufal, Nadiyah and Safiyah, you are my source
of inspirations.
A special thank to Dr. Glenn Sherwood, Tim Lee, Brian Scully, Richard Kennewell, Alan
Hutching, and all others for providing technical supports during the experiment works.
To Andreas, Eudoxios, Anni, Edouard, Fatiha, Alessio, Andy and Adam, I thank you all for
the friendship and helps during my studies.
26
Mohamad, Taib Iskandar. "Development of a spark plug fuel injector for direct injection of natural gas in spark ignition engine." Thesis, Cranfield University, 2006. http://dspace.lib.cranfield.ac.uk/handle/1826/4436.
Повний текст джерелаАнотація:
The use of methane in spark ignition engines is mainly due to its cleaner emissions and relatively low price. However, when methane replaces gasoline in the externally mixing carburettor or port injection engine, power is reduced and upper speed is limited. These are because the burning velocity of methane is slower than of gasoline, and some air is displaced in the intake manifold in order to compensate the low density methane. The problem can be mitigated when fuel is directly injected into the combustion chamber after the intake valve closes. This results in an increased volumetric efficiency, a higher absolute heating value of mixture and a faster burning rate. The work presented in this thesis aims to develop a conversion system that enables methane to be directly injected into the combustion chamber of a spark ignition engine without modifying the original structure of the engine. The system, named as Spark Plug Fuel Injector (SPFI) combines a fuel injector with a spark plug. A fuel path is drawn along the periphery of the spark plug body to deliver the injected fuel to the combustion chamber. The system was installed and tested on a Ricardo E6 single cylinder engine with compression ratio of 10.5: 1. Cylinder pressures were taken as the main indicator of the engine performance and selected indicated performance were presented. A set of port injected data for the engine running on methane was also taken in order to provide a comparison of performance with SPFI direct injection. Results show that the indicated performance of the SPFI methane direct injection at the tested speed was lower than the optimised methane port injection operation. This was mainly due to the quality of air-fuel mixing, which is a result of spatial and temporal limitation of direct injection operation. Flow visualization using the PLIF method shows that even though sufficient gas jet penetration from SPFI injection nozzle was achieved, the cone angle was very narrow. The conclusion from imaging experiments implies poor mixing, hence the performance suffers drawback. However, with direct injection, volumetric efficiency is increased ands combustion duration is faster. These two factors are desirable for engine performance improvement. SPFI has proven to be a practical and low cost conversion to methane. Even though the performance is lower than port injection, its benefits are significant. As the SPFI design is simple and requires no modification to the original structure of the converted engine.
27
Brombacher, Eric J. "Flow visualisation of natural gas fuel injection." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0010/MQ33968.pdf.
Повний текст джерела
28
Duan, Shang You. "Fuel injection control for an IC engine." Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335571.
Повний текст джерела
29
Reveille, T. "Study of fuel injection and mixture formation for a gasoline direct injection engine." Thesis, Cranfield University, 2005. http://hdl.handle.net/1826/4288.
Повний текст джерелаАнотація:
Future requirements for lower automotive emissions have lead to the development of
new internal combustion (IC) engine technologies. Gasoline Direct Injection (GDI), for
example, is one of these promising new IC engine concepts. It offers the opportunity of
increased efficiency through unthrottled operation. However, the realisation of this
concept is critically dependent on the in-cylinder mixture formation, especially in the
late injection/lean operation mode. Ideally, this would require a precise stratification of
the in-cylinder fuel-air mixture in 3 distinct zones: an ignitable pocket located at the
spark plug, surrounded by a stoichiometric mixture of fuel and air, encompassed by air.
To enable this stratification, the GDI concept utilises advanced injector technology.
Phase Doppler Anemometry (PDA), Planar Laser-Induced Fluorescence (PLIF) and the
combination of PLIF and Mie scattering in the Laser-Sheet Dropsizing (LSD)
technique, have been applied to sprays in the past to obtain dropsize information and
study the mixture formation process. These new GDI sprays are denser, their droplet
sizes are smaller and they evaporate faster, and as such, place us at the limit of the
validity of these measurements techniques.
The diagnostics were applied to a GDI spray in a pressure vessel for realistic in-cylinder
conditions, ranging from supercooled to superheated environments. Tracer evaporation
issues in the PLIF technique were resolved by using a dual tracer system. The study
showed that the LSD technique provided good quantitative data in low evaporation
regimes. In highly evaporating regimes, the technique still gave reliable dropsize data
for the early stages of the injection, but was limited afterwards by vapour-phase
contribution to the fluorescence signal. Variations between PDA data and LSD results
also suggested a deviation of the Mie scattering signal from the assumed d2 dependence.
This was further investigated and was found to be true for small droplets (d/?. <0.2). This
source of error might be improved by using a different observation angle. High density
seriously compromises the accuracy of PDA, whilst its effect through multiple
scattering is of second order for the LSD technique. In low evaporating regimes, LSD has the overall advantage of being a 2-D measurement
technique, and will yield data with a maximum error of 30% in dense parts of the spray
where PDA data is totally unreliable. If the spray evaporates quickly, PLIF by itself is
an appropriate tool for following the air-fuel mixture, because short droplet lifetimes
limit the 2-phase flow behaviour of the spray.
Particle Image Velocimetry (PIV), the LSD technique and equivalence ratio LIF
measurements were applied to a BMW single cylinder optical GDI engine. The early
injection operation showed no particular issues. However, the results obtained in the late
injection highlighted the poor mixing and inappropriate stratification.
30
Rose, Dean Wilfred. "Mixture preparation in a spark-ignition engine during fast load transients." Thesis, Brunel University, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239301.
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31
Fardad, Davood. "Investigation of evaporation of hydrocarbon droplets on heated surfaces." Thesis, Brunel University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296173.
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32
McShane, P. M. "Optimization of the morphological, mechanical and rheological properties of novel polypropylene/ethylene-octene copolymer blends for automotive fuel line protection applications." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268405.
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33
Salters, David Gregory. "Studies of the break-up zones of diesel sprays using an improved conductivity probe methodology." Thesis, University of Manchester, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387222.
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34
Shelby, Michael H. (Michael Howard). "PLIF investigation of the fuel distribution in gasoline direct injection fuel sprays." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43930.
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35
Watson, Cody. "Modeling of pressure transients in fuel injection lines." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/16869.
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36
Abdelkarim, Nazar B. H. "Numerical modelling of direct-injection gasoline fuel sprays." Thesis, Loughborough University, 2005. https://dspace.lboro.ac.uk/2134/34055.
Повний текст джерелаАнотація:
This thesis presents a numerical study of the break-up and atomisation of gasoline fuel sprays injected into atmospheric flow conditions and environments related to combustion chamber conditions. Calculations of the fuel break-up process were achieved by four different models: Taylor Analogy Break-up (TAB), the wave instability theory (WAVE), the Hybrid Sheet-TAB and the Hybrid WAVE-FIPA models. The TAB model relates the break-up process to the droplet oscillations; whereas the WAVE models calculate the fuel break-up from the unstable waves on the droplet surface. The modified version of the TAB model, called the Hybrid Sheet-TAB model delays the start of the break-up further downstream from the nozzle tip. A new hybrid model, the WAVE-FIPA model, divides the spray atomisation processes into a primary stage, where the WAVE model is used, and a secondary stage, which is simulated using experimental correlations to calculate the break-up time for the low Weber number droplets.
37
Meah, Nabil Haque. "Modelling for turbulent autoignition with split fuel injection." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/417852/.
Повний текст джерелаАнотація:
Split-injection is applied in automotive diesel engines in order to control heat release and pollution production. Injecting fuel prior to the main fuel injection, known as pilot injection, increases premixing and tends to reduce NOx emission. Injecting a portion of the fuel after the main injection has potential for reducing particulate emissions. In order to meet increasingly stringent emission and fuel consumption regulations, modern automotive diesel injectors have been developed with the capacity to deliver of the order of ten separate injection pulses during a single engine stroke. Simulation methods for split-injection engines are required in order to develop more advanced injection strategies with two or more separate fuel-injections. A range of additional combustion applications involve mixing and combustion between multiple streams such as Exhaust Gas Recirculation (EGR) and dual fuel injections. Modelling for the turbulent combustion interactions in multi-stream problems is developed in this thesis in the context of Conditional Moment Closure (CMC) methods. The CMC approach provides modelling of chemical processes in turbulent flows by linking composition fluctuations to the variation of a small number of conditioning variables such as mixture fraction. In order to achieve good accuracy, the conditioning variables must be chosen to minimise compositional fluctuations around the conditional mean. Split-injection diesel engine operation results in complex combustion behaviour in which a single conditioning variable may be insufficient. However multiple-conditioned moment closures, or even double conditional moment closures (DCMC) have not been exploited previously. The objective of this study is to identify the most appropriate conditioning variables for modelling of split-injection diesel engines and to formulate, validate and demonstrate a practical implementation of the DCMC approach for engine-relevant simulations. The thesis begins by developing a new formulation of the DCMC approach that is applicable to a general set of non-conserved conditioning variables, and a set of numerical solution approaches is demonstrated and verified. The choice of conditioning variables is then investigated through direct numerical simulations of autoignition in a turbulent flow with up to three separate fuel injections. In the case with a single injection, fluctuations around the mixture fraction-conditioned mean arise due to variation in mixture fraction dissipation rate affecting the progress of ignition differently at different points in space. In cases with multiple injections, the repeated addition of unreacted fuel also adds to fluctuations around the conditional mean. The high level of conditional fluctuations leads to large errors when employing singly-conditioned first-order conditional moment closure. Alternative doubly conditional moment closure approaches are tested using a priori and a posteriori analyses. Single conditioned first order closure gives extremely poor agreement with the DNS, and the study indicates that double conditioning on mixture fraction and progress variables, such as the sensible enthalpy, outperforms double conditioning on multiple mixture fractions. The feasibility of the zero-dimensional DCMC approach for practical predictive design calculations is then assessed further through simulations of n-heptane spray ignition in constant volume research vessels with single or multiple injections. The experimental flows are simulated by coupling the zero-dimensional first order double conditional moment closure (0D-DCMC) with a commercial CFD code and an efficient Operator Splitting solution method is demonstrated. The predictions show the same trends as the experimental observations, however ignition delays and lift off lengths agree with the measurements only approximately. Reasons for the discrepancies include the uncertainty in the chemical modelling as well as in the ambient temperature surrounding the spray in the experiments. The modelling of conditional cross-scalar dissipation rate is also found to have a significant influence on the flame evolution, with the limiting cases of modelling corresponding to zero correlation or unity correlation between mixture fraction and progress variable giving unrealistic predictions. Conditional cross-dissipation rate modelling corresponding to negative unity correlation gives reasonable predictions, and an argument for why negative mixture fraction-progress variable correlation is expected to be dominant in autoignitive lifted jet flames involving multiple fuel injections is presented. Other aspects of modelling uncertainty with regard to conditional dissipation rates, presumed joint mixture fraction-progress variable probability density functions and first order source term closures will also contribute to the model error, and further development of models suitable for spray autoignition cases would be beneficial. In comparison with the established three-dimensional singly-conditioned moment closure (3D-CMC), the 0D-DCMC model is a promising approach which is expected to be substantially faster than the 3D-CMC approach in most problems of engineering interest. Not withstanding the imperfect predictions, the ability of the zero-dimensional DCMC to describe the whole split-injection process and to provide new insight into the mechanisms involved is encouraging: this implies that only a few DCMC control volumes may be needed in order to model a wide range of flows involving very complex physics, of which split-injection is just one example, and the DCMC approach is therefore recommended for further development.
38
Tsimis, Charalampos. "Fuel jet injection and supersonic mixing for scramjets." Thesis, Imperial College London, 2007. http://hdl.handle.net/10044/1/8722.
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39
Savic, Sasha. "Liquid fuel spray characteristics." Thesis, University of Brighton, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324470.
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40
Vafamehr, Hassan. "A study of pre-ignition and knock in an optical spark ignition engine." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/17562.
Повний текст джерелаАнотація:
The currently reported work involved fundamental study of auto-ignition under unusually high knock intensities in an optical spark ignition engine. The single cylinder research engine adopted included full bore overhead optical access capable of withstanding continuous peak in-cylinder pressure and knock intensity of up to 150 bar and 60 bar respectively. Heavy knock was deliberately induced under relatively low loads (5 bar IMEP) using inlet air heating up to 66 °C and a primary reference fuel blend of reduced octane rating (75 RON). High speed chemiluminescence natural light imaging was used together with simultaneous heat release analysis to evaluate the combustion events. The key out comes of this study could be listed as follow: • Proof and improved understanding of multi centred auto-ignition events under high KIs • Improved understanding of the potential pitfalls of over-fuelling for heavy knock suppression • Optical validation of 'natural' oil droplet release and on-off behaviour of knocking cycles Multiple centred auto-ignition events were regularly observed to lead in to violent knocking events, with knock intensities above 140 bar observed. The ability to directly image the events associated with such high magnitude of knock is believed to be a world first in a full bore optical engine. The multiple centred events were in good agreement with the developing detonation theory to be the key mechanism leading to heavy knock in modern downsized SI engines. The accompanying thermodynamic analysis indicated lack of relation between knock intensity and the remaining unburned mass fraction burned at the onset of the auto-ignition. Spatial analysis of the full series of images captured demonstrated random location of the first captured auto-ignition sites during developing auto-ignition events. Under such circumstances new flame kernels formed at these sites, with initial steady growth sometimes observed to suppress the growth of the earlier spark initiated main flame front prior to violent end gas auto-ignition. It was found that pre-ignition most commonly initiated in the area surrounding the exhaust valve head and resulted in a deflagration that caused the overall combustion phasing to be over advanced. In the cycles after heavy knock, droplets of what appeared to be lubricant were sometimes observed moving within the main charge and causing pre-ignition. These released lubricant droplets were found to survive within the combustion chamber for multiple cycles and were associated with a corresponding "on-off" knocking combustion pattern that has been so widely associated with super-knock in real downsized spark ignition engines. This research also concerned with improving understanding of the competing effects of latent heat of vaporization and auto-ignition delay times of different ethanol blended fuels during heaving knocking combustion. Under normal operation the engine was operated under port fuel injection with a stoichiometric air-fuel mixture. Additional excess fuel of varied blend was then introduced directly into the end-gas in short transient bursts. As the mass of excess fuel was progressively increased a trade-off was apparent, with knock intensity first increasing by up to 60% before lower unburned gas temperatures suppressed knock under extremely rich conditions (γ=0.66). This trade-off is not usually observed during conventional low intensity knock suppression via over-fuelling and has been associated with the reducing auto-ignition delay times outweighing the influence of charge cooling and ratio of specific heats. Ethanol had the highest latent heat of vaporization amongst the other fuels directly injected and was more effective to reduce knock intensity albeit still aggravating knock under slightly rich conditions. Overall, the results demonstrate the risks in employing excess fuel to suppress knock deep within a heavy knocking combustion regime (potentially including a Super-Knock regime).
41
Jelercic, David. "Experiments in annular combustors." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251891.
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42
Allen, Nancy. "Finite element modelling of eddy currents in nonlinear and moving media." Thesis, University of Bath, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362151.
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43
Comer, Adam Landon. "Optimisation of liquid fuel injection in gas turbine engines." Thesis, University of Cambridge, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607844.
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44
Asay, Rich. "A Five-Zone Model for Direct Injection Diesel Combustion." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/100.
Повний текст джерелаАнотація:
Recent imaging studies have provided a new conceptual model of the internal structure of direct injection diesel fuel jets as well as empirical correlations predicting jet development and structure. This information was used to create a diesel cycle simulation model using C language including compression, fuel injection and combustion, and expansion processes. Empirical relationships were used to create a new mixing-limited zero-dimensional model of the diesel combustion process. During fuel injection five zones were created to model the reacting fuel jet: 1) liquid phase fuel 2) vapor phase fuel 3) rich premixed products 4) diffusion flame sheath 5) surrounding bulk gas. Temperature and composition in each zone is calculated. Composition in combusting zones was calculated using an equilibrium model that includes 21 species. Sub models for ignition delay, premixed burn duration, heat release rate, and heat transfer were also included. Apparent heat release rate results of the model were compared with data from a constant volume combustion vessel and two single-cylinder direct injection diesel engines. The modeled heat release results included all basic features of diesel combustion. Expected trends were seen in the ignition delay and premixed burn model studies, but the model is not predictive. The rise in heat release rate due to the diffusion burn is over-predicted in all cases. The shape of the heat release rate for the constant volume chamber is well characterized by the model, as is the peak heat release rate. The shape produced for the diffusion burn in the engine cases is not correct. The injector in the combustion vessel has a single nozzle and greater distance to the wall reducing or eliminating wall effects and jet interaction effects. Interactions between jets and the use of a spray penetration correlation developed for non-reacting jets contribute to inaccuracies in the model.
45
Lake, Timothy Hugh. "Gasoline combustion systems for improved fuel economy and emissions." Thesis, University of Brighton, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302289.
Повний текст джерелаАнотація:
This document is the statement of independent and original contribution to knowledge represented by the published works in partial fulfilment of the requirements of the University of Brighton for the degree of Doctor of Philosophy (by publication). The thesis reviews the impact of research work conducted between 1992 and 1998 on various concepts to improve the economy and emissions of gasoline engines in order to address environmental and legislative pressures. The research has a common theme, examining the dilution of the intake charge (with either recycled exhaust gas [EGR], excess air, or the two in combination) in both conventional port injected [MPI] and direct injection [G-DI] combustion systems. After establishing the current status of gasoline engine technology before the programme of research was started, the thesis concentrates on seven major pieces of research between 1992 and 1996. These explored a subsequently patented method of applying recycled exhaust gas to conventional port injected gasoline engines to improve their economy and emissions whilst staying compatible with three-way catalyst systems. Nine other studies are reviewed which took place between 1992 and 1999 covering other methods of improving gasoline engines, specifically direct injection and two-stroke operation. Together, all the studies provide a treatise on methods to improve the gasoline engine and the thesis allows a view from a broader perspective than was possible at the time each study was conducted. In particular, the review identifies a range of strategies that use elements of the research that can be used to improve economy and emissions. Four major categories of systems researched include: conventional stoichiometric MPI engines developed to tolerate high EGR rates [CCVS]; two-stroke G-DI engines; G-DI engines operating stoichiometrically with high EGR rates; and G-DI engines operating with high dilution from both excess air and EGR. The findings of the studies illustrate that although good fuel economy improvements and emissions can be obtained with EGR dilution of stoichiometric engines, the highest fuel economy improvements require lean deNOx aftertreatment [LNA] and these, in turn, require new aftertreatment technologies and preferably new fuel specifications. The development of suitable LNA and the cost of implementation of these approaches represents one of the main barriers to improving gasoline engine fuel economy and emissions.
46
Sison, Kelly. "In-cylinder studies of diesel combustion with oxygenated fuels and multiple injections." Thesis, Brunel University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425198.
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47
Durrant, Andrew J. "Model-based control of air/fuel ratio for spark ignition engines." Thesis, University of Nottingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287232.
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48
Ng, Hoon Kiat. "The simulation of combustion in diesel engines using Kiva 3v on a PC platform." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289318.
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49
Clark, Lee A. "Experimental studies and systems modelling to investigate the behaviour of direct injection diesel engines." Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289480.
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50
Abdul, Aziz M. M. "Liquid fuelled jet shear layer gas turbine combustion." Thesis, University of Leeds, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233835.
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