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1
SHOJAEE, Maryam. "Modelling for the thermal degradation of engine oil in diesel engines." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-175385.
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Thermal oil oxidation is an important reason for the engine oil degradation in trucks. Having a comprehensive model that includes all the influential factors while it is feasible for being implemented in the ECUs, was aimed for this work. Therefore, the chemical investigating of the problem leaded to propose a first kinetic model and its thermal analysis caused modelling the oil thermal behaviour. The latter was developed for four compartments: Bearings, turbocharger, piston cooling and oil sump in the oil path through the lubrication system, because the highest oil temperature happens due to friction, combustion of fuels and exhaust gas transportation. Independency from the design parameters of the compartments and simplicity of models for the ECU implementation caused to investigate two various modelling hybrid approach: physical modelling and control theory approach. The first one was done for the bearings and piston cooling, and showed a high level of complexity leading to switch to the second approach. The latter was applied for all compartments while it satisfied requested requirements. To adjust and evaluate the models, an experimental campaign was devoted to acquiring the needed parameters with consideration of the project budget. Also using the previous simulation and experimental efforts at the company provided a possibility to develop flow rate sub-models used in the thermal modelling. The proposed model for all compartments, well predicted the oil thermal behaviour for both stationary and dynamic operating conditions. A comparison between the experimental data for the oil in the oil sump and turbo charger was done to show the reliability of the related models in both stationary and transient statuses. For the bearings, the simulation data for stationary condition were applied as a reference. The modelled oil temperature after piston cooling was compared to a set of experimental data that presented the probable temperature in some conditions close to stationary operating points.
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Sanders, Matthew Graham. "Analytical applications of the peroxyoxalate chemiluminescence reaction." Thesis, University of Plymouth, 1999. http://hdl.handle.net/10026.1/1832.
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The overall objectives of this thesis were to investigate the potential of the peroxyoxalate chemiluminescence (POOL) reaction for the quantitative detection of target analytes in non-aqueous matrices and to compare quantitative performance with fluorescence detection. The target analytes investigated were polycyclic aromatic hydrocarbons (PAHs) and aliphatic amines. These were selected as an important class of compounds in engine exhaust emissions and a detergent additive in diesel fuel respectively. Chapter one outlines the challenges of analysing petroleum products and engine exhaust emissions and discusses the potential of luminescence techniques, particularly chemiluminescence (CL), for the quantification of trace components. The chapter also reviews the technique of flow injection (FT) as a means of sample delivery for CL detection and as a potential technique for field deployment. Liquid chromatography techniques are described as a means of separation of complex matrices, e.g. fuels and engine exhaust particulates, in the laboratory prior to CL detection. The luminescence properties of several PAHs were investigated in Chapter Two. Optimum excitation and emission wavelengths for eleven PAHs in four different solvents were determined using a batch fluorescence technique. A FI approach was used to determine PAH concentrations using fluorescence and POCL detection. Two aryl oxalates; bis(2,4-dinitophenyl)oxalate and bis(2,4,6-trichlorophenyl)oxalate were compared for their suitability for PAH determinations and an investigation of the key variables (e.g. concentration of aryl oxalate and hydrogen peroxide, mobile phase composition and pH) affecting POCL was performed. Recommendations for the optimum conditions for the determination of PAHs by POCL detection were determined, A comparison between a photodiode based detection device and a low power (12V) photomultiplier tube was also described. In Chapter Three the procedure of using POCL detection as a post column liquid chromatography (LC) detector for PAHs has been considered. The performance of the POCL detection system was compared with wavelength programmed fluorescence. Both reversed and normal phase LC was investigated and the suitability of POCL detection with each approach was discussed. Additionally the procedure for the LC separation and analysis of SRM 1649 (Urban Dust/Organics) and SRM 1650 (Diesel Particulate Matter) was described. The relative performance of fluorescence and CL detection are discussed. Chapter four describes the principles of multivariate calibration of spectrophotometric data, and three commonly applied techniques (PCR, PLSI and PLS2). Fluorescence data was obtained for synthetic mixtures of PAHs containing two, three, four and five components. A procedure whereby individual spectra were 'glued' together before undergoing data analysis has been developed and the results obtained discussed. POCL emission spectra for five PAHs were acquired using a two-dimensional charge coupled device (CCD). The sensitivity of the CCD system toward POCL detection of PAHs and a multivariate investigation using benzo[a]pyrene and benzo[k]fluoranthene has been described. The potential of the fluorescence and CL approaches used has been discussed. Chapter five describes the aryl oxalate sulphorhodamine-101 CL reaction and its application to the determination of amines. A FI optimisation of the reaction parameters is presented together with some quantitative data for the detection of a homologous series of amines and dodecylamine (a commonly added detergent compound in diesel fuels). The application of the technique toward the detection of dodecylamine in a diesel fuel matrix and the potential as a field deployable technique was also considered.
3
Ozdemir, Ali. "Experimental Investigation Of Use Of Canola Oil As A Diesel Fuel." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609954/index.pdf.
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In this study, canola oil has been selected for the test on a diesel engine and its
suitability as an alternative fuel has been examined. To decrease the high viscosity of
canola oil, the effect of temperature on viscosity has been researched. Then the fuel
delivery system has been modified to heat canola oil before injecting the oil into the
combustion chamber. Also, ethanol has been tested as an additive by blending with
canola oil. An experimental setup has been installed according to standards to carry
out tests. The set up has been controlled with a computer to take measurements more
precisely and to perform experiment automatically. Experimental investigations
have been conducted on a four cylinder, direct injection diesel engine.
Full load-variable speed tests have been conducted to evaluate engine performance
parameters. In addition 13 mode ESC test cycle has been performed to determine the
exhaust emissions. Engine performance and emissions characteristics of canola oil
and canola-ethanol blend containing 30% ethanol have been compared with those of
baseline diesel fuel. Experimental results show that engine performance decreased
for canola oil. Addition of ethanol into canola oil has been noticed to improve
performance a little with respect to pure canola oil. Although, maximum performance has been obtained with diesel fuel, minimum specifics energy cost is
obtained with canola oil. It has been observed that hydrocarbon (HC) emissions
decrease with canola oil, blending ethanol with canola oil increase HC emissions and
maximum values are read for diesel fuel. Carbon monoxide (CO) emissions have
been observed to be the highest for canola oil but blending ethanol has a decreasing
effect on CO emissions. As for particulate matter (PM), use of canola oil has been
seen to be more pollutant than diesel but adding ethanol in canola reduces PM
emissions significantly.
4
Mirmohammadsadeghi, Mahmoudreza. "Investigation of diesel-ethanol and diesel-gasoline dual fuel combustion in a single cylinder optical diesel engine." Thesis, Brunel University, 2018. http://bura.brunel.ac.uk/handle/2438/17436.
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Ever growing population and increased energy consumption across all industries has resulted in higher atmospheric concentration of the greenhouse gases (GHG) and therefore an increase in the planet's average temperature, which has led to increasingly demanding and more strict legislations on pollutant sources, and more specifically, the automotive industry. As a consequence of all this, the demand for research into alternative energy sources has greatly increased. In this study combustion characteristics, engine performance, and exhaust emission of diesel-ethanol and diesel-gasoline are investigated in an optical direct injection diesel engine. In particular, effects of different substitution ratios and diesel injection strategies are studied when the total fuel energy is kept constant. The three main substitution ratios used in this study include 45% (45% of fuel energy from port-injected ethanol/gasoline and 55% from direct injection diesel), 60%, and 75%. The engine used for this investigation is a Ricardo Hydra single cylinder optical engine running at 1200 rpm. In-cylinder pressure measurement is used for calculating all engine parameters, heat release rate, and efficiency. In addition to the thermodynamic analysis of the combustion parameters, high speed camera was used alongside with a copper vapor laser or the high speed image intensifier in the high speed video imaging for the optical analysis of the effect of the above-mentioned parameters on autoignition and combustion processes, while Horiba particulate analyser and AVL smoke meter were utilized in monitoring and recording emissions for every tested condition. Depending on the testing conditions, such as injection strategy and intake conditions, both dual-fuel operations were able to deliver high efficiency and improved emissions compared to that of a pure diesel engine operation, with the diesel-gasoline operation offering more consistency in improved thermal efficiency, and the diesel-ethanol operation delivering lower emission output. The optical analysis of the combustion represents the main difference in the flame propagation, distribution and quality for each substitute fuel and its substitution percentage, as well as the condition under examination.
5
Norouzi, Shahrouz. "Interaction of diesel type fuels and engine fuel system components in compression ignition engines." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5369/.
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Contact of fuels with engine components at low and elevated temperatures for various amounts of time is found to be challenging as this contact has several effects on engine fuel system components and fuels. Also, storage of fuels for a long period of time is found to have almost the same effect on both engine components and fuels upon engine use. In this thesis fuel and engine components’ contact have been studied for four typical metals used in the construction of many engine fuel systems; in form of pure or alloys (copper, aluminium, mild carbon steel and stainless steel), studied after contact with three of the currently available fuels for use in compression ignition engines. Ultra-low sulphur diesel fuel (ULSD) was used as the fossil fuel, rapeseed methyl ester (RME) as the first generation biofuel and finally gas-to-liquid (GTL) as the second generation of biofuel, obtained via the Fischer-Tropsch process. The investigation was performed in different sections: fuels and metals have been studied for any degradation after contact at low and high temperatures for short and long exposure times, and an understanding of the corrosion process and any degradation on both metals and fuels has been achieved; due to the high hygroscopic character of these fuels and the presence of possible impurities in the fuel, the investigation was extended for analysis of the effect of the presence or absence of absorbed water and dissolved air (in the form of Oxygen) in fuels on degradation and corrosion characteristics of these fuels.
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Duszynski, Marek. "Measurement of lubricant film thickness in reciprocating engines." Thesis, Imperial College London, 1999. http://hdl.handle.net/10044/1/8268.
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Alfieri, Ezio. "Emissions-controlled diesel engine /." Zürich : ETH, 2009. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18214.
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Pang, Hon Hou. "Engine thermal management in light duty diesel engine." Thesis, University of Bath, 2006. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492231.
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This thesis presents the investigation into the potential of improving the performance of Diesel engine through changes in the engine thermal management with the flexibility of integrating the changes from the engine control strategy. Analysis into previous studies in related area has identified low coolant inlet temperature, split cooling system and control of lubricant oil temperature as the features which held such potential. These features are further studied by implementing them on a mass produced Diesel engine in an experimental investigation. Although the engine response on fuel consumption and NOx output for most of the test conditions follow established trends with regard operating temperature, where higher operating temperatures increase NOx output but lowers fuel consumption, there are few unusual responses which can only be accounted by minor change in combustion characteristics. To evaluate the effect of these features, the resulting engine responses from various thermal conditions is compared against those of conventional engine control parameters. It is found that changing the thermal settings can lower the engine fuel consumption much more effectively than changing the settings of engine control parameter but the situation is reversed in the case of NOx output. Further, net improvement offered by the thermal variation is established by integrating the effect of the thermal variation within the flexibility in the fuel injection timing to produce optimised solutions. The optimised solutions indicate that there is a specific set of optimum operating temperature for the cylinder head and engine block every engine speed and load condition. The trend of the required average metal temperature required for optimum engine performance indicate the need for an active controlled engine cooling system in Diesel engine for enhanced performance.
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MANELLI, ANDREA. "Engine Technologies for Reduction of Fuel Consumption and Pollutant Emissions in Light-Duty Diesel Engines." Doctoral thesis, Politecnico di Torino, 2022. http://hdl.handle.net/11583/2971996.
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Bari, Saiful. "Alternative fuels in diesel engine." Thesis, University of Reading, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303788.
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Rezaeian, M. "Modelling of engine transmission systems for heavy vehicles : the differential compound engine versus the turbocharged engine." Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484306.
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Catanese, Alessandro. "Emission characterization and cylinder pressure information for applications in the electronic engine management of diesel engines." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486702.
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In the last few years, diesel engines for passenger cars and light commercial vehicles have achieved in Europe a level of success as never before and, to-· day, several manufacturers are looking at the US market for the close future. This has been possible thanks to the exploitation of turbocharging systems and highly flexible fuel injection equipment which have increased the specific power output of the engine, reducing in the same time the combustion noise and maintaining the high level of fuel efficiency typical of this kind of powertrain. On the other hand the complexity of diesel engines has increased exponentially, with the addition of several sensors and actuators necessary to monitor and control the correct working of the system. In order to achieve the increasing emission targets requested by European and US regulations, it is necessary not only to optimize the calibration of all the engine parameters, but also to ensure that the calibration setpoints are always achieved through an accurate control system. Moreover, it is necessary to be able to estimate how the tolerances errors of the engine sensors and actuators, inevitable in mass production equipment, will affect the robustness of the final engine outputs. In this thesis, experimental investigations have been executed on two different direct injection diesel engines, in order to characterize their emission behaviour and create some general prediction functions for the engine-out emission levels, based on mean value variables. These functions can be easily implemented in power plant engine models, in order to investigate the effect of deviations of single components on the whole engine system. Moreover, an explorative investigation has been carried out on the possible exploitation of in-cylinder pressure data for improving the control of the fuel injection and combustion, achieving an overall engine robustness advantage.
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CASTILLO, MARCANO SERGIO JOSE. "Technological approaches to improve the engine efficiency and to reduce pollutant emissions of automotive diesel engines." Doctoral thesis, Politecnico di Torino, 2014. http://hdl.handle.net/11583/2588574.
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The research work was mainly focused on the technological approach to improve engine efficiency and reduce pollutant emissions applicable to diesel engines which are very often incompatible were assessed through a set of full- scale tests on a real diesel engine in order to satisfy the new emissions limits.
(1) The first strategy evaluated in this work to improve the engine efficiency was the reduction of the mechanical losses: through the incorporation of nanomaterials in the lubricant formulation. The effect of the lubricant oil additivated with MoS2 nanopowders was assessed through a set of full - scale tests on a real diesel engine – several engine points and cooling water temperatures were investigated for both a reference oil and a MoS2-additivated one.
(2) Other strategy to reduce pollutant emissions included in this PhD thesis was the effects of using a 30% by volume blend of a renewable fuel, called Farnesane, and fossil diesel in a small Euro 5 displacement passenger car diesel engine.
(3) And finally, the CeO2/BaO/Pt system was selected in order to perform an NO2-assisted soot oxidation, as a aftertreatment strategy to reduce pollutant emissions. The aim of such catalytic system is to couple the catalytic functionality for soot abatement during DPF regeneration, namely CeO2, and an embedded lean NOx trap (LNT) functionality given by BaO, for NOx storage, whose oxidation over Pt to form adsorbed nitrates is facilitated by the presence of CeO2 itself.
14
Amandus, Nicholas P. "Locomotive emissions effects due to engine configuration." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=3072.
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Thesis (M.S.)--West Virginia University, 2003.Title from document title page. Document formatted into pages; contains xiii, 164 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-87).
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Abdul-Karim, Zainal A. "Direct injection diesel engine combustion diagnostics." Thesis, Loughborough University, 2004. https://dspace.lboro.ac.uk/2134/7681.
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The demand for the protection of the environment from air pollution and reduction of carbon dioxide has resulted in worldwide exhaust emissions regulations imposed on the diesel engines. Fortunately, diesel engine offers the best fuel economy and low emissions of carbon dioxide of most engines currently available. However, the engine's inherent drawbacks are that the engine is heavy, noisy, and expensive, in addition to producing significant level of particulates and nitrogen oxides emissions. The present research attempts to understand the combustion characteristics and emissions trade-off by experimental investigations of the diesel engine using a production Lister Petter 2.97 litres, four-cylinder, high-speed, direct injection diesel engine. The investigation involved the analysis of the in-cylinder pressure data, heat release rate calculation and exhaust gas measurements of various injectors having different nozzle geometry. The engine experiments cover both the investigation of the fuel injection and the engine operating parameters such as injection rate, nozzle geometry, the engine load and speed. The effects of each parameter on ignition delay, heat release rate, nitrogen oxides emissions, smoke density, and total hydrocarbon levels were investigated. Two complementary diagnostic techniques were employed in order to assist in understanding the injection characteristics. The first technique involved the imaging of the fuel sprays from the different injectors in a constant volume spray chamber using a CCD camera. The images were than process using a dedicated image processing software. The second technique involved the measurements of the fuel injection rates from the injectors using the Bosch Tube meter. A three-zone model was developed to determine the heat release rate of combustion. The cylinder pressure data was used to validate the model written in Matlab computer programme. The model is based on the principles of the First Law of Thermodynamics applied to the three zones, formed due to the fuel injection into the combustion chamber. The heat release rate profiles produced by the model were used to analyse the formation of pollutants that were measured in the exhaust gas. The results showed that injectors with large nozzle hole diameters produced high smoke levels, especially at high engine load conditions with small increase in NOx. These injectors also caused the sprays to impinged on the combustion chamber walls at high load conditions. On the other hand, injectors having small nozzle hole diameters produced high levels of NOx while the smoke emission levels were low. The effect of nozzle geometry has little significant on the emissions of THC.
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Blom, Cornelius Janse. "Diesel engine performance using oxygenated fuels." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/97075.
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Thesis (MSc)--Stellenbosch University, 2015.ENGLISH ABSTRACT: With worldwide emissions standards becoming more stringent over the last decade, the South African market seems set to follow suit. Older technology engines are however unable to attain these stringent standards and will require cleaner burning fuels. Biofuels like biodiesel and bioethanol-diesel blends are an attractive option as a result of their inherently oxygenated nature and renewable, low carbon footprint. Oxygenated fuels have been found to lower particulate and soot emissions without any significant increase in NOx, thus alleviating the usual particulate-NOx trade-off. In this study an existing diesel engine test facility has been upgraded to include emission equipment, and a low cost pressure indicating system. Fuel-to-fuel comparative testing was done with pump diesel and splash blended fuels consisting of pump diesel blended with varying amounts of ethanol and also biodiesel without including any cetane enhancing or blend stability additives. Emission analysis of the blended fuels showed a marked reduction in soot emission with little to no increase in NOx emission for all oxygenated fuels. This type of soot reduction without NOx increase is difficult to obtain through any other method. Blend stability was however a problem with the 15% ethanol-diesel blends.
AFRIKAANSE OPSOMMING: Met wêreldwye uitlaatgas standaarde wat al hoe strenger geword het oor die laaste dekade, lyk dit asof dit net ‘n kwessie van tyd is voor Suid-Afrika dieselfde roete volg. Ouer tegnologie binnebrandenjins kan egter nie hierdie streng standaarde handhaaf nie en sal dus vereis dat die brandstof skoner brand. Biobrandstowwe, soos biodiesel en bio-etanol-diesel mengsels, blyk ‘n aantreklike opsie te wees vanweë hul natuurlike inhoud van suurstof en as hernubare hulpbron. Wanneer suurstof houdende brandstowwe soos hierdie verbrand word, word daar gevind dat daar ‘n daadwerklike afname in rook uitlaat is sonder enige merkbare toename in NOx uitlaatgasse. Dit is teenstrydig met die gewoonlike wisselwerking wat daar tussen hierdie twee uitlaatgas produkte is. In hierdie studie word die bestaande diesel enjin toetssel opgegradeer om uitlaatgas analiese toerusting asook ‘n lae-koste silinderdruk meettoestel te bevat. Brandstof-tot-brandstof vergelykings toetse word gedoen met gewone diesel asook toets diesel wat gemengde konsentrasies biodiesel of bio-etanol bevat. Die toets diesel bevat egter geen aanvullings om mengselstabiliteit of cetaan te verbeter nie. Toetsresultate toon dat daar merkbare vermindering in rook uitlaat is met min tot geen toename in NOx. Hierdie tipe van resultaat met produkte van ontbranding is moeilik om op enige ander manier te bewerkstellig. Daar word ook gevind dat diesel met 15 % bio-etanol nie ‘n stabiele mengsel is nie en dat fase skeiding plaasvind.
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Bottone, Francesco. "Les-CMC for diesel engine combustion." Thesis, Imperial College London, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529364.
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Dowell, John P. "Thermal Cracks in Diesel Engine Crankshafts." Case Western Reserve University School of Graduate Studies / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=case1093747466.
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Wojdas, Olga. "Numerical simulations for diesel engine development." Lyon, INSA, 2010. http://theses.insa-lyon.fr/publication/2010ISAL0039/these.pdf.
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Considering the increasingly rigorous pollutions regulations, the reduction or even the elimination of nitrogen oxide (NOx) and soot emissions occuring in Diesel engines, are inevitable. In order to reach that goal, more and more sophisticated technologies are under development leading to very complex physical behavior of injected spray. Facing the lack of the models describing such phenomena, the thesis focuses on the understanding of the existing models performance and their efficiency assessment. We try to understand the physical phenomena and the constraints of the classical models to be able to employ them in the most skillful way. The main result of the present research is the methodology suggestion for the numerical studies of Diesel engine, with the principal point concerning the boundary condition of injection velocity, whose various assumptions lead to the very important results dispersion. The objective of this methodology is to help the researchers of the applied engineering to understand the most important phenomena appearing in Diesel engine, and to indicate some points to succeed the numerical simulations using the classical models of the jet breakupL'évolution des normes anti-pollution de plus en plus restrictives rend inéluctable la réduction voire l'élimination des émissions d'oxydes d'azote (Nox) et de suies générées par les moteurs diesel. Les technologies de plus en plus poussées développées pour atteindre ces objectifs mènent néanmoins à des phénomènes physiques très complexes dans la chambre de combustion. Face au manque actuel de modèles physiques décrivant de tels comportements, la thèse se concentre sur la compréhension et l'évaluation des modèles existants. Les phénomènes physiques pris en compte par chaque modèle ainsi que leur limitations sont étudiés afin d'en faire un usage le plus pertinent possible. Le résultat principal du travail présenté est une proposition de méthodologie de simulation numérique pour les moteurs diesel, avec en particulier l'adaptation de la condition limite en vitesse d'injection menant à une grande dispersion des résultats. Le but de la méthodologie est de fournir à la recherche appliquée une compréhension des phénomènes les plus importants présents dans un moteur diesel et de donner des pistes pour une simulation numérique robuste avec les modèles classiques de fragmentation du jet
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Houdyschell, David. "A diesel two-stroke linear engine." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1312.
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Thesis (M.S.)--West Virginia University, 2000.Title from document title page. Document formatted into pages; contains ix, 64 p. : ill. (some col.) Includes abstract. Includes bibliographical references (p. 42-43).
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Crua, Cyril. "Combustion processes in a diesel engine." Thesis, University of Brighton, 2002. https://research.brighton.ac.uk/en/studentTheses/d0d73428-8bf3-460f-8297-f40572fd4bd7.
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The effects of in-cylinder and injection pressures on the formation and autoignition of diesel sprays at realistic automotive in-cylinder conditions was investigated. A two-stroke diesel Proteus engine has been modified to allow optical access for visualisation of in-cylinder combustion processes. Various optical techniques were used to investigate the combustion processes. These include high-speed video recording of the liquid phase, high-speed schlieren video recording of the vapour phase and laser-induced incandescence for soot imaging. The spray cone angle and penetration with time data extracted from photographic and high-speed video studies are presented. The effects of droplet evaporation, breakup and air entrainment at the initial stage of spray penetration were studied theoretically using three models. It was found that the predictions of the model combining bag breakup and air entrainment are in good agreement with the experimental measurements. Spray autoignition was investigated using video, in-cylinder pressure, and schlieren recordings. Pseudo three-dimensional visualisation of the autoignition was achieved by simultaneous use of two high-speed video cameras at right angles to each other. The effects of elevated injection and in-cylinder pressures on the ignition delay and ignition sites have been investigated. Laser-induced incandescence was performed to obtain maps of soot concentration for a range of engine conditions. The influence of in-cylinder and injection pressures on soot formation sites and relative soot concentration has been studied. The work has been mainly focused on the specificities of soot formation under extreme in-cylinder conditions.
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Wijetunge, Roshan. "Transient optimisation of a diesel engine." Thesis, University of Bath, 2001. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341697.
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Hernandes, Marcelo Rocha. "Estudo dos componentes auxiliares de partida a frio de motores movidos a Diesel." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264377.
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Orientador: Sergio Santos MühlenDissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
Made available in DSpace on 2018-08-18T19:10:57Z (GMT). No. of bitstreams: 1 Hernandes_MarceloRocha_M.pdf: 3294457 bytes, checksum: d5c6210ad1c775f02c1a394d65ab908c (MD5) Previous issue date: 2011
Resumo: A questão da partida a frio de motores movidos a Diesel ainda é um problema que não foi apropriadamente resolvido e se torna particularmente crítico em face da tendência de redução de níveis de emissões de poluentes a baixas temperaturas e da taxa de compressão do motor visando redução do consumo de combustível. Embora esteja claro que existem alguns fatores-chave que levam a um apropriado processo de partida a frio, sua relevância e relações não são claramente compreendidas. Assim, os esforços para a otimização do processo de partida a frio são principalmente baseados em procedimentos de tentativa e erro em câmaras climáticas a baixas temperaturas, com sérias limitações em termos de confiabilidade da medição em algumas condições, baixa repetibilidade e altos custos com experimentos. O objetivo deste trabalho é estudar os componentes auxiliares de partida a frio dos motores a Diesel com o intuito de adquirir conhecimento sobre este tema para aplicação em propulsores, de maneira que estes possam ser utilizados em regiões com temperaturas negativas com desempenho confiável. Os componentes estudados serão apresentados, bem como sua aplicação e importância na tarefa de proporcionar as condições adequadas à partida a frio do motor. Além disso, uma visão geral será dada em relação à contribuição que estes componentes trazem na redução de emissões de poluentes e consumo de combustível
Abstract: Cold start in Diesel engines is a problem which has not yet been properly solved and becomes particularly critical with the current trend to reduce the emission levels at low temperatures and engine compression ratio addressed to fuel consumption decrease. Although it is clear that there are some key factors whose control leads to a proper cold start process, their individual relevance and relations are not clearly understood. Thereby, the efforts on optimization of the cold start process are mainly based on a trial-and-error procedure in climatic chambers at low ambient temperature, with serious limitations in terms of measurement reliability, low repeatability and high experiments costs. The objective of this work is to study cold start auxiliary components of Diesel engines in order to acquire knowledge on this topic for application in engines in a way that they can be used in regions with low temperatures with reliable performance. The components studied will be presented, as well as its application and importance of providing appropriate conditions to engine cold start. In addition, an overview will be given on the contribution that these components are going to bring in the reduction of emissions and fuel consumption
Mestrado
Eletrônica
Mestre em Engenharia Automobilistica
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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.
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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).
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Wallace, Scott J. "Diesel Engine Energy Balance Study Operating on Diesel and Biodiesel Fuels." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1212586902.
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Canfield, C. Alan. "Effects of diesel-water emulsion combustion on diesel engine NOx emissions." [Florida] : State University System of Florida, 1999. http://etd.fcla.edu/etd/uf/1999/amg2169/canfield%5Fc.pdf.
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Thesis (M.S.)--University of Florida, 1999.Title from first page of PDF file. "X" in "NOx" in title is subscript. Document formatted into pages; contains vii, 85 p.; also includes graphics. Vita. Includes bibliographical references (p. 79-84).
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Westlund, Anders. "Measuring and Predicting Transient Diesel Engine Emissions." Licentiate thesis, KTH, Machine Design (Div.), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10202.
Full textAbstract:
Due to its impact on human health and the nature surrounding us, diesel engine emissions have been significantly reduced over the last two decades. This reduction has been enforced by the legislating organs around the world that gradually have made the manufacturers transform their engines to today’s complex high-tech products. One of the most challenging areas to meet the legislations is transient operation where the inertia in gas-exchange system makes transition from one load to another problematic.
Modern engines have great potential to minimize the problems associated with transient operation. However, their complexity also imposes a great challenge regarding optimization and systematical testing of transient control strategies in an engine test bed could be both expensive and time consuming.
The objective of this project is to facilitate optimization of transient control strategies. This should be done by identifying appropriate measurement methods for evaluation of transients and by providing models that can be used to optimize strategies off-line.
Measurement methods for evaluation of transients have been tested in several experiments, mainly focusing on emission but also regarding e.g. EGR flow. Applicable instruments for transient emission measurements have been identified and used. However, no method to measure soot emissions cycle resolved has yet been found. Other measurements such as EGR flow and temperatures are believed to have significantly decreased accuracy during transients.
A model for prediction of NOx emissions have been used and complemented with a new approach for soot emission predictions that has been developed in this project. The emission models have been shown to be applicable over a wide range of operating conditions with exception for highly premixed combustion. It has also been shown that models developed for steady state conditions can be used for transients operation.
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Al-Khalidi, Ghazi. "Bore polishing of diesel engine cylinder liners." Thesis, Brunel University, 1987. http://bura.brunel.ac.uk/handle/2438/6615.
Full textAbstract:
There are two important omissions in the literature on bore polishing, firstly there is no evidence of the successful development of a reliable tribo test device to simulate bore polishing and secondly, the mechanism of bore polishing has not been fully defined. The aims of this study were: 1. To establish the principal characteristics of bore polishing In engines. 2. To produce bore polishing in the laboratory. 3. Differentiate between two reference oils in a laboratory tribo test. 4. To understand the mechanism of bore polishing. The principal characteristics of bore polishing have been identified by the examination of Tornado cylinder bores from an engine test. The graphite structure is visible on the surface which has a surface finish of less then 0.125 micro-m in C.L.A. value. The components used in these tests were a grey cast iron piston ring running on a grey cast iron cylinder bore typically used in commercial engines. A reciprocating tribo test was used to distinguish between the two reference oils. The result showed higher friction, wear and a smoother surface with the oil causing bore polishing compared to the other oil which did not produce bore polishing. Adding carbon, taken from the wall of a piston used in an engine test, to the lubricant in the laboratory tribo test produced a phenomenon resembling bore polishing. Comparisons have been made between the tribo test results and service engines and a good correlation has been obtained. Several analytical techniques have been used and the knowledge of bore polishing has been advanced. In particular, it is suggested that a combination of two processes, one mechanical and the other chemical, are associated with bore polishing. Four wear mechanisms were identified during this investigation; abrasion, delamination, corrosion and adhesion.
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Welch, S. "Computational modelling of diesel engine smoke emission." Thesis, Cranfield University, 1995. http://dspace.lib.cranfield.ac.uk/handle/1826/4611.
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This thesis is addressed to the problem of predicting the emission of exhaust smoke
from the diesel engine. A simulation program based on a zonal phenomenological
combustion model has been developed, permitting analysis of soot modelling
techniques. For the first time, a comparative study of the common soot model
expressions has been undertaken. Model sensitivities and behaviour have been
critically assessed in order to determine the key model parameters and to establish
a more solid predictive capability. Validation of both the combustion and soot
predictions was made by means of comparison with the extensive experimental
data-set of Kamimoto.
The combustion model results showed a very good match between -predicted and
experimental heat release curves. The only notable weakness derived from the
method chosen to represent the effect of air swirl on the jet. Otherwise, the
combustion predictions were deemed to be sufficiently accurate to serve as an
effective platform for soot model development and analysis.
The predictions of exhaust smoke for different operating conditions revealed the
importance of accurately describing the overall air-to-fuel ratio in the spray. The
effect of load variation was poorly represented due to neglect of the transfer of
combustion products between the model zones.
Soot rate predictions were generally quantitatively poor, thus requiring expression
calibration. The comparative study of soot expressions identified a ranking of
sensitivities of the formation expressions. Though oxidation is conceptually simpler,
more distinct qualitative differences were observed in the behaviour of the
expressions. The predictions of exhaust soot were found to be highly sensitive to
the 'matching' of the formation and oxidation expressions over the period of the
combustion process, and with poorly matched expressions, a very high sensitivity
to the soot model constants was shown. The best results were obtained by use of
simple quasi-chemical rate expressions.
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Brace, Chris. "Transient modelling of DI TCi diesel engine." Thesis, University of Bath, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362260.
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Ye, Shifei. "Oxidation catalyst studies on a diesel engine." Thesis, University of Bath, 2010. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533408.
Full textAbstract:
In this thesis, the experimental test facilities consisted of a well instrumented live Ford 2.0 litre turbocharged diesel engine connected to a specially made exhaust can, which contained a diesel oxidation catalyst (DOC). Experiments were performed on DOCs, which were specially prepared by Johnson Matthey, and had thermocouples mounted in their walls to measure axial temperature profiles. These DOCs consisted of a Pt catalyst dispersed in an alumina washcoat on a cordierite monolith supports, and were representative of a commercial application. Experiments were performed on Full-scale DOCs (o.d. = 106 mm, length = 114 mm), and also on Thin-slice DOCs (length = 5 and 10 mm), which generate some interesting data, and enabled a technique that is normally only used in laboratory bench-top experiments to be applied to a live engine. A number of different methodologies were developed based on (a) the operation of the engine at pseudo-steady-state operating conditions, and (b) transient experiments (e.g. a pulse of CO was injected into the exhaust gas just before the DOC). For example, it was shown how experiments on a live engine can be used to explore: (a) the hysteresis between light-off and extinction curves, (b) how catalyst temperature rise during warm-up of a DOC, (c) the promotion effect that hydrogen has on the conversion of CO, (d) the extent of competition for active catalytic sites, e.g. between CO, THCs, propane or hydrogen. The main findings are: (a) the hysteresis between light-off and extinction curves are mainly caused by CO inhibition, (b) the promotion effect of hydrogen on CO oxidation is largely attributed to thermal effect, (c) LHHW form rate expression is not adequate for catalytic converter modelling under transient conditions, (d) the competition for active catalytic sites is not apparent at the test conditions performed in this thesis. Moreover, a number of case studies were also used to illustrate how the experimental results/techniques developed in this thesis, may be used to support modelling studies. iii
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Zhang, Kai. "Air charge system emulation for diesel engine." Thesis, University of Bath, 2010. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.521014.
Full textAbstract:
The work presented in this thesis details a novel engine evaluation approach utilising real-time simulation and advanced engine testing systems for general applicability to new generations of air charging systems. A novel engine air charging system including a charge air handling unit (CAHU) has been developed which is connected to an engine to emulate advanced boosting system conditions. Significant analytical and development work has focused on generating a real-time turbocharger model such that the CAHU can be effectively controlled to emulate the turbocharger performance under both steady and pulsating conditions. Experimental work was carried out to evaluate this new engine air charge testing system against a production turbocharged baseline engine. The accuracies with respect to the boost pressure, turbocharger speed, mass air flow, and fuel consumption in the steady state tests are above 95%, and the level of confidence for the engine back pressure is approximately 90%. The difference of turbocharger speed between the steady turbocharger model and the pulsation model is also identified. In engine transient tests, the boost pressure and engine torque have shown fast response characteristics similar to that of the baseline engine. While general transient trends were achieved, some issues were identified with the high speed control of the CAHU interacting with the dSPACE real time turbocharger model. It is proposed that future improvement can be achieved via applying new control algorithms to improve the accuracy and tracking the CAHU control without increasing the system instabilities.
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Felsch, Christian. "Combustion modeling for diesel engine control design." Aachen Shaker, 2009. http://d-nb.info/997696826/04.
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Bates, Michael C. "Parametric design of diesel engine inlet ports." Thesis, University of Brighton, 2004. https://research.brighton.ac.uk/en/studentTheses/6551124d-62d5-483b-a684-d02116f32059.
Full textAbstract:
Inlet port flow characteristics are critical in determining the overall performance of diesel combustion systems. The relationship between inlet port geometry and performance has long been a subject of interest to many researchers, although as yet a comprehensive understanding remains elusive. The ongoing need to provide advanced powertrain design solutions in order to meet increasingly stringent emissions legislation, whilst meeting customer expectations and minimising engineering costs, has driven the development of new approaches to engine design. In particular, the fundamental advantages of multivalve technology, coupled with rapidly improving fuel delivery systems has placed new requirements on inlet port performance characteristics. Statistical methods and knowledge-based design are emerging as potentially powerful tools in this field of research, supported by rapid developments in computing power.
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Shamail, Shafay. "Distributed memory diesel engine simulation using transputers." Thesis, University of Bath, 1990. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278254.
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Acar, Joseph 1977. "Effect of engine operating parameters and fuel characteristics on diesel engine emissions." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/30319.
Full textAbstract:
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.Includes bibliographical references (leaf 32).
To examine the effects of using synthetic Fischer-Tropsch (FT) diesel fuel in a modern compression ignition engine, experiments were conducted on a MY 2002 Cummins 5.9 L diesel engine outfitted with high pressure, common rail fuel injection, a variable geometry turbo charger, cooled EGR and a fully configurable engine management computer. Additionally, the effect of varied injection timing and EGR rates were studied to examine how the engine can be optimized for FT fuel. The test fuels included two standard diesel fuels, one with 400 PPM sulfur content and the other 15 PPM sulfur. The experimental fuels were Syntroleum Corporation's S-1 fuel, as well as blends of 25% S-1 with a balance of 15 or 400 PPM D2. Tests were conducted with three engine operating conditions: 1682 RPM, 474 kPa BMEP; 2011 RPM, 1000 kPa BMEP; 2011 RPM, 1400 kPa BMEP. It was found that FT fuel reduced NOx emissions 19% in low load tests, but alone had little effect in higher load tests. FT fuel reduced particulate matter (PM) emissions in almost all test case, on the order of 25 to 75%. Retarding injection timing and increasing EGR both reduce NOx emissions. In the case of standard fuels, these reduction come at the expense of increased PM. However, FT fuel reduced this effect and allows for more retarded timing and further increased EGR rates to control NO. Blended fuels, containing 25% FT, by volume, and a balance of 15 PPM or 400 PPM fuel, were found to provide most of the benefit of straight FT fuel. The FT/15 blend reduced PM 40% and the FT/400 blend reduced PM 60%.
by Joseph Acar.
S.M.
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Haysom, F. J. "Enhanced performance simulation of diesel engines." Thesis, University of Bath, 1989. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236456.
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Reifarth, Simon. "EGR-Systems for Diesel Engines." Licentiate thesis, KTH, Machine Design (Div.), 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12205.
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Nwafor, Onwuzurigbo Martin I. "Alternative fuels in diesel engines." Thesis, University of Reading, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239031.
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Barr, William Gerald. "Low heat rejection diesel engines." Thesis, University of Nottingham, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.254429.
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Moore, David John. "Condition monitoring of diesel engines." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/condition-monitoring-of-diesel-engines(629ec6ef-d54b-449a-90c1-32ac0eee8bcf).html.
Full textAbstract:
Reliability of emergency Diesel generator systems, or indeed any Diesel engines in a wide range of fields is critical. Traditional maintenance procedures for these engines follow time based or statistical based methods. Due to the wide variety of uses of Diesel engines it is not possible for these forms of maintenance to be as effective as condition based monitoring. Condition based monitoring holds many advantages over traditional maintenance methods. It allows for the earlier detection and diagnosis of a fault and allows for planned maintenance work avoiding costly and unexpected downtime. It also reduces the overall maintenance costs as parts need only be replaced when they are worn or faulty, not based on a time schedule. The ability to unobtrusively monitor the engines also has many advantages in- cluding reduced sensor cost and negating the need to tamper permanently with the engine. Acoustic monitoring has been identified as the most prominent and effective way in which to achieve this goal. As such, extensive experimentation was carried out on both large and small Diesel engines over a wide range of speeds, loads and faults and the data was then analysed. The data was first investigated statistically and then processed using Independent Component Analysis after the statistical re- sults were found to be poor. A program was written for the automatic comparison of the collected data and the results presented in this thesis show that ICA and acoustic emissions have the ability to aid in engine fault detection and diagnosis. The results have shown to be reliable, consistent and able to distinguish when the engine is healthy or faulty.
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Lindström, Mikael. "Methods for Characterization of the Diesel Combustion and Emission Formation Processes." Doctoral thesis, KTH, Maskinkonstruktion (Avd.), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-34140.
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In this thesis various aspects of the diesel engine fuel injection, combustion and emission formation processes have been evaluated. Several types of evaluation tools and methods have been applied. Fuel spray momentum was used to characterize injection rate and hole-to-hole variations in fuel injectors. Using both instantaneous fuel impulse rates and instantaneous mass flow measurements, spray velocity and nozzle flow parameters were evaluated. Several other hole-to-hole resolved injector characterization methods were used to characterize a set of fuel injectors subjected to long term testing. Fuel injector nozzle hole-to-hole variations were found to have a large influence on engine efficiency and emissions. The degree of hole-to-hole variations for an injector has been shown to correlate well with the performance deterioration of that injector. The formation and atomization of fuel sprays, ignition onset and the development of diffusion flames were studied using an optical engine. Flame temperature evaluations have been made using two different methods. NO-formation depends strongly on flame temperature. By applying a NO-formation evaluation method based on both heat release rate and flame and gas temperature it was possible to achieve a reasonable degree of correlation with measured exhaust emissions for very varying operating conditions. The prediction capability of the NO-formation evaluation method was utilized to evaluate spatially and temporally resolved NO-formation from flame temperature distributions. This made it possible to pinpoint areas with a high degree of NO-formation. It was found that small hot zones in the flames can be responsible for a large part of the total amount of NO that is produced, especially in combustion cases where no EGR is used to lower the flame temperature. By applying optical diagnostics methods the combustion and emission formation phenomena encountered during production engine transients were evaluated. The transient strategy of the engine involved reducing the EGR-rate to zero during the initial parts of the transient. Increased general flame temperature and the occurrence of small hot zones were found to explain the increase in NO-emissions during these transients.QC 20110530
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Darabi, Ahmad. "Dynamic transient modelling of a diesel generating set." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269101.
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Asay, Rich. "A Five-Zone Model for Direct Injection Diesel Combustion." BYU ScholarsArchive, 2003. https://scholarsarchive.byu.edu/etd/100.
Full textAbstract:
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.
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Aivaz, Balian Razmik. "The effect of compression ratio on the performance of a direct injection diesel engine." Thesis, Brunel University, 1990. http://bura.brunel.ac.uk/handle/2438/11249.
Full textAbstract:
This thesis considers the effect of compression ratio on the performance of a direct injection diesel engine. One aspect of engine performance is considered in great detail, namely the combustion performance at increased clearance volume. This aspect was of particular interest because variable compression ratio (VCR) systems normally operate by varying the clearance volume. The investigation relied upon results obtained both from experimental and computer simulating models. The experimental tests were carried out using a single-cylinder direct-injection diesel engine, under simulated turbocharged conditions at a reduced compression ratio. A number of one-dimensional computer models were developed; these simulate the induction and compression strokes, and the fuel spray trajectories in the presence of air swirl. The major objectives of the investigation were: to assess the benefits of VCR in terms of improvements in output power and fuel economy; to assess the effects on combustion of increased clearance volume, and investigate methods for ameliorating resulting problems; develop computational models which could aid understanding of the combustion process under varying clearance volume conditions. It was concluded that at the reduced compression ratio of 12.9:1 (compared to the standard value of 17.4:1 for the naturally-aspirated engine), brake mean effective pressure (BMEP) could be increased by more than 50%, and the brake specific fuel consumption (BSFC) could be reduced by more than 20%. These improvements were achieved without the maximum cylinder pressure or engine temperatures exceeding the highest values for the standard engine. Combustion performance deteriorated markedly, but certain modifications to the injection system proved successful in ameliorating the problems. These included: increase in the number of injector nozzle holes from 3 to 4, increase in injection rate by about 28%, advancing injection timing by about 6°CA. In addition, operation with weaker air fuel ratio, in the range of 30 to 40:1 reduced smoke emissions and improved BSFC. Use of intercooling under VCR conditions provided only modest gains in performance. The NO emission was found to be insensitive to engine operating conditions (fixed compression ratio of 12.9:1), as long as the peak cylinder pressure was maintained constant. Engine test results were used in order to assess the accuracy of four published correlations for predicting ignition delay. The best prediction of ignition delay with these correlations deviated by up to 50% from the measured values. The computer simulation models provided useful insights into the fuel distribution within the engine cylinder. It also became possible to quantify the interaction between the swirling air and the fuel sprays, using two parameters: the crosswind and impingement velocities of the fuel spray when it impinges on the piston-bowl walls. Tentative trends were identified which showed that high crosswind velocity coincided with lower smoke emissions and lower BSFC.
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Tornehed, Petter. "Particulate Emissions Associated with Diesel Engine Oil Consumption." Doctoral thesis, KTH, Maskinelement, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-25880.
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Particulate emissions from diesel engines have been a key issue for diesel engine developers in recent decades. Their work has succeeded in reducing the exhaust particles from the combustion of fuel, which has led to increasing interest in the contribution of particulates from lubrication oil. When discussing oil-related particulate emissions, hydrocarbon particles are customarily referred to. This thesis uses a broader definition, in which oil-related particulate emissions are modelled not only by the hydrocarbons, but also include the ash, carbons, and sulphate oil particulate emissions. The model developed in the project uses input data as oil consumption and oil ash content combined with tuning parameters, such as the oil ash transfer rate (ash emissions divided by oil consumption and oil ash content). Controlled engine tests have been performed to verify assumptions and fill knowledge gaps. The model can be applied to a variety of diesel engines, although the tuning factors might have to be reset. For example, introducing diesel particulate filters would dramatically reduce the oil ash emissions, since oil ash would accumulate in the filter. Oil consumption has played a central role in the present research. The modelling results indicate that special attention should be paid to oil consumption under running conditions with a low in-cylinder temperature, since the oil survival rate is high there. Under low-load and motoring conditions, hydrocarbons proved to be the main contributor to oil-related particulate emissions. At high engine load, oil ash emissions were the largest contributor to oil-related particulate emissions.QC 20101103
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Lewis, Clive, and Henrik Dembinski. "Miller-cycle on a heavy duty diesel engine." Thesis, KTH, Maskinkonstruktion (Inst.), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99473.
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Denna report beskriver ett examensarbete inom ämnet förbränningsmotorteknik och är utfört på Scania CV AB i Södertälje i sammarbete med Kungliga Tekniska Högskolan i Stockholm. Fordonsindustrin står inför nya utmaningar när en större fokusering på koldioxid (CO 2) utsläpp från väg-gående fordon efterfrågas, vilket är direkt kopplat till fordonets bränsleförbrukning. Detta skall klaras av med lägre övriga emissioner i form av kväveoxider (NOx) och rök som är de två stora problemområdena för en dieselmotor. Scania vill därför undersöka potentialen med Miller cykling och om detta koncept skulle kunna implementeras på en lågeffektsmotor. Idén är att byta hög effekt mot verkningsgrad på motorer i motorprogrammet som inte utnyttjar hela grundmotorns effektpotential. Med Miller cykling menas senare- eller tidigarelagd stängning av insugsventilen och på så sätt öka graden expansionsarbete i förhållande till kompressionsarbete, dvs. öka den indikerade verkningsgraden. Då detta medför en minskning i effektiv slagvolym då cylindern inte fylls med luft helt måste kompensering i laddtryck göras för att motorn skall få samma luftmängd. En del kompressionsarbete görs då alltså utanför cylindern som belastar turbosystemet och inte motorn. En ny turbomatchning måste således göras då förflyttningar i turbomappen görs på ett mindre fördelaktigt sätt. Arbetet inleddes med motorprov av en encylindrig dieselmotor som har samma cylinder, kolv och cylinderhuvud som en D12 produktionsmotor där förbränningsdata samlades in för senare simuleringar i GT-power. Två olika kompressioner, tidig resp. sen stängning av insugsventil och EGR provades i testcellen. Det visade sig att generellt sjunker NO x-emissionerna vid Millring tillsammans med en högre verkningsgrad på framförallt höglast. Vid jämförelse mellan standardkompression 17.3:1 CR standard ventilprofil och 23:1 CR Millerprofil åstadkoms en ökning (i procentenheter) av bromsad verkningsgrad på mellan 1.79 % till 3.3 % vid encylinderprov utan EGR. Den annorlunda kolvgropen vid 23:1 CR ökar rök-emissionerna, kolvgropsutformning bör alltså optimeras för att sänka röken. Med EGR är den maximala ökningen i bromsad verkningsgrad (också i procentenheter) mellan 0.93 % och 3.43 %. Vid låglast ökar avgastemperaturen med upp till 100°C vid 50 kW effektuttag på en motsvarande DLC motor vid 1250 rpm. Detta är till fördel vid eventuell avgasefterbehandling. Vid fullmotorsimuleringar med matchad turbo ökar den bromsade verkningsgraden från 43.5 % (standard motor 17.3:1 CR) till 45.2 % (Miller motor 23:1 CR) på bästa punkten i ESC cykeln. Miller tillsammans med höjd kompression kan vara ett koncept som är användbart i vissa effektvarianter i en motorfamilj där en högre avgastemperatur på låglast och en högre verkningsgrad på höglast efterfrågas. Det som bör undersökas närmare är att få ned rök emissionerna vid en ökning i kompression.The Miller cycle is defined as earlier or later closing of the intake valves which increases the effective expansion ratio in relation to the compression. This means that the indicated engine efficiency should be increased. The earlier or later closing of the inlet valves means that the effective swept volume is reduced and must therefore be compensated by increasing the intake pressure with a turbo to make sure the same air mass is found in the cylinder when compression takes place. This is in effect an outsourcing of work from the cylinder to the turbo. This outsourcing will place greater demands on the turbo system, a result which means that a new turbo must be matched to the engine. The work commenced with testing of a single cylinder diesel engine which had the same cylinder, piston and head as a production engine (in effect 1/6 of a Scania 6 cylinder lorry engine). The results of the tests were then used to calibrate simulation models made in GT-power. Two different compression ratios, early and late closing of the inlet valves and with / without EGR were tested in the engine test cell. It was found that generally NO xlevels were reduced and engine efficiency increased especially for the higher load points. A comparison between the standard engine with 17.3:1 CR standard valve lift profile and a CR of 23:1 together with a Miller cycle gave an increase of between 1.9 and 3.3 % (percent units) in brake efficiency when the single cylinder test engine was run without EGR. It is worth mentioning that the bowl of the 23:1 CR piston was not optimized for smoke emissions, more work needs to be carried out in this area at a later date. With the use of EGR it was possible to increase the brake efficiency by between 0.93 and 3.43 %. When the engine was run at low load (1250 rpm and 50kW for a full engine) the exhaust temperature rose by up to 100 °C. This would lead to benefits in the after treatment of exhaust gases. A simulation model of a full engine was calibrated and run in GT-power. Results showed that the best brake efficiency for a standard full engine when taken through the ESC cycle was 43.5 %. This could be increased to 45.2 % by increasing the compression ratio to 23:1 and using a Miller cycle. The summary of the report concludes that a combination of increased compression ratio and running the engine with a Miller cycle is a viable concept for some of the engines in Scanias engine program. The benefits include a higher exhaust temperature under low loads and increase in brake efficiency for higher loads. Further work needs to be carried out on the optimization of the piston geometry with the aim of reducing smoke for the higher compression ratios.
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Ozbakir, Erol. "Development of aluminum alloys for diesel-engine applications." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32568.
Full textAbstract:
Weight reduction in vehicles has important benefits of fuel economy and reduction in greenhouse gas emissions as well as improved vehicle performance. The current material for the diesel-engine block/head is mostly ductile iron and replacing it with aluminum alloys would result in very effective weight reduction (30-40%). Current commercial cast aluminum alloys, however, soften at engine operating temperatures exceeding 200°C and would cause early fracture in the diesel engine. Two new alloys derived from the commercial alloy (A356) are described in terms of microstructure, creep, aging behavior and tensile properties at elevated temperatures. The alloy containing both peritectic (Cr, Zr and Mn) and age hardenable elements (Cu and Mg) shows superior aging response at 200°C (for 200 hours) and creep properties at 300°C (for 300 hours). Interestingly, the alloy has better tensile strength (161MPa) at 250°C with adequate ductility compared to the current engine alloys, A356 and A356+Cu. The improvement in mechanical properties is attributed to the newly formed thermally stable fine precipitates (ε-AlZrSi, α-AlCrMnFeSi…) inside the α-Al dendrites.La diminution du poids des véhicules résulte dans l'apport important de bénéfices au niveau de l'économie d'essence, la réduction des gaz à effets de serre aussi bien que l'amélioration du rendement du véhicule. Le matériau principal présentement utilisé pour la fabrication de la tête et du bloc moteur est la fonte ductile. Le remplacement de la fonte par des alliages d'aluminium va conduire vèrs une diminution (30-40%) significative du poids. Les alliages d'aluminium de coulée actuels laissent voir dans le temps un ramolissement du métal lorsque les températures d'opération du moteur exèdent 200ºC. Ce phénomène provoquera à plus ou moins brève échéance un bris prématuré du moteur diésel. Deux nouveaux alliages développés à partir de l'alliage commercial A356 sont présentés dans les termes suivants : microstructure, fluage, comportement au vieillissement et propriétés de traction à des températures élevées. L'alliage contenant les deux groupes d'éléments soit péritectiques (Cr, Zr et Mn) dans un premier temps et pour le durcissement structural par le vieillissement (Cu et Mg) dans un second temps, démontre une réponse supérieure au vieillissement à la température de 200ºC pour une période de 200 heures et de meilleures propriétés de fluage à la température de 300ºC pour une période de 300 heures. De façon plus intéressant, l'alliage possède de meilleures propriétés de traction (161MPa) à 250ºC avec une ductilité adéquate comparativement aux alliages de bloc moteur fabriqués à partir des alliages A356 et A356 + Cu. L'amélioration des propriétés mécaniques est ainsi attribuable aux nouveaux précipit
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Manuvelpillai, Joël Umakanthan. "Adsorption of aromatics with diesel engine derived soot." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.495643.
Full textAbstract:
The diesel engine combustion process produces carbonaceous deposits known as soot. Such carbonaceous deposits are accumulated at critical locations in a diesel engine, with detrimental effect on engine performance. The main objective of this project is to explore the role of polymers and additives, on the stability of carbon black, soot model, in organic solvents. Lubrizol uses a wide range of polyolefin derivatives, such as polar head groups grafted onto saturated polymers, as lubricants in diesel engine oil. A new generation of additive, known as a Dispersant Viscosity Modifier, that has dual functional properties in a single molecule, has been synthesised. The additive can be used for both dispersancy and viscosity modification. It is composed of a long hydrocarbon chain and a polar head group.
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Arco, Sola Javier. "Hydraulic Characterization of Diesel Engine Single-Hole Injectors." Thesis, KTH, Maskinkonstruktion (Inst.), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-170810.
Full textAbstract:
Due to world trend on the emission regulations and greater demand of fuel economy,the research on advanced diesel injector designs is a key factor for the next generation diesel engines. For that reason, it is well established that understanding the effects of the nozzle geometry on the spray development, fuel-air mixing, combustion and pollutants formation is of crucial importance to achieve these goals.In the present research, the influence of the injector nozzle geometry on the internalflow characteristics is studied. For this purpose, ten single-hole diesel injectors differingin the orifices degree of conicity (five cylindrical, five conical) but with similar nozzleflow capacity have been characterized geometrically (measurements of nozzle outletsection) and hydraulically. The mass flow and momentum flux rates have been measured for a wide range of experimental conditions. Special attention is given to study the cavitation phenomenon since the cylindrically-shaped nozzle orifices areexpected to propitiate cavitation due to abrupt changes in flow direction. The study hasbeen carried out with two different fuels: n-Dodecane and commercial diesel, therebythe effect of the fuel properties is also analyzed.The results show that the measured nozzle outlet diameters are higher than the nominalspecification for both nozzle types. As expected, the onset on cavitation on thecylindrical nozzles has been identified causing a reduction on the injected mass for all tested conditions. The effective diameter for the cylindrical nozzles have been found tobe around 180 μm (geometrical diameter ~212 μm) and around 190 μm (geometrical diameter ~191 μm) for the conical ones. Finally, the higher density of Diesel with respect to n-Dodecane have resulted on mass flow rates around 8% over the n-Dodecanevalues for the same test conditions.