Dissertations / Theses on the topic 'Fuel injection systems'

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.

The fuel pressure is one of the central control variables of a modern common-rail injection system. It influences the generation of nitrous oxide and particulate matter emissions, the brake specific fuel consumption of the engine and the power consumption of the fuel pump. Accurate control of the fuel pressure and reliable diagnostics of the fuel system are therefore crucial components of the engine management system. In order to develop for example control or diagnostics algorithms and aid in the understanding of how hardware changes affect the system, a simulation model of the system is desirable.  A Simulink model of the XPI (Xtra high Pressure Injection) system developed by Scania and Cummins is developed. Unlike the previous models of the system available, the new model is geared towards fast simulations by modelling only the mean flow and pressure characteristics of the system, instead of the momentary flow and pressure variations as the engine rotates. The model is built using a modular approach where each module represents a physical component of the system. The modules themselves are based to a large extent on the physical properties of the components involved, making the model of the system adaptable to different hardware configurations whilst also being easy to understand and modify.
Bränsletrycket är en av de centrala styrvariablerna i ett modernt common-rail insprutningssystem. Det påverkar utsläppen av kväveoxider och partiklar, motorns specifika bränsleförbrukning och bränslepumpens effektförbrukning. Nogrann reglering och tillförlitliga diagnoser av bränslesystemet är därför mycket viktiga funktioner i motorstyrsystemet. Som ett hjälpmedel vid utveckling av dessa algoritmer samt för att öka förståelsen för hur hårdvaruförändringar påverkar systemet är det önskvärt med en simuleringsmodel av bränslesystemet.  En Simulink modell av XPI (Xtra high Pressure Injection) systemet som utvecklats av Scania och Cummins har utvecklats. Till skillnad från de redan tillgängliga modellerna av systemet fokuserar denna modell på snabba simuleringsförlopp genom att enbart modellera medeltryck och medelflöden istället för de momentana trycken och flödena i systemet när motorn roterar. Modellen är uppbyggd av moduler som var och en representerar en fysisk komponent i systemet. Modulerna är mestadels uppbyggda kring de fysikaliska egenskaperna hos komponenten de försöker modellera vilket gör modellen av systemet anpassningsbar till olika hårdvarukonfigurationer och samtidigt lätt att förstå.

The first part of this work focuses on control experiments performed on an unstable kerosene-fueled turbulent combustor. Using a phase shift controller and primary fuel modulation stability is successfully gained for a wide band of global equivalence ratios allowing the limitations of the control scheme to be characterized. It is shown that control signal saturation can significantly impact the ability of the control scheme to stabilize the system. Three different regions of controllability are defined based on the degree of saturation. A hysteresis behavior is also found to exist for the controller settings depending on whether stability is being maintained or realized for an unstable system.

The second part of this work focuses on the impact that primary fuel modulation has on the fuel spray. Measurements for a simplex nozzle and an air-assist nozzle are taken under both static and dynamic operating conditions with a Phase Doppler Anemometry system. The dynamic modulation is found to significantly impact the spray properties of both nozzles.
Master of Science

This thesis was initiated by the need to develop a stable low vibration engine with a high power to weight ratio. A new rotary (Wankel) engine was chosen to meet these requirements. A further operating criterion was that the engine was required to use JP8 (aviation fuel). The difficulty created by the use of JP8 is that its combustion temperature is higher than other conventional fuels, and preheating is necessary, especially in the case of cold start. Thus, the question posed was, could a more appropriate and efficient method of fuel delivery be devised? This thesis presents the design and construction of a fluid spray visualisation system for investigating the macroscopic and microscopic characteristics of fuel sprays using low injection pressure up to 10 bar (1 MPa). Laser imaging techniques have been used for data acquisition. The thesis has been divided into several aspects. Firstly, a background study of fluid sprays and fuel injection strategies was carried out. This has centred on the relationship between droplet size and the combustion process. It further investigated what differentiated the fuel delivery approach to Wankle from that to other engines. Secondly, two families of fuel injector were tested and evaluated within the optical engineering laboratory using deionised water (DI) water for safety reasons. The first family involved conventional gasoline injectors with several nozzle arrangements. The second family involved medical nebulisers with several nozzle diameters. The evaluation of the fuel injectors required developing a fluid delivery circuit, and a specific ECU (Electronic Control Unit) for controlling pulse delivery and imaging instrument. The company associated with the project then set up a test cell for performing experiments on JP8 fuel. The initial global visualisation of the jet spray was made using a conventional digital camera. This gave a measurement of the spray angle and penetration length. However, as the study moved to the more precise determination of the fuel spray particulate size, a specialised Nd:YAG laser based diagnostic was created combined with a long range diffraction limited microscope. Microscopic characterisation of the fuel sprays was carried out using a backlight shadowgraph method. The microscopic shadowgraphy method was applied successfully to resolve droplets larger than 4 microns in diameter. The spray development process during an individual fuel injection cycle was investigated, presenting the frequency response effect of electronic fuel injectors (EFI) on the spray characteristics when operating at high injection frequencies (0.25 -­‐ 3.3 kHz). The velocity distribution during the different stages of an injection cycle was investigated using PIV. The influence of the injection pressure on the spray pattern and droplet size was also presented. Novel fluid atomisation systems were investigated for the capability of generating an optimum particulate distribution under low pressure. Finally, it was found that a new electronic medical nebuliser (micro-­‐dispenser) could be used to deliver the fuel supply with the relevant particle size distribution at low flow rate and high injection frequency. However, as yet it has not been possible to apply this approach to the engine; it is hoped that it will yield a more efficient method of cold starting the engine. The characteristics of this atomiser can be applied to provide a controllable fuel supply approach for all rotary engines to improve their fuel efficiency. The second part of this research discusses the droplets-­‐light interaction using Mie scattering for fluid droplets smaller than the microscope visualisation limit (4 microns). Mie scattering theory was implemented into Three-­‐Components Particle Image Velocimetry (3C-­‐ PIV) tests to address a number of problems associated with flow seeding using oil smoke. Mie curves were used to generate the scattering profile of the oil sub-­‐micron droplets, and therefore the scattering efficiency can be calculated at different angles of observation. The results were used in jet flow PIV system for the determination of the optimum position of the two cameras to generate balanced brightness between the images pairs. The brightness balance between images is important for improving the correlation quality in the PIV calculations. The scattering efficiency and the correlation quality were investigated for different seeding materials and using different interrogation window sizes.

In recent years, serious restrictions on diesel emission levels, combined with price instability and a significant increase in imports, has forced researchers to look for alternatives to this fossil fuel. Biodiesel is widely accepted as an alternative because it can be used in diesel engines without any substantial modifications and produced by sustainable resources. However, there are serious gaps in available knowledge regarding the effects of biodiesel blends on engine fuel injection systems and the engine combustion process. Therefore, this research focuses on the investigation into such effects through a vibration analysis of fuel injection systems in order to achieve nonintrusive quantitative diagnosis and hence condition monitoring of CI engines. Having identified the specifics of technique gaps by a comprehensive literature study, this research firstly, investigates the dynamics of the fuel injection system with a CI engine running on biodiesel blends as fuels. This is achieved by numerical modelling analysis and experimental studies, which paves ways for using vibration response of fuel injection to diagnose the dynamic behaviour of different fuel properties. Then it investigates the of the change dynamic behaviour of fuel injection on engine combustion process. Finally, it explores the diagnostics of engine valve train clearance faults with an engine running with biodiesel and biodiesel blends based on engine fuel injection vibration responses. A mathematical model has been developed and used to simulate the behaviour of the fuel injection system, including the fuel delivery and injector needle valve motions. It has concluded that the high pressure dynamic forces within the injection system will be affected by fuel properties such as fuel density, viscosity and bulk modules. The simulation results demonstrated; (i) that, the injector pressure is higher than that of the fuel injection pump, whose amplitudes are about 10% higher for biodiesels compared with petro-diesel; (ii) the levels of the pressure forces applied to the delivery valve and injector needle valve are also higher for biodiesel blends and (iii) nearly 1° (cam shaft) advance in the times of fuel injection rates and valve impacts with biodiesel and biodiesel blends. These predictions are confirmed by experimental results obtained by injection line pressures and pump vibrations and in-cylinder pressures. Diesel engines are particularly prone to the engine combustion process primarily due to a fault in the fuel injection system and an abnormal clearance valve train conditions. The high-signal to noise ratio pump vibrations obtained from the pump body can be easily used for detecting and diagnosing faults from fuel injections. In the meantime, the research has also established that the pump vibration signals can be also used to recognise valve train diagnostics with medium effort of signal processing. It has found that the vibration levels become higher, due to the faults as a consequence of additional fuel supply to compromise the loss of overall power caused by poor combustion performance on the cylinder with an increased valve clearance. Moreover, B20 and B40 exhibit the similar changes with that of petro-diesel in the proposed high frequency envelop amplitudes (HFEA) whereas B100 shows less increased values. However, the pressure measurements are not very clear in representing these small changes in valve clearances for both the exhaust and inlet valves. Compared with head vibration signals, which also can indicate the faults by a reduced level of vibration due to an effect combined reduced valve movement stroke with gas flow dampening, the pump vibration signals uniformly show the injection events and allow combustion uniformity between different cylinders to be diagnosed using a single transducer, whereas it may produce less accurate diagnosis by the head vibrations because of the close overlap of combustion and valve impact responses which needs complicated methods to be separated.

Resumen Los sistemas de inyección directa han sido uno de los principales puntos focales de la investigación en motores, particularmente en sistemas Diésel, donde la geometría interna, movimiento de aguja y comportamiento del flujo afectan el spray externo y por tanto determinan completamente el proceso de combustión dentro del motor. Debido a regulaciones medioambientales y al potencial de los (más ineficientes) motores "Otto", grandes esfuerzos se están aportando en investigación sobre sistemas de inyección directa de gasolina. Los motores GDi tienen el potencial de incrementar sustancialmente la economía de combustible y cumplir con las regulaciones de gases contaminantes y de efecto invernadero, aunque aún existen muchos desafíos por delante. Esta tesis estudia en detalle una moderna tobera GDi que fue específicamente diseñada para el grupo de investigación conocido como Engine Combustion Network (ECN). Con metodologías punteras, este inyector ha sido usado en un amplio abanico de instalaciones experimentales para caracterizar el flujo interno y varias características clave de geometría y funcionamiento, y aplicarlo para evaluar cómo se relaciona con los efectos observados del comportamiento del chorro externo. Para la caracterización interna del flujo, el objetivo ha sido determinar la geometría de la tobera y el desplazamiento de aguja, caracterizar la tasa de inyección y el flujo de cantidad de movimiento, y evaluar el flujo cercano. Algunas metodologías nunca antes habían sido empleadas en inyectores GDi, y muchas otras lo han sido solo eventualmente. Para la geometría interna, el levantamiento de aguja y el flujo cercano, varias técnicas avanzadas con rayos-x fueron aplicadas en las instalaciones de Argonne National Laboratory. Para la tasa de inyección y flujo de cantidad de movimiento, las técnicas disponibles en el departamento han sido adaptadas desde Diésel y aplicadas en inyectores GDi multiorificio. Dado lo novedoso de las técnicas aplicadas, las particularidades de las metodologías han sido discutidas en detalle en el documento. Aún con la elevada turbulencia del flujo interno, el inyector se comporta de forma consistente inyección a inyección, incluso cuando el estudio se centra en la variabilidad orificio a orificio. Esto ha sido atribuido al comportamiento repetitivo de la aguja, evaluado en los experimentos. También fue observado que el flujo estabilizado tiene una variación de alta frecuencia que no pude ser explicado por el movimiento de la aguja, sino por el particular diseño de las toberas. El análisis de geometría interna realizado a ocho toberas nominalmente iguales resultó en la obtención de un punto vista único en la construcción de toberas y la variabilidad de dimensiones clave. Las medidas de tasa de inyección permitieron estudiar la respuesta hidráulica del inyector a varias variables como la presión de inyección, presión de descarga, temperatura de combustible y la duración de la señal de comando. Estas medidas fueron combinadas con medidas de flujo de cantidad de movimiento para estudiar el bajo valor del coeficiente de descarga, el cual fue atribuido al bajo levantamiento de aguja y coeficiente L/D de los orificios. Por otro lado, el estudio del spray externo resultó en la identificación de un importante fenómeno específico a este particular hardware, el colapso del spray. Las extensivas campañas experimentales, utilizando Schlieren e iluminación trasera difusa (DBI) permitieron identificar y describir las características macroscópicas del spray y las condiciones bajo las que el colapso ocurre. El colapso del spray se forma por una combinación de interacción de las diferentes plumas (causado por el flujo interno) y determinadas condiciones ambiente que promueven evaporación y entrada de aire. Fue determinado que a niveles de densidad y temperatura moderados se desarrolla el colapso, modificando completamente el comportamiento espera
Abstract Fuel injection systems have been one of the main focal points of engine research, particularly in Diesel engines, where the internal geometry, needle lift and flow behavior are known to affect the external spray an in turn completely determine the combustion process inside engines. Because of environmental regulation and the potential development of the more inefficient Otto engines, a lot of research efforts are currently focused into gasoline direct injection systems. GDi engines have the potential to greatly increase fuel economy and comply with pollutant and greenhouse gases emissions limits, although many challenges still remain. The current thesis studies in detail a modern type of GDi nozzle that was specifically developed for the international research group known as the Engine Combustion Network (ECN). With the objective of employing state-of-the-art techniques, this hardware has been used in a wide range of experimental facilities in order to characterize the internal flow and several geometrical and constructive aspects like needle lift; and assess how it relates to the effects seen external spray. For the internal flow characterization, the goal was to determine the nozzle geometry and needle displacement, to characterize the rate of injection and rate of momentum, and evaluate the near-nozzle flow. Some methodologies applied here have never been applied to a GDi injector before, and many have only been applied rarely. For the internal geometry, needle lift and near-nozzle flow, several advanced x-rays techniques were used at Argonne National Laboratory. For the rate of injection and rate of momentum measurements, the techniques available in CMT-Motores Térmicos have been adapted from Diesel spray research and brought to multi-hole GDi injectors. Given the novelty of the techniques used, the particular methodologies and setups are discussed in detail. Despite the high turbulence of the flow, it was seen that the injector behaves consistently injection to injection, even when studying variation in individual holes. This is attributed to the repetitive behavior of the needle that was observed in the experiments. It was also observed that the stabilized flow has a high frequency variability that could not be explained by random movement of the needle, but rather by the particular design of the nozzle. The geometrical analysis done to eight, nominally equal nozzles, allowed a unique view into the construction of the nozzle and provided insights about the variability of key dimensions. The rate of injection measurements allowed to study the hydraulic response of the injector to the main variables like rail pressure, discharge pressure, fuel temperature and command signal duration. These measurements were combined with the rate of momentum measurements to study the low value of the discharge coefficient, that ultimately was attributed to the low needle lift and low L/D ratio of the orifices. On the other hand, the study of the external spray yielded the identification of very important phenomena specific to this particular hardware, the spray collapse. The extensive experimental campaigns featuring shadowgraph (Schlieren) and Diffused Back Illumination (DBI) visualization techniques allowed identifying and describing the macroscopic characteristics of the spray and the conditions under which the collapse occurs. The spray collapse engenders from a combination of the internal flow that creates plume interaction, and ambient conditions that promote air entrainment and evaporation. At moderate density and temperature levels the collapse develops, completely modifying the expected trends in the behavior of the plumes.
Resum Els sistemes d'injecció directa han sigut un dels principals punts focals de la investigació en motors, particularment en sistemes dièsel, en què la geometria interna, el moviment de l'agulla i el comportament del flux afecten l'esprai extern i per tant determinen completament el procés de combustió dins del motor. Degut a regulacions mediambientals i al potencial dels (més ineficients) motors "Otto", grans esforços s'estan aportant en investigació sobre sistemes d'injecció directa de gasolina. Els motors GDi tenen el potencial d'incrementar substancialment l'economia del combustible i complir les regulacions de gasos contaminants i d'efecte hivernacle, encara que existeixen molts desafiaments per davant. Esta tesi estudia en detall una moderna tovera GDi que va ser especialment dissenyada per al grup d'investigació conegut com a ECN. Amb l'objectiu de desenvolupar metodologies punteres, este injector ha sigut usat en un ampli ventall d'instal·lacions experimentals per tal de caracteritzar el flux intern i diverses característiques clau de la seua geometria i funcionament, per tal d'avaluar com es relacionen amb els efectes observats del comportament de l'esprai extern. Per a la caracterització interna del flux, l'objectiu ha sigut determinar la geometria de la tovera i el desplaçament de l'agulla, caracteritzar la taxa d'injecció i el flux de quantitat de moviment, i avaluar el flux proper. Algunes metodologies no s'havien empleat abans en injectors GDi, i moltes altres ho han sigut únicament de manera eventual. Per a la geometria interna, l'alçament de l'agulla i el flux proper, s'han aplicat diverses tècniques avançades amb raigsx a les instal·lacions d'Argonne National Laboratory. Per a la taxa d'injecció i el flux de quantitat de moviment, les tècniques disponibles al departament han sigut adaptades des de Dièsel i aplicades a injectors GDi multi-orifici. Considerant la novetat de les tècniques aplicades, les particularitats de les metodologies es discuteixen en detall al document. A pesar de l'elevada turbulència del flux intern, l'injector es comporta de manera consistent injecció a injecció, inclús quan l'estudi se centra en la variabilitat orifici a orifici. Aquest fet s'ha atribuït al comportament repetitiu de l'agulla, avaluat als experiments. També es va observar que el flux estabilitzat té una variació d'altra freqüència que no pot ser explicat pel moviment de l'agulla, sinó pel particular disseny de les toveres. L'anàlisi de la geometria interna realitzat a vuit toveres nominalment iguals va permetre obtenir un punt de vista únic en la construcció de toveres i la variabilitat de dimensions clau. Les mesures de taxa d'injecció van permetre estudiar la resposta hidràulica de l'injector a diverses variables com la pressió d'injecció, la pressió de descàrrega, la temperatura del combustible i la duració de la senyal de comandament. Estes mesures van ser combinades amb mesures de flux de quantitat de moviment per tal d'estudiar el baix valor del coeficient de descàrrega, el qual va ser atribuït al baix alçament de l'agulla i al coeficient L/D dels orificis. D'altra banda, l'estudi de l'esprai extern va permetre identificar un important fenomen específic d'aquest hardware particular: el col·lapse de l'esprai. Les extensives campanyes experimentals, utilitzant Schlieren i il·luminació darrera difusa (DBI) van permetre identificar i descriure les característiques macroscòpiques de l'esprai i les condicions sota les quals el col·lapse té lloc. El col·lapse de l'esprai es forma per una combinació d'interacció de les diverses plomes (causat pel flux intern) i determinades condicions ambient que promouen evaporació i entrada d'aire. Es va determinar a quins nivells de densitat i temperatura moderats es desenvolupa el col·lapse, modificant completament el comportament esperat de l'esprai.
Vaquerizo Sánchez, D. (2018). Study on Advanced Spray-Guided Gasoline Direct Injection Systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/99568
TESIS

O sistema de gerenciamento dos motores automotivos tem se tornado um avançado sistema de controle. Seu objetivo é fazer com que o nível de emissões de gases poluentes gerados esteja dentro dos padrões exigidos pela legislação de cada país e ao mesmo tempo manter os níveis de desempenho e dirigibilidade. Apresenta as principais características de um típico sistema de gerenciamento de motores a combustão interna, descreve os modos de controle e aponta tendências futuras. Descreve o sistema de controle desenvolvido, o qual servirá de ferramenta de pesquisa para trabalhos que envolvam o estudo de técnicas de controle aplicadas neste contexto e pesquisas envolvendo otimização do rendimento dos motores automotivos
The automotive engine management system has become an advanced control system. Its objective is to maintain the pollutants gas emissions according to legislations and to maintain the performance and driveability, at the same time. It presents the main features of a tipical internal combustion engine management system, it describes the control modes and it point out the future tendencies. It describes the control system developed, which one will be usefull as a tool for research involving control applied in this context and engine automotive efficiency optimization researchs

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: This thesis comprises of the testing and evaluation of a modern diesel engine running on both biodiesel and mineral diesel on the upgraded Bio-fuels Testing Facility (BTF) at Stellenbosch University. The project was motivated by the need to install a modern diesel engine onto the existing BTF test rig for biodiesel testing. In this project, the BTF was re-designed to support a new Volkswagen 1.9L TDI engine. The capabilities of the BTF were then expanded further by the implementation of a low-cost pressure indicating system, utilising an optical pressure transducer. During the testing of biodiesel, it was found that the calorific value of the biodiesel was 14% lower than that of the tested mineral diesel. The ignition quality (cetane index) of the biodiesel was also lower than that of the mineral diesel. Even so, the engine only experienced a maximum power loss of 4.2%. During heat-release analysis, it was determined that there was no significant difference in the combustion process of biodiesel and that of mineral diesel. The conclusion could be made that biodiesel is suitable for use in modern TDI engines. Testing validated the operation of the upgraded test cell, and in trials it was determined that the test results are highly repeatable. The pressure indicating set proved to have some limitations. Only simplified heat-release analyses and reasonable indicated power calculations could be performed with the indicating set. Recommendations were made for improvement in future research.
Centre for Renewable and Sustainable Energy Studies

Orientador: Rogério Gonçalves dos Santos
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A motivação em se estudar os fenômenos que acontecem em cada subsistema de um motor de combustão interna ciclo Otto reside na possibilidade de se prever e otimizar seu funcionamento, em especial com os diferentes combustíveis de nova geração que estão sendo inseridos no mercado. O processo de atomização que ocorre nos bicos injetores de combustível, dispositivos integrantes do sistema de injeção eletrônica do motor, apresenta forte relação com a posterior reação de combustão e, por conseguinte, com a eficiência térmica do motor. No presente trabalho, experimentos foram conduzidos para investigar o efeito da temperatura do líquido em parâmetros de atomização de um atomizador do tipo mecânico-centrífugo utilizado em bicos injetores de combustível automotivos. O aparato experimental consistiu de uma bancada de injeção de combustível conectada a um sistema de controle de calor, este com objetivo de variar a temperatura do combustível. Os parâmetros de atomização foram avaliados por meio da técnica de Shadowgraphy, a fim de se medir diâmetro de gotas, distribuição de partículas e campo de velocidades. Gasolina e etanol em diferentes temperaturas foram usados para fornecer variação nas propriedades do líquido, ambos com a mesma pressão de injeção. Os resultados de tamanho de gota foram dados, principalmente, em termos de Sauter Mean Diameter (SMD) e outros diâmetros representativos que se mostraram pertinentes. Todas as medições foram realizadas em duas diferentes distâncias axiais do orifício de descarga. Para as duas distâncias escolhidas, 25 mm e 100 mm, o SMD e a velocidade se mostraram insensíveis à faixa de temperatura testada, devido à baixa variação das propriedades dos combustíveis. Por outro lado, a distribuição das partículas permitiu visualizar o efeito da temperatura nos diâmetros das gotas, mostrando que o aumento da temperatura proporciona diminuição no tamanho das gotas, e o comparativo entre os parâmetros nas duas distâncias axiais permitiu visualizar o efeito da primeira e segunda atomização sobre o spray
Abstract: The motivation in studying the phenomena that happen in each internal combustion engine subsystem lies in the possibility to predict and optimize its operation. The atomization process that occurs in fuel injectors, devices that belong to engine injection system, has a strong relation with the subsequent combustion reaction and thus with the engine thermal efficiency. Experiments were performed to investigate the liquid temperature effect on atomization parameters in an internal combustion engine pressure-swirl atomizer. The experimental apparatus consisted of a flow control rig connected with a heat control system. The flow rig, which is an injection system, was built specifically for that purpose and the heat system goal was to vary the liquid temperature. The atomization parameters were evaluated by means of Shadowgraphy technique in order to measure drop mean diameter, particle size distribution and drop velocity field. Gasoline and ethanol in different temperatures were used to provide variation in liquid properties and the same injection pressure was used for both fuels. The results for drop sizing were expressed in terms of Sauter Mean Diameter (SMD) and the velocity field as well as the particle size distribution measurements were taken in two different axial distances from the nozzle exit. At both distances, 25 mm and 100 mm, SMD and velocity seemed to be insensitive to the range of temperature used because it provided low variation in fuel properties. On the other hand, particle size distribution allowed the visualization of temperature effect on drop diameters, showing that increasing temperatures decrease droplet sizes, and the comparison between two axial distances allowed seeing the effects of first and second atomization on the spray
Mestrado
Termica e Fluidos
Mestra em Engenharia Mecânica

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.

This last decade experienced a sudden increase of interest in the control of thermo-acoustic instabilities, in particular through the use of fuel modulation techniques. The primary goal of this research was to design, construct and characterize a high bandwidth proportional fuel injection system, which could be used to study the effect of specific levels of fuel modulation on the combustion process and the reduction of thermo-acoustic instabilities. A fuel injection system, incorporating the use of a closed loop piston and check valve, was designed to modulate the primary fuel supply of an atmospheric liquid-fueled swirl stabilized combustor operating at a mean volumetric fuel flow rate of 0.4 GPH. The ability of the fuel injection system to modulate the fuel was examined by measuring the fuel line pressure and the flow rate produced during operation. The authority of this modulation over the combustion process was investigated by examining the effect of fuel modulation on the combustor pressure and the heat release of the flame. Sinusoidal operation of the fuel injection system demonstrated: a bandwidth greater that 800 Hz, significant open loop authority (averaging 12 dB) with regards to the combustor pressure, significant open loop authority (averaging 33 dB) with regards to the unsteady heat release rate and an approximate 8 dB reduction of the combustor pressure oscillation present at 100 Hz, using a phase shift controller. It is possible to scale the closed loop piston and check valve configuration used to create the fuel injection system discussed in this work to realistic combustor operating conditions for further active combustion control studies.
Master of Science

Includes abstract.
This study set out to investigate the effects of diesel fuel properties on the behaviour of a common rail fuel injection system, with particular emphasis on the injection rate shape characteristics. The investigation included the design and commissioning of experimental equipment for the measurement of fuel properties at typical common rail pressures, as well as the measurement of instantaneous fuel flow rate by a modified Bosch Indicator method. Data was then collected for two different diesel fuels, operating in two different fuel injector designs. The two fuels were EN590 (a European reference fuel) and GTL (a fuel derived from natural gas). The two injectors were a Bosch solenoid type injector, and a Bosch piezo type injector.

HCCI combustion engines can provide high fuel efficiencies with low NOx emissions compared to SI and CI engines due to their lean combustion, high compression ratios and low combustion temperatures. The disadvantage of HCCI is that it is inherently difficult to control. The need for an optimized fuel injection system is crucial in the design of an HCCI engine to achieve desirable and controllable performance. The aim of this thesis was to develop and optimize the fuel injection system for a 2- stroke, opposed piston gasoline engine thus continuing the development of the engine towards achieving stable HCCI combustion. The engine and the components that make up the fuel supply and injection system characteristics were analyzed using experimental and theoretical methods. The mathematical ideal mass of fuel and point of injection was found (when exhaust ports are closed). Injector delay, mass vs. electrical on-time and voltage sensitivity was found. Deflector designs used to divert the fuel flow laterally along the cylinder were studied and prototypes manufactured and tested. The engine was then run with new settings and deflector and the results analyzed. It was found that an L-cut design gave the best spray properties in this situation. An Lcut design with two internal seals gave the most favorable spray angle and atomization. A mass equation was formed that linked the mass injected to on-time in the ECU with consideration of the varying supply voltage. Using this mass equation and taking into account the delay, an ideal injection point was found. Implementing the new deflector and with improved injection timing, the engine was able to run smoothly with the theoretical mass required for λ=1 at 6000rpm and produce 0.28 kW of power. This was a noticeable improvement over previous engine tests which required more fuel mass for stable combustion. In conclusion, information was gained which allowed improvement of the injection timing and fuel control. The engine was run with much more accurate masses of fuel injected and injection times. The deflector improved atomization and optimized the spray angle. The data gained from the tests and analysis can be implemented into the engines ECU code for automated injection timing and fuel mass. This, coupled with the improved spray profile has aided in the continuing development of the engine towards stable, efficient HCCI combustion.
HCCI förbränningsmotorer kan ge hög verkningsgrad med låga NOx-utsläpp jämfört med SI och CI-motorer på grund av sin magra förbränning, högt kompressionsförhållande och låg förbränningstemperatur. Nackdelen med HCCI är att den är svår att kontrollera. Behovet av ett optimerat bränsleinsprutningssystem är avgörande för utformningen av en HCCI motor för att uppnå önskvärt och kontrollerbart resultat. Syftet med detta examensarbete var att utveckla och optimera bränsleinsprutningssystemet för en 2-takts, motkolvs bensinmotor och därmed fortsätta utvecklingen av motorn för att uppnå en stabil HCCI förbränning. Motorn och de komponenter som utgör bränsletillförseln analyserades med hjälp av experimentella och teoretiska metoder. Den matematiska ideala massan bränsle och den ideala insprutningsvinkeln bestämdes (när både insugs-och avgas portarna var stängda). Insprutningsfördröjning kontra ”electrical on-time” och spänningskänslighet bestämdes. Olika utformningar av deflektorn som används för att avleda bränsleflödet i sidled längs cylindern studerades, prototyper tillverkas och testades. Motorn kördes därefter med nya inställningar och ny deflektor och resultaten analyserades. Det visade sig att ”L-cut ”designen gav de bästa spray egenskaperna i denna situation. En ”L-cut” design med två inre tätningar gav den mest fördelaktiga sprayvinkeln och finfördelningen. En massekvation skapades som länkade den insprutade massan till ”elektrical on-time” i ECUn med hänsyn till den varierande matningsspänningen. Genom att använda massekvationen och samtidigt ta hänsyn till fördröjningen kunde en ideal insprutningsvinkel hittas. Implementering av den nya deflektorn tillsammans med förbättrad insprutningsvinkel gjorde att motorn kunde köras jämnt med den teoretiska massan som krävs för λ = 1 vid 6000rpm, och samtidigt producera effekt om 0,28 kW. Det var en märkbar förbättring jämfört med tidigare motortester som krävde dubbla bränslemängden för stabil förbränning. Sammanfattningsvis erhölls data som gjorde förbättringarna av insprutningsvinkel och bränslekontrollen möjlig. Motorn kördes med mycket mer exakt insprutad bränslemassa och insprutningsvinkel. Deflektorn förbättrade finfördelningen och optimerade sprayvinkeln. De data som insamlas från tester och analyser kan implementeras i motorns ECU kod för automatiserad insprutningstidpunkt och bränsle massa. Detta har tillsammans med den förbättrade sprayprofilen bidragit till den fortsatta utvecklingen av motorn mot en stabil, effektiv HCCI förbränning.

Thesis (M.S.)--University of Missouri--Rolla, 2007.
Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 29, 2007) Includes bibliographical references (p. 153-155).

High-bandwidth fuel modulation is currently one of the most promising methods for active combustion control. To attenuate the large pressure oscillations in the combustion chamber, the fuel is pulsed so that the heat release rate fluctuations damp the pressure oscillations in the combustor. This thesis focuses on the development and implementation of a high-bandwidth, proportional modulation system for liquid-fuel active combustion control. The throttle valve modulation system, discussed in this thesis, uses a 500-um piezoelectric stack coupled with an off-the-shelf valve. After comparing three other types of actuators, the piezoelectric stack was selected because of its compact size, bandwidth capabilities, and relatively low cost. Using the acoustic resonance of the fuel line, the system is able to achieve 128% pressure modulation, relative to the mean pressure, and is capable of producing more than 75% flow modulation at 115 Hz. Additionally, at 760 Hz the system produces 40% pressure modulation and 21% flow modulation with flow rates between 0.4 and 10 gph. Control authority was demonstrated on a single-nozzle kerosene combustor which exhibits a well-pronounced instability at ~115 Hz. Using the modulation system, the fundamental peak of the combustion instability was reduced by 30 dB, and the broadband sound pressure levels inside the combustor were reduced by 12 dB. However, the most important conclusion from the combustion control experiments was not the system?s accomplishments, but rather its inability to control the combustor at high global equivalence ratios. Our work indicates that having the ability to modulate a large percentage of the primary fuel is not always sufficient for active combustion control.
Master of Science

The predictive design of fuel injection hardware used for active combustion control is not well established in the gas turbine industry. The primary reason for this is that the underlying mechanisms governing the flow rate authority downstream of the nozzle are not well understood. A detailed investigation of two liquid fuel flow modulation configurations is performed in this thesis: a piston and a throttle-valve configuration. The two systems were successfully built with piezoelectric actuation to drive the prime movers proportionally up to 800 Hz.

Discussed in this thesis are the important constituents of the fuel injection systemthat affect heat release authority: the method of fuel modulation, uncoupled dynamics of several components, and the compressibility of air trapped in the fuel line. Additionally, a novel technique to model these systems by way of one-dimensional, linear transmission line acoustic models was developed to successfully characterize the principle of operation of the two systems. Through these models, insight was gained on the modes through which modulation authority was dissipated and on methods through which successful amplitude scaling would be possible. At high amplitudes, it was found that the models were able to successfully predict the actual performance reasonably well for the piston device.

A proportional phase shifting controller was used to test the authority on a 40-kW rig with natural longitudinal modes. Results show that, under limited operating conditions, the sound pressure level at the limit cycle frequency was reduced by about 26 dB and the broadband energy was reduced by 23 dB. Attenuation of the fuel pulse at several combustor settings was due to fluctuating vorticity and temporal droplet distribution effects.
Master of Science

This master thesis treats the modelling of a common-rail direct fuel injection system where pressure generation is decoupled from the injection process. It has been shown that the fuel pressure plays a vital role for the general performance of the engine, affecting both emissions and efficiency, and it is carefully regulated to achieve optimal performance at different operating points. In an attempt to facilitate the development of the responsible control algorithms, a simulation framework has been requested. A model describing the complete work cycle of the high-pressure fuel system is developed and implemented in a Simulink environment. It is to a large extent based on the underlying physics and constructed in a modular manner, which allows for different engine configurations to be simulated. The modelled pressure signal is compared to experimental data at different operating points with promising results in capturing the transient behaviour from a low-level perspective. Additionally, it manages to replicate some of the pressure oscillations which has been observed in the real system and it shows good response to changes in the input signals. However, there are some areas which are subject to improvement since capturing the static pressure levels over longer drive cycles has proved to be a difficult task. Overall, the developed model serves as a starting point for future development and validation of control algorithms.

With increasing demands for lowering emissions from diesel engines, bio fuel has been introduced to the fuel mixture. This fuel is based on vegetable oil with a much smaller carbon footprint than fossil fuel. The chemical composition of bio fuel has lead to deposits forming inside the fuel injector in diesel engines, these deposits are usually denoted as Internal Diesel Injector Deposits (IDID). At Scania CV AB an injector test rig is designed with the goal of creating and investigating IDID. This project has made a theoretical investigation of how IDID are formed and how this affects the mechanics inside the injector. It has also analysed injector components from a worst case scenario perspective in order to find a testing method for creating IDID in the test rig. By analysing performance changes from a build-up perspective, where IDID decreases the tolerances inside the injector, as well as friction, formed when deposits cause injector mechanics to stick together, it has been found that injector performance does hardly change from build-up and that performance changes only occur when friction is introduced. From the injector component analysis it is found that the limiting factors in rig testing come from fuel system components rather than the injector itself. This is the base for a rig running test method presented.

[EN] This research work presents the study of a low pressure EGR loop influence on a SI gasoline turbocharged direct injection engine in steady and transient testing conditions, with an optimization process of the original engine calibration in order to minimize the engine fuel consumption when cooled EGR is introduced in steady testing conditions. The cooled EGR strategy was also evaluated operating in synergy with other fuel consumption reduction strategies, such as: lean burn, multi-injection, higher coolant temperature and in-cylinder induced swirl motion. To fulfill the main objectives of this research work, firstly, a methodical process was followed, where a global methodology was first developed in order to obtain high accuracy engine tests, based on the experimental tools chosen that could comply with the requirements of the testing conditions, and the appropriate theoretical tools and procedure to post-process the tests performed. Secondly, a specific methodology was developed for each stage of the study and testing conditions, taking into account optimization processes or parametric tests in order to study the effect of a single parameter on engine's outputs or optimize an engine parameter in order to minimize the engine fuel consumption. As a first stage of the study, a basic analysis of the impact of cooled EGR on the engine combustion, performance, air management and exhaust emissions is presented. Afterwards, an optimization of the combustion phasing in order to minimize the fuel consumption was performed, and therefore the potential of cooled EGR in order to reduce the engine fuel consumption was observed for low load, part load and full load engine conditions, for two different engine speeds. In addition, a study in transient conditions of the engine operating with cooled EGR was performed. NEDC cycles were performed with different EGR valve openings and therefore a comparison of different cooled EGR rates influence on the engine performance, air management and accumulated exhaust emissions was presented. The second stage, consisted in a methodology developed to optimize the VVT setting and injection timing, for part load engine conditions, in order to maximize the cooled EGR potential to reduce engine fuel consumption. After this optimization, a synergy analysis of the optimum engine condition operating with cooled EGR and three other engine fuel consumption reduction strategies was performed. These strategies were tested to investigate and evaluate the potential of increasing the cooled EGR operational range to further decrease the engine fuel consumption. Furthermore, a basic study of the potential to reduce the engine fuel consumption and impact on combustion, air management and exhaust emissions of a lean burn strategy, in part load engine conditions, was presented as introduction of the final study of the cooled EGR strategy operating in synergy with the lean burn strategy in order to investigate the potential to control the exhaust emissions and reduce the engine fuel consumption.
[ES] El objetivo de este trabajo de investigación es estudiar la influencia de un lazo de baja presión de EGR en las prestaciones de un motor de gasolina de encendido provocado turbosobrealimentado e inyección directa, en condiciones de ensayos estacionarios y transitorios, con un proceso de optimización de la calibración original del motor para minimizar el consumo de combustible del motor. La estrategia de "cooled EGR" fue también evaluada operando en sinergia con otras estrategias usadas para reducir el consumo de combustible del motor, entre ellas: mezcla pobre, múltiples inyecciones, operación a alta temperatura del fluido refrigerante del motor y movimiento de "swirl" inducido en el cilindro. Para cumplir con los objetivos mencionados, se siguió un proceso metódico donde previamente se desarrolló una metodología global para obtener resultados de indudable calidad, basados en el uso de herramientas experimentales que cumplieran con los requerimientos de las condiciones de ensayo, y las apropiadas herramientas teóricas y procedimiento para post-procesar los ensayos realizados. En segundo lugar, se desarrolló una metodología específica para cada etapa del estudio, teniendo en cuenta los procesos de optimización o estudios paramétricos que se pudieran realizar. Como primera etapa, se presenta un estudio básico del impacto del "cooled EGR" en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor. Seguidamente, se procedió a la optimización del centrado de la combustión con la finalidad de minimizar el consumo de combustible del motor y poder analizar el potencial del "cooled EGR" como estrategia de reducción de consumo de combustible. El estudio presentado se realizó para baja, media y alta carga del motor con dos diferentes regímenes de giro del motor. Adicionalmente, se llevó a cabo un estudio del motor operando en condiciones transitorias con "cooled EGR". Se realizaron una serie de ensayos usando el ciclo NEDC como base y se probaron diferentes estrategias sencillas de control de la apertura de la válvula de EGR para analizar la influencia del "cooled EGR" en condiciones transitorias. La segunda etapa consiste en el desarrollo de una metodología para optimizar los parámetros del diagrama de distribución (VVT) y el inicio de inyección, para cargas medias del motor, con la finalidad de maximizar el potencial de reducción de consumo de combustible de la estrategia "cooled EGR". Una vez realizada la optimización, se llevó a cabo un estudio usando la configuración óptima encontrada, operando en sinergia con otras tres estrategias usadas para reducir el consumo de combustible del motor. Estas estrategias fueron evaluadas con la finalidad de incrementar el rango de operación de la estrategia "cooled EGR" para lograr reducir aún más el consumo de combustible del motor. Adicionalmente, se llevó a cabo un estudio básico sobre la influencia de operar con mezcla pobre en la combustión, prestaciones, renovación de la carga y emisiones contaminantes del motor, como introducción al último estudio llevado a cabo sobre la posibilidad de usar la estrategia de mezcla pobre en conjunto con la estrategia de "cooled EGR", con la finalidad de analizar el potencial de controlar las emisiones contaminantes y reducir el consumo de combustible del motor al mismo tiempo.
[CAT] L'objectiu d'este treball d'investigació és estudiar la influència d'un llaç de baixa pressió d'EGR en les prestacions d'un motor de gasolina d'encesa provocat turbosobrealimentat i injecció directa, en condicions d'assajos estacionaris i transitoris, amb un procés d'optimització del calibratge original del motor per a minimitzar el consum de combustible del motor. L'estratègia de "cooled EGR" va ser també avaluada operand en sinergia amb altres estratègies usades per a reduir el consum de combustible del motor, entre elles: mescla pobra, múltiples injeccions, operació a alta temperatura del fluid refrigerant del motor i moviment de `"swirl" induït en el cilindre. Per a complir amb els objectius mencionats, es va seguir un procés metòdic on prèviament es va desenrotllar una metodologia global per a obtindre resultats d'indubtable qualitat, basats en l'ús de ferramentes experimentals que compliren amb els requeriments de les condicions d'assaig, i les apropiades ferramentes teòriques i procediment per a post- processar els assajos realitzats. En segon lloc, es va desenrotllar una metodologia específica per a cada etapa de l'estudi, tenint en compte els processos d'optimització o estudis paramètrics que es pogueren realitzar. Com a primera etapa, es presenta un estudi bàsic de l'impacte del "cooled EGR" en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor. A continuació, es va procedir a l'optimització del centrat de la combustió amb la finalitat de minimitzar el consum de combustible del motor i poder analitzar el potencial del "cooled EGR" com a estratègia de reducció de consum de combustible. L'estudi presentat es va realitzar per a baixa, mitja i alta càrrega del motor amb dos diferents règims de gir del motor. Addicionalment, es va dur a terme un estudi del motor operand en condicions transitòries amb "cooled EGR". Es van realitzar una sèrie d'assajos usant el cicle NEDC com a base i es van provar diferents estratègies senzilles de control de l'obertura de la vàlvula d'EGR per a analitzar la influència del "cooled EGR" en condicions transitòries. La segona etapa consistix en el desenrotllament d'una metodologia per a optimitzar els paràmetres del diagrama de distribució (VVT) i l'inici d'injecció, per a càrregues mitges del motor, amb la finalitat de maximitzar el potencial de reducció de consum de combustible de l'estratègia "cooled EGR". Una vegada realitzada l'optimització, es va dur a terme un estudi usant la configuració òptima trobada, operant en sinergia amb altres tres estratègies usades per a reduir el consum de combustible del motor. Estes estratègies van ser avaluades amb la finalitat d'incrementar el rang d'operació de l'estratègia "cooled EGR" per a aconseguir reduir encara més el consum de combustible del motor. Addicionalment, es va dur a terme un estudi bàsic sobre la influència d'operar amb mescla pobra en la combustió, prestacions, renovació de la càrrega i emissions contaminants del motor, com a introducció a l'últim estudi dut a terme sobre la possibilitat d'usar l'estratègia de mescla pobra en conjunt amb l'estratègia de "cooled EGR", amb la finalitat d'analitzar el potencial de controlar les emissions contaminants i reduir el consum de combustible del motor al mateix temps.
Rivas Perea, ME. (2016). Assessment of fuel consumption reduction strategies on a gasoline turbocharged direct injection engine with a cooled EGR system [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68497
TESIS

The aim of diploma thesis is the design of fuel system for the Caterpillar twelve cylinder spark ignited turbocharged engine. The fuel system is designed for sequential electronic controlled gas injection into intake manifold. Computational model of the engine was calculated in Lotus Engine simulation software. CFD analysis of mixing CNG with air was computed in Star CCM+ software.

Följande studie är gjord på uppdrag av Sjöfartsverket. I studien undersöktes hur en installation av ett Common Rail-system ombord på isbrytaren Ymer påverkat bränsleförbrukningen samt utsläppen av kväveoxider. Rådata som loggats ombord på Ymer har analyserat och bearbetat. Material och information från tillverkare, besättning samt teknisk chef på Sjöfartsverket, Albert Hagander har använts under studien. Tillsammans med uppmätta mätdata och tidigare gjord litteraturstudie stöds resultaten i studien. Det är ingen slump att system av Common Rail-typ redan är tillämpat inom de flesta branscher så som transport, personbilsindustri och jordbruk. Huvudsyftet med Common Rail är att minska bränsleåtgången samt minska utsläppen genom en renare och mer effektiv förbränning av bränslet.  Huvudsakligen undersöktes hur det nyinstallerade systemet påverkat bränsleförbrukningen och hur bränslebesparingen varierar med belastningen av maskinen. Vidare granskades hur utsläppen av kvävedioxider påverkats efter installationen. Problematiken med ökad NOx-produktion till följd av en högre förbränningstemperatur som Common Railsystemet medför diskuteras i rapporten. De resultat vi kommit fram till att en bränslebesparing kan göras ombord på Ymer genom att ersätta det gamla bränslesystemet med ett bränslesystem av Common Rail-typ. Vidare har installationen medfört andra förbättringar så som fartygsmaskinens reaktion på de många lastväxlingar som förekommer under isbrytning.
The following study has been carried out on behalf of Sjöfartsverket. The study examines how the installation of a common rail system on board the icebreaker Ymer affected fuel consumption and emissions of nitrogen oxides. The raw data logged on board Ymer was analyzed and processed. Materials and information from manufacturers, crew and the technical manager at the Swedish Maritime Administration, Albert Hagander have been used during the study. Together with measured data and previously made research study the findings of the study are supported. It is no coincidence that the system of the common rail type is already applied in most industries such as transport, car industry and agriculture. The main purpose of the Common Rail is to reduce fuel consumption and reduce emissions through cleaner and more efficient combustion of the fuel. We primarily examined how the newly installed system affected fuel consumption and the fuel savings will vary with the load of the machine. Furthermore, we examined how emissions of nitrogen oxides were affected after installation. The problem of increased NOx production due to a higher combustion temperature as the common rail system entails are discussed in the report. The result that was concluded was that fuel savings can be made on board Ymer by replacing the old fuel system with a common rail fuel type. Furthermore, the installation has brought other improvements such as ship machine's reaction to the many load changes that occur during icebreaking.

A utilização mais eficiente dos recursos naturais tem levado a indústria a aumentar a eficiência dos produtos manufaturados. Veículos de transporte Diesel estão incluídos neste cenário. Nos motores Diesel, um componente importante do sistema de injeção é o bico injetor. Uma legislação recente no Brasil introduziu limites de emissões EURO5. Estes novos parâmetros tiveram impacto no projeto do bico injetor com tolerâncias sendo reduzidas, em especial na área da sede do corpo do bico injetor, alterando o parâmetro funcional de pressão de abertura do produto. Neste cenário, o impacto desta superfície cônica retificada sobre a pressão de abertura é grande, bem como, sobre o desempenho do motor Diesel. Este estudo tem como objetivo analisar o defeito de topografia superficial típico e recorrente no processo de retificação interna cônica da sede do corpo dos bicos injetores. Um experimento planejado foi realizado de acordo com método Taguchi e determinou-se a relação sinal-ruído para dois parâmetros de topografia 2D. A superfície da sede também foi analisada utilizando análise topográfica 3D. Os resultados deste estudo incluem a indicação de possíveis causas do defeito recorrente, caracterização dos principais elementos do processo de retificação, caracterização da superfície retificada e otimização dos parâmetros do processo de retificação.
Industries of manufactured products have increased their efficiency optimizing the natural resources usage and Diesel commercial vehicles are included in this scenario. For Diesel engines, one of the most important components of the injection system is the nozzle injector. In Brazil, EURO5 legislation was recently introduced, bringing new emission limits for Diesel engines. Because of this, the nozzle injector design has changed and some manufacturing tolerances were reduced, in special the body seat geometry. This also changed the nozzle opening pressure. In this new process, the body seat grinded conical surface impacts on this functional parameter and consequently the Diesel engine performance. This study has as target to analyze a recurrent defect in the internal conic grinding process of the nozzle body seat. A trial was performed in this process according to Taguchi method and signal / noise ratio for 2D topographic parameters were defined. The body seat surface was also analyzed using 3D topographic analysis. The results of this study include the possible cause of the recurrent failure, characterization of the ground surface, process main elements integrity assessment and optimization of the grinding process parameters.

Resin Transfer Molding (RTM) is a procedure in composite material manufacturing in which resin and fibers are held apart until the last possible moment. In this way it can be contrasted with other manufacturing methods where the resin and fiber are combined prior to use. In RTM, unresinated fibers are held within a tool cavity and a differential pressure is applied to a supply of resin so that the resin flows into the reinforcement completely wetting it out. Reinforcements may be made of any fiber and the use of all forms has been reported, from unidirectional through woven or knitted cloths to needled and random mats and fully three-dimensional reinforcement preforms. The resin can be of a very wide range of chemistries and formulations, so long as the basic process requirements are met. Cure times can be from a few minutes to many hours. Resin injection machines vary widely, and production line design can be just as varied. The focus of this project will be the development of an intelligent injection system and its application to RTM. In order to achieve this, the Lab VIEW program will be employed to control pressure and flow rate—the two important parameters of RTM. This system includes an injector, computer, data acquisition boards, electric system and pneumatic system. A number of experiments have been performed to find the optimal application of this system. During the manufacturing of composite parts, all the processing parameters, such as temperature, pressure, flow rate and displacement with respect to time, can be written to a computer hard disk to be analyzed later. All the data acquired during the operation can help us to understand in depth the processing of composite materials and the relationship between process, quality and property.

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.

Particle behaviour during the downwards, pneumatic injection of powder into an aqueous medium (water) has been investigated by means of a new method which involves direct measurement by making use of an Aqueous Particle Sensor (APS) unit. Through this method, phenomena and parameters related to injection processes, such as gas-particle jet penetration distance, jet diameter, jet cone angle, particle dispersion and distribution within the liquid have been investigated both qualitatively and quantitatively. Flow observations comprised part of the experimental program for the purpose of confirming the characteristics of the "gas-only" and "gas-powder" injection regimes reported by previous workers.
The effect of gas and powder flow rates (powder/gas loading ratio) in determining the injection regimes and particle behaviour within the liquid were the main parameters investigated.
It was demonstrated that the jetting regime can be easily achieved as a result of increased momentum transfer from the particles to the gas phase. However, this required a high loading of particles. Entrainment of gas with the injected particles took place not only during coupled flow (jetting) but also during decoupled (bubbling) flow, such that some gas was always entrained by the particles and penetrated the liquid as a gas-particle jet, leaving large gas bubbles at the lance tip. It was further demonstrated that the gas flow rate had a greater effect on particle suspension within the liquid than did the powder flow rate.

The primary aim of this research was to predict the emissions and fuel savings when replacing a mechanical fuel oil injection system with a high pressure common rail one. The work in this study consists of two parts. In the first part, a novel routine is proposed for the optimisation of electronic fuel injectors and their dynamic response, including the needle valve opening delay and the needle valve closing delay (The needle valve opening delay refers to the delay between the control signal being trigged and the needle valve being fully open; the needle valve closing delay refers to the delay between the control signal deactivating and the needle valve being fully closed). Two injectors (Type-I and Type-II) were included; their one-dimensional (1D) models were built in AMESim software and validated respectively. A parametric study on the Type-I fuel injector was conducted before the optimisation process in order to examine the effects of various parameters including the control piston diameter (CPD), control oil (i.e. the fuel oil used for control in a typical solenoid electronic fuel injector) inlet passage diameter (IPD) and control oil outlet passage diameter (OPD) on injection characteristics, i.e. injection rate, injection mass, needle valve lift and control chamber pressure. Then, the optimisation of the injector dynamic response was investigated by the proposed routine in modeFRONTIER software. In detail, the routine included the following steps: First, a random sequence was adopted in the design of experiment (DOE) type. Then, an NSGA-II (Non-dominated Sorting Genetic Algorithm II) algorithm was selected. Next, a whole electronic fuel injector model was chosen, where the displacements of the needle valve were generated. These data were first written into an input file, and to do this, appropriate writing and reading rules needed to be developed. The text file was read by the MATLAB code, where the control signal and needle valve displacement timings were calculated. The valve opening delay and the valve closing delay were thus obtained from these timings. Additionally, a constraint was set between the control oil inlet passage diameter and control oil outlet passage diameter in that the former should be smaller than the latter in each run. The CPD, OPD and IPD were the three design parameters to be varied in the optimisation process of the Type-I fuel injector at a specific rail pressure. However, three more design parameters (the spring preload force (SPF), nozzle orifice number (NZN) and nozzle orifice diameter (NZD)) were involved in the optimisation process of the Type-II fuel injector under three different rail pressures (80 MPa, 120 MPa and 160 MPa). The optimal design with the best trade-off between the valve opening delay and the valve closing delay of each fuel injector was singled out via a scattering chart. Results show that the optimum Type-I fuel injector achieved reductions of 40% and 25% of the baseline design on the valve opening delay and valve closing delay respectively. The optimal design of the Type-II fuel injector also achieved a huge reduction at all three rail pressures. Specifically, the valve opening delay was reduced by 29.8%, 29.2% and 20.9%, and the valve closing delay was reduced by 25.6%, 24.5% and 30.1% at 80 MPa, 120 MPa and 160 MPa rail pressures respectively. RSM (response surface method) contour maps were used to study the interactions between design parameters. Results indicated that the CPD, IPD and OPD and their interactions are influential design parameters for the valve opening delay, while the IPD has a dominant effect on the valve closing delay. A large CPD together with a large IPD was found to increase the valve opening delay dramatically. Surprisingly, the effects of the spring preload force (SPF) on the valve closing delay are noticeable at low rail pressures. The valve closing delay decreases with an increase in the spring preload force. The feasibility and efficiency of the proposed routine was validated both on the Type-I fuel injector and the Type-II fuel injector. It was not only achieved great reductions on both the valve opening delay and the valve closing delay, but was also able to comprehensively disclose the effects and interactions of the design parameters on the injector dynamic response. In the second part, Type-II fuel injector matches with the combustion chamber of a medium-speed marine diesel engine was conducted by a CFD model of the medium-speed marine diesel engine built in AVL FIRE software. The model was validated by using the cylinder pressures, rate of heat release (ROHR) and NOx emissions under four engine loads, i.e. L25 (25%), L50 (50%), L75 (75%) and L100 (100%) loads. Seven engine design parameters, including four injection-related parameters (spray angle, nozzle protrusion length, injection timing and swirl ratio) and three combustion chamber geometry parameters (bowl diameter, centre crown height and toroidal radius), were examined by a parametric study and a multi-objective optimisation. The parametric study was carried out to discover the sensitivity of design parameters on the objectives (nitrogen oxides (NOx) emissions, soot emissions and specific fuel oil consumption (SFOC)). In it, each engine design parameter was investigated independently under three engine loads (25% engine load was excluded due to the fact that it is very unstable operating condition). Results showed that the injection-related parameters were found to have much more influence than the combustion chamber geometries. In addition, the injection timing, one of the injection-related parameters, has the largest influence on the objectives. In the optimisation study, two algorithms (the nonlinear programming by quadratic Lagrangian (NLPQL) algorithm and multi-objective genetic algorithm (MOGA)) were used in two stages, initially separately and then sequentially, for the first time in the engine optimisation domain. This study aims to reduce the NOx emission, soot emissions as well as to improve fuel economy. Detailed comparisons were made for NOx emissions, soot emissions and SFOC as well as the design parameters. The optimisation study showed that the NLPQL algorithm failed to obtain optimal designs whilst the MOGA offered more feasible Pareto designs. Since the NLPQL algorithm is a local optimisation method, and as a result it is affected by the selection of appropriate initial conditions. The optimal design with the best trade-off between NOx and soot emissions obtained by the MOGA was set as the starting point of the NLPQL algorithm. In this case, a better design with lower NOx emissions and soot emissions was obtained. The combustion processes of these optimal designs were also analysed and compared in detail. Late injection and small swirl ratio were reckoned to be the main reasons for reducing NOx emissions. In the end, contour maps generated by response surface method (RSM) were applied in order to gain a better understanding of the interaction and sensitivity of the design parameters on NOx emissions, soot emissions and SFOC. Results indicated that NOx emissions and soot emissions can be greatly reduced by adopting a late injection, a low swirl and a large spray angle, but fuel economy was sacrificed.

This thesis describes a combined 1-D numerical and experimental analysis of a GDI injection system. The aim is to design the GDI injection system to have the minimum injection variability between injectors. This is possible analysing the rail pressure waves that affect the injections. Thanks to a MATLAB numerical code the results coming from a first calibration attempt were compared with experimental data to verify the reliability of the acquired results. They were calculated after specific tests made on the hydraulic test bench developed at Lamborghini. Different configurations were studied changing the system geometry, such as rail diameter, high pressure pipe length and inlet position inside the rail, flow-restrictor diameter at the end of high pressure pipe. Eight different configurations were analysed and the one that showed the lowest CoV of injection was proposed as a final design. Then a 1-D numerical analysis of the GDI injection system was developed on the chosen configuration with the aim of predicting pressure waves propagation phenomena and the injected mass flow rate. The focus of the 1-D analysis is to verify through the comparison between simulated values and experimental ones if the model predicts accurately the physics of the system, in order to use it on a wider range of operating points. The following step consisted in controlling the GDI pump in MIL environment through a cosimulation between high pressure system model built in GT-ISE and control model made with Simulink. The high pressure control model was developed and validated. The aim was to have a closed loop control of the rail pressure using the same ECU control strategy. The main task of the control is to actuate the angle, respect to pump TDC, the MSV valve had to be closed to make the actual pressure follow the target one. The control model and the simulation in MIL environment are very useful since they help on the precalibration of ECU functions, reducing testing activities.

This diploma thesis is focused on examining the development of a diesel tractor engine with a newer injection system, concretely common-rail system. Mainly it is about the application of the high pressure fuel pump, fuel rail and injectors. With regard to the used components are appropriate adjustments made on the engine, and then checked using the available calculations. Brief mention is given to the theoretical summary of the contemporary state of applied injection system and its development trend. Selecting adjustments is primarily based on observed operating load. However, it is also striving to their simplest implementation. An integral part of this work is drawing documentation of newly designed components.

O objetivo do desenvolvimento do projeto foi minimizar uma das principais desvantagens no uso do gás natural veicular, que é a perda de potência, e aumentar sua eficiência volumétrica através da construção de um circuito eletrônico capaz de gerenciar de forma eficiente a injeção do gás. O aumento do rendimento é obtido através do gerenciamento eficiente da mistura ar-combustível utilizando um sistema de malha fechada. O gerenciamento da relação de potência e economia é conseguido com o uso simultâneo de gás natural e o combustível líquido. Nos sistemas de conversão atuais e nos veículos originais a gás natural, a perda de potência é compensada desligando o sistema de gás e utilizando somente o combustível líquido, sendo esta seleção feita de forma manual na maioria dos sistemas de conversão e de forma automática no Fiat Siena tetrafuel, não possibilitando o uso simultâneo do gás com o combustível líquido. A exigência de potência é medida através do ângulo do pedal do acelerador. Quando a exigência de potência é baixa, o sistema opera apenas com gás. No momento em que há solicitação de potência intermediária, o sistema opera com diferentes proporções de etanol e gás. Na situação de solicitação de potência máxima, é utilizado apenas o combustível líquido. Foram feitas comparações entre o sistema convencional e o sistema proposto, através de ensaios dinamométricos, rodoviários e emissão de poluentes. O veículo Volkswagen Gol com seu sistema original utilizando somente etanol possui potência máxima de 64,06 cavalos, (47,77 Kilowatts) e consumo de 12,6 quilômetros por litro de etanol. Com o sistema convencional de gás natural aspirado, o consumo foi de 21 quilômetros por metro cúbico e a potência não ultrapassou 51,82 cavalos (38,64 Kilowatts), com o protótipo desenvolvido a eficiência volumétrica aumentou 25% com consumo de 26,4 quilômetros por metro cúbico. O gerenciamento de potência proporciona potências intermediárias acima de 51,82 cavalos (38,64 Kilowatts), até a potência máxima de 64,06 cavalos (47,77 Kilowatts) em situações que uma maior potência é requerida. O sistema desenvolvido proporciona o benefício da flexibilidade no abastecimento disponível nos sistemas atuais, com a flexibilidade na potência não disponível nos sistemas atuais.
This project intended to minimize one of the main disadvantages of using natural gas vehicles, which was the loss of power, and increase their volumetric efficiency by building an electronic circuit able to efficiently manage the gas injection. The increase in volumetric efficiency is obtained through the efficient management of air-fuel mixture using a closed loop system. The management of the power and economy ratio is achieved with the simultaneous use of natural gas and liquid fuel. In the current conversion systems and original vehicles that use natural gas, the power loss is compensated by turning off the gas system and using only the liquid fuel. This selection is done manually in most conversion systems, and automatically at Fiat Siena Tetrafuel, not allowing the simultaneous use of gas to liquid fuel. The demand for power is measured by the angle of the accelerator pedal. When the power demand is low, the system operates only with natural gas. When intermediate power is required, the system operates with different proportions of ethanol and natural gas. For maximum power, only ethanol is used. Comparisons were made between the conventional and the proposed system through dynamometer tests, road tests and emission analyses. The Volkswagen Gol with original system using only ethanol has a maximum power of 64.06 horses (47.77 Kilowatts) and consumption of 12.6 kilometers per liter of ethanol. With conventional aspirated natural gas system, the consumption was 21 km per cubic meter and the power did not exceed 51.82 horses (38.64 Kilowatts). With the prototype, volumetric efficiency increases by 25%, with consumption of 26.4 kilometers per cubic meter. The power management provides intermediate powers up to 51.82 horses (38.64 Kilowatts) until the maximum power of 64.06 horses (47.77 Kilowatts) in situations where more power is required. The developed system provides the benefit of refueling flexibility found in the original system, with power flexibility not available in original systems.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The biodiesel use has become important due to its renewable character and to reduce environmental impacts during the fuel burning. Theses benefit will be valid if the fuel shows good performance, chemistry stability and compatibility with engines. Biodiesel is a good fuel to diesel engines due to its lubricity. Then, the aimed of this study was to verify the physicalchemistry properties of biodiesel and their correlations with possible elastomers damage after biodiesel be used as fuel in an injection system. The methodology was divided in three steps: biodiesels synthesis by transesterification of three vegetable oil (soybean, palm and sunflower) and their physical-chemistry characterization (viscosity, oxidative stability, flash point, acidity, humidity and density); pressurized test of compatibility between elastomers (NBR and VITON) and biodiesel, and the last one, analyze of biodiesels lubricity by tribological test ball-plan( HFRR). Also, the effect of mixture of biodiesel and diesel in different concentrations was evaluated. The results showed that VITON showed better compatibility with all biodiesel blends in relation to NBR, however when VITON had contact with sunflower biodiesel and its blends the swelling degree suffer higher influences due to biodiesel humidity. For others biodiesels and theirs blends, this elastomer kept its mechanical properties constant. The better tribological performance was observed for blends with high biodiesel concentration, lower friction coefficient was obtained when palm biodiesel was used. The main mechanisms observed during the HFRR tests were abrasive and oxidative wear
O uso do biodiesel tem ganhado for?a por seu car?ter renov?vel e por diminuir o impacto ambiental causado pela queima dos combust?veis f?sseis. Estes benef?cios valer?o a pena se o combust?vel apresentar bom desempenho, estabilidade qu?mica favor?vel e que n?o comprometa a integridade do sistema no qual venha a atuar. A sua aplica??o nos motores diesel tem sido indicada por apresentar maior lubricidade, que ? desej?vel para este sistema em raz?o do funcionamento da bomba. Desse modo, este trabalho teve como objetivo verificar o papel das propriedades f?sico-qu?micas do biodiesel e correlaciona-las com os poss?veis danos causados com o seu uso aos elast?meros aplicados no sistema de inje??o dos motores diesel. A metodologia foi dividida em tr?s etapas: s?ntese dos biodieseis por metan?lise a partir de tr?s oleaginosas (soja, dend? e girassol) e caracteriza??o f?sico-qu?mica (viscosidade, estabilidade oxidativa, ponto de fulgor, acidez, umidade e densidade); ensaio pressurizado de compatibilidade dos biodieseis com os elast?meros (NBR e VITON) e por fim, an?lise da lubricidade dos biodieseis atrav?s de ensaio tribol?gico esfera-plano( HFRR). Tamb?m foi avaliado o efeito da mistura do biodiesel ao diesel em diferentes propor??es, que limitam a deteriora??o dos materiais em contato com este combust?vel. O VITON apresentou maior compatibilidade com todos os combust?veis em rela??o ao NBR, no entanto para o contato com o biodiesel de Girassol e suas blendas o grau de inchamento sofreu maiores influ?ncias devido a este biodiesel apresentar maior umidade. Para as demais blendas e combust?veis analisados, este elast?mero manteve suas propriedades mec?nicas praticamente constantes. Em rela??o aos combust?veis estudados e suas blendas, os melhores desempenhos tribol?gicos foram observados para as maiores concentra??es dos biodieseis, com coeficientes de atrito menores para o biodiesel de dend?. Os principais mecanismos de desgaste observados foram abrasivo e oxidativo

Роботу виконано на кафедрі автомобілів Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України. Захист відбудеться 21 грудня 2020 р. о 12:30 годині на засіданні екзаменаційної комісії № 10 у Тернопільському національному технічному університеті імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Текстильна, 28, навчальний корпус № 9, ауд. 106.
В кваліфікаційній роботі розроблено технологію технічного обслуговування та ремонту системи керування двигуном Simtec 71 автомобіля Opel Vectra, а також досліджено конструктивні, функціональні та експлуатаційні властивості системи електронного керування акселерометром.
The qualification work developed the technology of maintenance and repair of the engine control system Simtec 71 car Opel Vectra, as well as investigated the design, functional and operational properties of the electronic control system accelerometer.
РEФEРAТ...6 ВCТУП...7 1 ЗAГAЛЬНО-ТEXНIЧНИЙ РОЗДIЛ...8 1.1 Характеристика автомобіля Opel Vectra...8 1.2 Призначення системи керування двигуном Simtec 71...10 2 ТEXНОЛОГIЧНИЙ РОЗДIЛ...11 2.1 Особливості побудови та функціонування системи керування автомобіля Opel Vectra...11 2.2 Розпізнавання пропусків запалювання...15 2.3 Діагностика роботи каталізатора...18 2.4 Діагностика роботи лямбда-зондів...21 2.5 Діагностика вентиляції бака...25 2.6 Діагностика системи впуску додаткового повітря...27 2.7 Діагностика паливної системи...28 2.8 Корекція регулювання паливно-повітряної суміші...31 3 КОНCТРУКТОРCЬКИЙ РОЗДIЛ...35 3.1 Аналіз існуючого устаткування для діагностики компонентів комплексної системи керування ДВЗ...35 3.2 Сканер напівпрофесійного обладнання для діагностики...40 3.3 Електричний розрахунок електронного ключа...42 4 НAУКОВО-ДОCЛIДНИЙ РОЗДIЛ...44 4.1 Аналіз особливості конструкції СЕКА...44 4.2 Дослідження робочого процесу системи електронного керування акселератором...45 4.3 Алгоритм діагностики операції та здійснення формування технічної документації...49 5 ОXОРОНA ПРAЦI ТA БEЗПEКA В НAДЗВИЧAЙНИX CИТУAЦIЯX...50 5.1 Охорна праці на дільниці діагностики...50 5.2 Техніка безпеки на дільниці діагностики...52 5.3 Розрахунок занулення...55 ЗАГАЛЬНІ ВИСНОВКИ ЩОДО КВАЛІФІКАЦІЙНОЇ РОБОТИ...62 БІБЛІОГРАФІЯ...63 ДОДAТКИ

В кваліфікаційній роботі розроблено дільницю ремонтного цеху для технічного обслуговування та ремонту системи живлення дизельного двигуна автомобіля MAN TGL з дослідженням теплового балансу, індикаторних та ефективних показників роботи двигуна на дизельному паливі і біопаливі.
Іn this graduation thesis of the repair shop section for maintenance and repair of the diesel engine power supply system of the MAN TGL car with research of thermal balance, indicator and effective indicators of operation of the engine on diesel fuel and biofuel.
РEФEРAТ. ВCТУП. 1 ЗAГAЛЬНО-ТEXНIЧНИЙ РОЗДIЛ. 1.1 Характеристика підприємства та його структура. 1.2 Режим роботи, режим праці і відпочинку працюючих. 1.3 Критичні фактори успіху підприємства, потенційні проблеми та ризики. 1.4 Робота по розвитку підприємства. 1.5 Характеристика дільниці. Недоліки в організації роботи дільниці та пропозиції щодо реконструкції. 1.6 Загальні відомості і технічна характеристика автомобіля MAN. 1.7 Common Rail - загальний принцип роботи. 2 ТEXНОЛОГIЧНИЙ РОЗДIЛ. 2.1 Будова основних елементів системи Common Rail. 2.2 Зняття і встановлення паливних форсунок. 2.3 Перевірка форсунки дизельного ДВЗ. 2.4 Визначення норм часу на ремонт елементів системи живлення. 3 КОНCТРУКТОРCЬКИЙ РОЗДIЛ. 3.1 Опис пристосування, що пропонується для використання при виконанні технологічного процесу. 3.2 Використання стенда. 3.3 Перевірка форсунок BOSH (соленоїдного типу). 3.3.1 Перевірка форсунок. Перевірка відкриття форсунок на низькому тиску. 3.3.2 Перевірка шумності сопла електромагнітної форсунки. 3.3.3 Величина продуктивності подачі суміші прямого і зворотного потоку. 3.3.4 Перевірка розпилення форсунок. 3.3.5 Перевірка насоса Common Rail. 3.4 Використання ультразвукової ванни. 3.5 Прилад для перевірки електромагнітних і п'єзоелектричних дизельних форсунок «Пульсар-дизель CR». 4 НAУКОВО-ДОCЛIДНИЙ РОЗДIЛ. 4.1 Аналіз показників та характеристик дизельного палива і рослинного масла для застосування в паливній системі. 4.2 Дослідження теплових характеристик та розрахунок двигуна при застосуванні альтернативного та дизельного палива. 4.3 Індикаторні показники роботи двигуна. 4.4 Ефективні показники роботи двигуна. 4.5 Дослідження теплового балансу двигуна. 4.6 Дослідження конструктивних особливостей та характеристик нагрівача біопалива в системі вприску двигуна. 4.7 Дослідження та розрахунок основних параметрів теплопередаючого елемента в нагрівачі системи вприску палива. 5 ОXОРОНA ПРAЦI ТA БEЗПEКA В НAДЗВИЧAЙНИX CИТУAЦIЯX. 5.1 Характеристика дільниці з точки зору охорони праці та заходи по покращенню умов праці. 5.2 Навчання з питань охорони праці…. 5.3 Розрахунок штучного освітлення моторної дільниці. ЗАГАЛЬНІ ВИСНОВКИ ЩОДО МАГІСТЕРСЬКОЇ РОБОТИ. БІБЛІОГРАФІЯ. ДОДAТКИ.

Роботу виконано на кафедрі автомобілів Тернопільського національного технічного університету імені Івана Пулюя Міністерства освіти і науки України. Захист відбудеться 22 грудня 2020 р. о 10:00 годині на засіданні екзаменаційної комісії № 10 у Тернопільському національному технічному університеті імені Івана Пулюя за адресою: 46001, м. Тернопіль, вул. Текстильна, 28, навчальний корпус № 9, ауд. 106.
В кваліфікаційній роботі розроблено технологію технічного обслуговування та ремонту системи керування двигуном автомобіля Skoda Octavia, а також досліджено ефективні характеристики та побудову дослідної установки.
The qualification work developed the technology of maintenance and repair of the engine control system of the car Skoda Octavia, as well as the effective characteristics and construction of the experimental installation.
РEФEРAТ...6 ВCТУП...7 1 ЗAГAЛЬНО-ТEXНIЧНИЙ РОЗДIЛ...8 1.1 Характеристика автомобіля Škoda Octavia III...8 1.2 Будова і принцип роботи комплексної системи керування двигуном автомобіля Škoda Octavia III...12 2 ТEXНОЛОГIЧНИЙ РОЗДIЛ...16 2.1 Функціонування системи керування двигуном...16 2.2 Перевірка системи вприску та тиску в паливній системі...18 2.3 Перевірка продуктивності паливного насоса...19 2.4 Перевірка форсунок...20 2.5 Технічне обслуговування системи вприску палива ...22 2.5.1 Заміна паливного фільтра...22 2.5.2 Очистка системи вприску палива...24 2.6 Аналіз використання обладнання для діагностики ЕСК ДВЗ...26 2.7 Розробка технологічного процесу проведення робіт на дільниці...30 2.8 Технологічний процес та вибір обладнання для промивки системи вприску Призначення і характеристики...32 3 КОНCТРУКТОРCЬКИЙ РОЗДIЛ...36 3.1 Аналіз існуючих пристроїв для перевірки комплексних систем керування двигуном...36 3.2 Аналіз пристосування для запресовки фільтра форсунки...39 3.3 Стенд для ультразвукової очистки перевірки форсунок та виконувані на ньому операції...40 4 НAУКОВО-ДОCЛIДНИЙ РОЗДIЛ...53 4.1 Аналіз процесів дослідження...53 4.2 Опис будови та принципу роботи дослідної установки...55 5 ОXОРОНA ПРAЦI ТA БEЗПEКA В НAДЗВИЧAЙНИX CИТУAЦIЯX...59 5.1 Оцінка виникнення аварій і травм в процесі діагностування та ремонту бензинових двигунів з електронними системами керування...59 5.2 Основні вимоги пожежної безпеки...61 5.3 Техніка безпеки на дільниці та при експлуатації стенду ...62 5.4 Розрахунок штучного освітлення...63 ЗАГАЛЬНІ ВИСНОВКИ ...66 БІБЛІОГРАФІЯ...67 ДОДAТКИ

La législation sur les émissions de polluants des Moteurs à Combustion Interne (ICEs) est de plus en plus contraignante et représente un gros défi pour les constructeurs automobiles. De nouvelles stratégies de combustion telles que la Combustion à Allumage par Compression Homogène (HCCI) et l’exploitation de stratégies d’injections multiples sont des voies prometteuses qui permettent de respecter les normes sur les émissions de NOx et de suies, du fait que la combustion a lieu dans un mélange très dilué et par conséquent à basse température. Ces aspects demandent la création d’outils numériques adaptés à ces nouveaux défis. Cette thèse présente le développement d’un nouveau modèle 0D de combustion Diesel HCCI : le dual Combustion Model (dual - CM). Le modèle dual-CM a été basé sur l’approche PCM-FPI utilisée en Mécanique des Fluides Numérique (CFD) 3D, qui permet de prédire les caractéristiques de l’auto-allumage et du dégagement de chaleur de tous les modes de combustion Diesel. Afin d’adapter l’approche PCM-FPI à un formalisme 0D, il est fondamental de décrire précisément le mélange à l’intérieur du cylindre. Par consequent, des modèles d’évaporation du carburant liquide, de formation de la zone de mélange et de variance de la fraction de mélange, qui permettent d’avoir une description détaillée des proprietés thermochimiques locales du mélange y compris pour des configurations adoptant des stratégies d’injections multiples, sont proposés. Dans une première phase, les résultats du modèle ont été comparés aux résultats du modèle 3D. Ensuite, le modèle dual-CM a été validé sur une grande base de données expérimentales; compte tenu du bon accord avec l’expérience et du temps de calcul réduit, l’approche présentée s’est montrée prometteuse pour des applications de type simulation système. Pour conclure, les limites des hypothèses utilisées dans dual-CM ont été investiguées et des perspectives pour les dévélopements futurs ont été proposées
More and more stringent restrictions concerning the pollutant emissions of Internal Combustion Engines (ICEs) constitute a major challenge for the automotive industry. New combustion strategies such as Homogeneous Charge Compression Ignition (HCCI) and the implementation of complex injection strategies are promising solutions for achieving the imposed emission standards as they permit low NOx and soot emissions, via lean and highly diluted combustions, thus assuring low combustion temperatures. This requires the creation of numerical tools adapted to these new challenges. This Ph.D presents the development of a new 0D Diesel HCCI combustion model : the dual Combustion Model (dual−CM ). The dual-CM is based on the PCM-FPI approach used in 3D CFD, which allows to predict the characteristics of Auto-Ignition and Heat Release for all Diesel combustion modes. In order to adapt the PCM-FPI approach to a 0D formalism, a good description of the in-cylinder mixture is fundamental. Consequently, adapted models for liquid fuel evaporation, mixing zone formation and mixture fraction variance, which allow to have a detailed description of the local thermochemical properties of the mixture even in configurations adopting multiple injection strategies, are proposed. The results of the 0D model are compared in an initial step to the 3D CFD results. Then, the dual-CM is validated against a large experimental database; considering the good agreement with the experiments and low CPU costs, the presented approach is shown to be promising for global engine system simulations. Finally, the limits of the hypotheses made in the dual-CM are investigated and perspectives for future developments are proposed

Les industries automobile et aéronautique sont confrontées dans le futur proche à une raréfaction des carburants fossiles, ainsi qu'au problème de pollution de l'environnement émis par les systèmes propulsifs. Pour s'affranchir de ces problèmes, l'utilisation de carburants alternatifs censés apporter rendement et préservation de l'environnement, s'est considérablement développée ces derniers temps. Cependant, leurs impacts sur la pollution, consommation et rendement de combustion ne sont toujours pas clairement établis. En particulier, il est nécessaire de quantifier leurs effets sur les phénomènes physiques clés à la base des processus que sont l'évaporation du carburant liquide et le mélange carburant vapeur/air. L'analyse expérimentale de ces processus physiques nécessite alors l'emploi de diagnostics lasers non-intrusifs et quantitatifs, permettant de mesurer des grandeurs physiques comme les distributions spatiales instantanées de température et de concentration du carburant en phase vapeur. Parmi les techniques optiques les plus attrayantes, l'imagerie de fluorescence induite par laser (PLIF) offre de nombreux avantages. L'objectif de la thèse a été, dans un premier temps, de caractériser les propriétés spectroscopiques de quatre carburants multi-composants, le kérosène (Jet A1), le Biomass-to-Liquid (BtL), le Diesel et l'Ester Méthylique Huile Végétale (EMHV) qui, mis à part le premier, possèdent des propriétés spectroscopiques encore peu connues. L'exploitation de leurs propriétés de fluorescence a ensuite permis d'évaluer leurs capacités à fournir des signaux autorisant la mesure de la température et de la concentration du carburant en phase vapeur. Dans un second temps, un étude exhaustive des propriétés de fluorescence de plusieurs cétones (3-pentanone, benzophénone) et aromatiques (fluoranthène, acénaphtène, naphtalène, 1,2,4-triméthylbenzène...) en fonction de la température et du quenching de l'oxygène moléculaire, a été réalisée à pression atmosphérique pour identifier les traceurs fluorescents potentiellement adaptés au dosage optique des quatre carburants. Les données photophysiques collectées ont ensuite été utilisées pour parfaire l'établissement des couples carburants/traceurs fluorescents ainsi que les stratégies de mesures de température et de concentration de carburant associées. L'exploitation des données acquises lors de différentes campagnes de mesures a ainsi mis en évidence la possibilité de détecter simultanément la fluorescence de plusieurs molécules aromatiques (mono-, di- et/ou tri-aromatique) naturellement présentes ou ajoutées artificiellement dans les carburants. Le cas du Diesel a nécessité le développement d'un carburant modèle pour permettre une étude de son évaporation. L'application de cette nouvelle approche PLIF a été validée sur un injecteur hélicoptère LPP de nouvelle génération fonctionnant avec trois carburants spécifiques que sont le Jet A1, le BtL et un mélange Jet A1/BtL

碩士
元智大學
機械工程學系
106
The engines of small unmanned aerial vehicle are mostly carburetor engine in used. And the carburetor is sensitive to environmental changes, so it needs to be adjusted often. However, the electronic fuel injection engine can precisely control the fuel supply, reduce fuel consumption and increase flight time. The purpose of this study is to build an electronic fuel injection engine system for small unmanned aircraft, using a four-stroke 50cc scooter engine as the experimental object. Then replace the carburetor of the scooter with the electronic fuel injection component developed by Ecotrons, and design an ECU to integrate the components. Finally, test and compare two fuel supply strategies, and the ignition control is added to complete the fuel injection and ignition control.

Thesis (M.S.)--University of Wisconsin--Madison, 2002.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 152-156).

Societal concerns on combustion-based fuel consumption are ever-increasing. With respect to internal combustion engines, this translates to a need to increase brake fuel conversion efficiency (BFCE). Diesel engines are a relatively efficient internal combustion engine to consider for numerous applications, but associated actions to mitigate certain exhaust emissions have generally deteriorated engine efficiency. Conventionally, diesel engine emission control has centered on in-cylinder techniques. Although these continue to hold promise, the industry trend is presently favoring the use of after-treatment devices which create new opportunities to improve the diesel engine's brake fuel conversion efficiency. This study focuses on injection timing effects on the combustion processes, engine efficiency, and the engine system's responses. The engine in the study is a medium duty diesel engine (capable of meeting US EPA Tier III off road emission standards) equipped with common rail direct fuel injection, variable geometry turbo charging, and interfaced with a custom built engine controller. The study found that injection timing greatly affected BFCE by changing the combustion phasing. BFCE would increase up to a maximum then begin to decrease as phasing became less favorable. Combustion phasing would change from being mostly mixing controlled combustion to premixed combustion as injection timing would advance allowing more time for fuel to mix during the ignition delay. Combustion phasing, in turn, would influence many other engine parameters. As injection timing is advanced, in-cylinder temperatures and pressures amplify, and intake and exhaust manifold pressures deteriorate. Rate of heat release and rate of heat transfer increase when injection timing is advanced. Turbocharger speed falls with the advancing injection timing. Torque, however, rose to a maximum then fell off again even though engine speed and fueling rate were held constant between different injection timings. Interestingly, the coefficient of heat transfer changes from a two peak curve to a smooth one peak curve as the injection timing is advanced further. The major conclusion of the study is that injection advance both positively and negatively influences the diesel engine's response which contributes to the brake fuel conversion efficiency.

碩士
國立虎尾科技大學
機械與機電工程研究所
97
Nowadays the measurements of the sensor signal of the engine management system in the vehicle are special purpose diagnostic tools which are primarily provided by the trade car makers. However, these instruments are often limited by the memory size of the hardware itself. This is the reason why the vehicle servicemen fail to monitor the frequency and time instant of the intermittent faults of the various sensors in engine management system over a long period of time. The objective of this research is to develop a data acquisition application program with Chinese human interface which runs in the Windows operating system environment. The research divides into two aspects: the hardware and the software. The hardware of the research mainly consists of the USB - 4711A data acquisition card produced by ADVANTECH and the Fluck 98 automotive scope. By comparing the functionality and the accuracy of measurement we can estimate the performances of the two equipments. In the software aspect, we develop the functionalities and human interfaces of the application program by using MFC of Microsoft Visual Studio 2005. The windows of the application program consist of the Profile demonstration, the parameters configuration, and the setting of voltage scale as well as time base. The functionalities of the data acquisition includes: loading from the files and displaying the results which are measured real-time from the various sensor signals. The experiment results demonstrate that the data acquisition system developed in the research is more accurate than the Fluck 98 automotive scope. The developed data acquisition system is more excellent than the Fluke 98 automotive scope in resolution, transmitting speed and flexibility. According to the results of the research, the developed data acquisition system except can satisfy the demands of the engine repair and the performance analysis. It can also save the expenses the vehicles repair needed including the repair time, spare parts, as well as has the elastic merit and so on. It’s not only a powerful and quick engine repair system but it is also a new learning system. It not only helps the servicemen speeding up the services but also increases the accuracy when diagnosis a fault engine.

碩士
國立臺北科技大學
車輛工程系碩士班
92
This research is a parametric study for a commercialized four-stroke 125c.c. electronic fuel injection (EFI) motorcycle engine. The electronic control unit (ECU) with 8-bit of original engine is replaced by a Motorola MC68376 32-bit microprocessor, The main purpose is to study effects of injection timing and spark advance on engine combustion characteristics and performance at various engine speed and throttle position. Then, relationship between the control variables, injection timing and spark advance, and engine performance will be set up. The conclusions from exponential results are as follows: 1. It will be easier and more flexible to adopt the embedded control system for the varies of engine control parameters. And it can reduce the time and cost for engine control system design. 2. Fuel injection timing should be varied according to the condition of engine speed and throttle position. The excess advance or delay of spark timing will affect severely to engine performance, fuel consumption, and exhaust emissions. Furthermore it will even cause engine misfire. 3. The horsepower and torque of an engine with spark timing varies with engine speed only are lower than that of an engine with spark timing varies with speed and load. The previous one also causes higher specific fuel consumption. Therefore, spark timing has to be properly controlled according to engine speed and load. 4. In the same throttle position, the minimum-spark-advance for beset torque (MBT) will be a little advanced with the increase of engine speed. That will increase the engine performance and reduce fuel consumption and exhaust emission. The experimental results of this thesis will provide a good reference for the design of motorcycle fuel injection system control. Furthermore it can reach the purpose of energy-saving, low exhaust emissions, and high engine performance.