Tesi sul tema "Diesel motor – Fuel systems"

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1

Arter, Micah. "The effects of diesel fuel density on fuel consumption measurements of portable in-use emissions measurement systems". Morgantown, W. Va. : [West Virginia University Libraries], 2007. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=5509.

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Thesis (M.S.)--West Virginia University, 2007.
Title from document title page. Document formatted into pages; contains vii, 91 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 60-62).
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2

Tran, Xuan-Thien Mechanical &amp Manufacturing Engineering Faculty of Engineering UNSW. "Modelling and simulation of electronically controlled diesel injectors". Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2003. http://handle.unsw.edu.au/1959.4/19278.

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The study presents a one-dimensional, transient and compressible flow models of a commercial Common Rail Injector (CRI) and a prototype of a single-fuel Hydraulically actuated Electrically controlled Unit Injector (HEUI) developed at the University of New South Wales (UNSW) in conjunction with local industry. The unique feature of the UNSW HEUI is the fact that it uses diesel fuel as the driver for pressure amplification within the unit injector. The work undertaken is part of a wider study aimed at optimization of the design of diesel injectors for dual-fuel systems to reduce green house gas emissions. The contribution of this thesis is the development of the model of the UNSW HEUI injector, which can be used to investigate possible modifications of the injector for its use in dual-fuel injection systems. The developed models include electrical, mechanical and hydraulic subsystems present in the injectors. They are based on Kirchhoff??s laws, on the mass and momentum conservation equations and on the equilibrium of forces. The models were implemented in MATLAB/SIMULINK graphical software environment, which provides a high degree of flexibility and allows simulation of both linear and nonlinear elements. The models were used to perform sensitivity analysis of both injectors. The sensitivity analysis has revealed that the temperature of the solenoid coil is one of the critical parameters affecting the timing and the quantity of the fuel injection of both injectors. Additional critical parameters were found to be the dimensions of the piston of the CRI, the stiffness of the needle spring of the HEUI and the dimensions of the intensifier of the HEUI. The models also revealed that in the case of pilot injections the speed of the solenoid is the major limiting factor of the performance. The developed models provide better understanding of the issues and limitations of the injectors. They give detailed insight into their working principles. The investigations of the models permit making quantitative analysis of the timing of the HEUI solenoid and to evaluate the proposed change of the direction of the pressure acting on the HEUI solenoid plunger.
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3

Chien, Jui-Yu. "The future and outlook of alternative fuel bus industry and its marketing strategy". CSUSB ScholarWorks, 2002. https://scholarworks.lib.csusb.edu/etd-project/2332.

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According to the current governmental regulations, all diesel buses will be replaced in the United States and the European market within the next ten years. There are over 60,000 buses in the United States and each year over 3,000 new buses of approximately 40 feet in length are purchased. The bus market has a growth rate of four to five percent per year over the last two years. The improvements in technology offered by United States companies prove unsatisfactory in terms of bus performance and the emissions of new buses. The energy crisis in the United States and concern over the health hazards of the diesel fuel exhaust gases and particulates, alternative fuel vehicles are in great demand in the transit market world wide.
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4

Toral, del Rio Maria Isabel. "An analysis of the influence of phosphorus poisoning on the exhaust emission after treatement systems of light-duty diesel vehicles". Thesis, Nelson Mandela Metropolitan University, 2007. http://hdl.handle.net/10948/697.

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Climate change has become a discussion topic of exponentially increasing urgency and importance amoung world leaders of all disciplines. These changes are brought about by the emission of so-called Greenhouse gases from various human activities. The primary cause of CO2 emissions is the burning of the Earth’s supply of nonrenewable natural fossil fuels like coal, oil and natural gas. The world first agreed on the prevention of “dangerous” climatic changes at the Earth Summit in 1992. The Kyoto Protocol of 1997 was the first step toward protection of the atmosphere and prescribes restrictions on emission pollutants. Since then the vehicle gas emissions are being controlled by means of different gas emissions norms, like the European Union Norm in Europe. The automotive manufacturers and suppliers are collectively working on reducing overall vehicle emissions. They are focusing on several different emission limiting possibilities, for example improved engine design, special fuel development and exhaust gas treatment systems. The exhaust gas treatment process requires continuous controlling and management of the exhaust gas emissions while driving a vehicle. Certain factors such as high emission temperatures have a negative influence on the life span of these systems. Their functionality and durability is also known to be reduced by the presence of chemical poisoning species like sulphur, phosphorus, zinc and calcium. The chemical poisoning species are produced during combustion of fuel and engine oil. They are therefore contained in the exhaust emissions and can poison the catalyst when passing over it. Phosphorous poisoning is particularly problematic and should be reduced considerably. This study involves the investigation of the phosphorous poisoning process and aims to provide clarity regarding the influences of different fuel and oil compositions on the severity of the process. Engine oil and biodiesel are two major sources of phosphorous poisoning. The phosphorus contained in biodiesel fuel is a natural component and can be minimized during the refining procedure. In contrast to others studies, the biodiesel fuel used during this project was SME (Soya Methyl Ester) with a 20% biodiesel content. This choice of fuel was made because of the increasingly important role that this type of biodiesel is playing in the European market and the future tendency to increase the percentage of biodiesel in the mixture with standard diesel fuel. The phosphorus contained in engine oil is a necessary additive to retain the antioxidant and anti-wear properties of the oil. This study examined the poisoning influences from the most commonly used phosphorus containing oil additive, Zinc Dithiophosphates (ZDDP), as well as a Zn-free, phosphorus containing anti-wear oil additive. This formulation provides information about the phosphorus poisoning process as caused by the engine oil in the absence of Zn in the oil additives. The results show how the phosphorus content in biodiesel fuel affects the functionality of the exhaust gas treatment systems and the importance of reducing the permitted content of phosphorus contained in the fuel. Reducing the phosphorus content in the fuel will conserve the functionality of the exhaust gas treatment systems during their operational life and thereby protect the environmental from emission pollutants. It also provides insight into the differences in the poisoning processes when the phosphorus deposited on the catalyst comes from biodiesel fuel and when it comes from the engine oil. Finally the results also illustrate the influence of different phosphorous forms contained in engine oil additives on the catalyst poisoning process. This information could be used for the development of new oil additive formulations.
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5

Douxchamps, Pierre-Alexis. "Diesel thermal management optimization for effective efficiency improvement". Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210123.

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This work focuses on the cooling of diesel engines. Facing heavy constraints such

as emissions control or fossil energy management, political leaders are forcing car

manufacturers to drastically reduce the fuel consumption of passenger vehicles. For

instance, in Europe, this fuel consumption has to reach 120 g CO2 km by 2012, namely 25 % reduction from today's level.

Such objectives can only be reached with an optimization of all engines components

from injection strategies to power steering. A classical energy balance of an internal

combustion engine shows four main losses: enthalpy losses at the exhaust, heat

transfer to the cylinder walls, friction losses and external devices driving. An

optimized cooling will improve three of them: the heat transfer losses by increasing

the cylinder walls temperature, the friction losses by reducing the oil viscosity and

the coolant pump power consumption.

A model is first built to simulate the engine thermal behavior from the combustion

itself to the temperatures of the different engine components. It is composed by two

models with different time scales. First, a thermodynamic model computes the in cylinder

pressure and temperature as well as the heat flows for each crank angle.

These heat flows are the main input parameters for the second model: the nodal

one. This last model computes all the engine components temperatures according

to the nodal model theory. The cylinder walls temperature is then given back to

the thermodynamic model to compute the heat flows.

The models are then validated through test bench measurements giving excellent

results for both Mean Effective Pressure and fluids (coolant and oil) temperatures.

The used engine is a 1.9l displacement turbocharged piston engine equipped with

an in-cylinder pressure sensor for the thermodynamic model validation and thermocouples

for the nodal model validation.

The model is then used to optimize the coolant mass flow rate as a function of

the engine temperature level. Simulations have been done for both stationary

conditions with effciency improvement up to 7% for specific points (low load, high

engine speed) and transient ones with a heating time improvement of about 2000s.

This gains are then validated on the test bench showing again good agreement.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

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6

Kotze, Johan. "A comparative study on the performance of biodiesel in a modern 1.9L turbo diesel engine". Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4293.

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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
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7

Strouhal, Pavel. "Aplikace vysokotlakého palivového systému na vznětový motor". Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254441.

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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.
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8

Tugsal, Umut. "FAULT DIAGNOSIS OF ELECTRONIC FUEL CONTROL (EFC) VALVES VIA DYNAMIC PERFORMANCE TEST METHOD". ProQuest, 2009. http://hdl.handle.net/1805/2094.

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Indiana University-Purdue University Indianapolis (IUPUI)
Electronic Fuel Control (EFC) valve regulates fuel flow to the injector fuel supply line in the Cummins Pressure Time (PT) fuel system. The EFC system controls the fuel flow by means of a variable orifice that is electrically actuated. The supplier of the EFC valves inspects all parts before they are sent out. Their inspection test results provide a characteristic curve which shows the relationship between pressure and current provided to the EFC valve. This curve documents the steady state characteristics of the valve but does not adequately capture its dynamic response. A dynamic test procedure is developed in order to evaluate the performance of the EFC valves. The test itself helps to understand the effects that proposed design changes will have on the stability of the overall engine system. A by product of this test is the ability to evaluate returned EFC valves that have experienced stability issues. The test determines whether an EFC valve is faulted or not before it goes out to prime time use. The characteristics of a good valve and bad valve can be observed after the dynamic test. In this thesis, a mathematical model has been combined with experimental research to investigate and understand the behavior of the characteristics of different types of EFC valves. The model takes into account the dynamics of the electrical and mechanical portions of the EFC valves. System Identification has been addressed to determine the transfer functions of the different types of EFC valves that were experimented. Methods have been used both in frequency domain as well as time domain. Also, based on the characteristic patterns exhibited by the EFC valves, fuzzy logic has been implemented for the use of pattern classification.
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9

Gill, Simaranjit Singh. "Controlling diesel NO_x & PM emissions using fuel components and enhanced aftertreatment techniques : developing the next generation emission control system". Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3643/.

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The following research thesis focuses on methods of controlling nitrogen oxides (NO_x) and particulate matter (PM) emissions emitted from a low temperature diesel exhaust. This involves studying the influence of hydrogen (H₂) on various aftertreatment devices such as hydrocarbon selective catalytic reduction (HC-SCR) over silver-alumina (Ag-Al₂O₃) catalysts for lean NO_x reduction, platinum diesel oxidation catalysts (DOC) for nitrogen dioxide (NO₂) production and passive regeneration methods for the diesel particulate filter (DPF). H₂ was implemented on-board either through diesel exhaust gas fuel reforming or via the simulation of ammonia (NH₃) dissociation. Both methods showed to be very effective in enhancing the activity of a silver HC-SCR catalyst for the reduction of NO_x with conversions reaching 90% with the aid of an upstream DPF. A combined DOC and catalysed DPF (cDPF) configuration proved promising for passive regeneration in the presence of reformed exhaust gas recirculation (REGR). The addition of H₂ over the DOC led to an improved catalyst light-off temperature and increased rate of oxidation for NO₂ production. Implementing filtered EGR (FEGR) removes the hydrocarbon (HC) and soot recirculation penalty, thus minimising particulate growth which results in a significantly reduced engine-out soot emission during exhaust gas recirculation (EGR) and hence, an improved NO_x/soot ratio. Introducing fuel components which enhance the cetane number and oxygenate the diesel fuel allow better control of the NO_x/soot trade-off with improved soot oxidation properties.
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10

Bilha, Vitor Meira. "Análise do processo de retificação interna aplicado à fabricação de bicos injetores diesel". Universidade Tecnológica Federal do Paraná, 2015. http://repositorio.utfpr.edu.br/jspui/handle/1/1889.

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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.
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11

Park, Talus. "Dual fuel conversion of a direct injection diesel engine". Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=460.

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Thesis (M.S.)--West Virginia University, 1999.
Title from document title page. Document formatted into pages; contains x, 96 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 61-62).
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12

Rosa, Josimar Souza. "Estudo de um motor ciclo diesel monocilíndrico bi-combustível". Universidade do Vale do Rio dos Sinos, 2014. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3459.

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Este trabalho buscou analisar o funcionamento de um motor de combustão interna (ciclo Diesel) operando com misturas parciais de óleo diesel com gás natural veicular, e óleo de soja com gás natural veicular. Os ensaios foram realizados em um motor Agrale modelo M90, monocilíndrico, acoplado a um alternador, tendo como carga um banco de resistências. A análise realizada contemplou o desempenho em termos de consumo de combustível, potência e emissões gasosas de óxidos de nitrogênio, dióxidos de enxofre, monóxido de carbono, entre outros gases, bem como a análise da opacidade da fumaça. Os resultados mostraram que é viável a utilização de gás natural em motores ciclo Diesel sem remoção do sistema de injeção de diesel original, representando uma considerável redução nas emissões específicas dos óxidos de nitrogênio, sem perda de potência, porém resultando em combustão incompleta em altos percentuais de substituição de combustível líquido por gasoso. De maneira geral o melhor resultado em relação à eficiência foi possível com percentual de substituição de 43,7% de diesel por gás natural, no qual o conjunto motor gerador apresentou rendimento aproximado de 33,17%. A opacidade da fumaça emitida pelo motor foi reduzida significativamente quando funcionou em modo bi-combustível tanto com diesel e gás natural como óleo de soja e gás natural.
This study aims to analyze the operation of an internal combustion engine (diesel cycle) with partial mixtures of diesel oil and natural gas, and oil vegetable soybean and natural gas. The tests were carry in an engine Agrale model M90, monocilynder, coupled to alternator, and which charged a bank of resistors load. The analyses include performance fuel consumption, power and gas emissions of nitrogen oxides, sulfur dioxides, carbon monoxide, and other gases, as well the analysis of the smoke opacity. Results showed that it is feasible to use natural gas in diesel cycle engines without removing the original diesel injection system, generating a considerable reduction in specific emissions of nitrogen oxides, without loss of Power, but resulting in incomplete combustion at high percentages replacement of liquid fuel for natural gas. Generally, the Best result for efficiency was possible with replacement percentage of 43,7% of diesel per natural gas, when the generation setting showed efficiency equal at 33,17%. The smoke opacity was reduced significantly when operated in dual fuel both diesel and natural gas as soybean oil and natural gas.
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13

Payne, Simon Daniel. "Experimental studies of diesel particulate filtration". Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610170.

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14

Nuszkowski, John. "The effects of fuel additives on diesel engine emissions during steady state and transient operation". Morgantown, W. Va. : [West Virginia University Libraries], 2008. http://hdl.handle.net/10450/5809.

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Abstract (sommario):
Thesis (Ph. D.)--West Virginia University, 2008.
Title from document title page. Document formatted into pages; contains xviii, 144 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 106-113).
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15

Sinuka, Yonwaba. "Performance testing of a diesel engine running on varying blends of jatropha oil, waste cooking oil and diesel fuel". Thesis, Cape Peninsula University of Technology, 2016. http://hdl.handle.net/20.500.11838/2436.

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Abstract (sommario):
Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016.
The high cost of fossil fuels and the fact that the world has arguably reached its peak oil production, has driven the need to seek alternative fuel sources. The main objective of the current study is to determine the performance of a laboratory-mounted diesel engine when fuelled with varying laboratory prepared biofuel and biodiesel and whether the advancement of the injection timing parameters will improve the engine power output and improve the smoke effect of these different fuel blends. The laboratory prepared biofuels used in this project range from 100% bio-fuel (BF100) to 50%, 30% and 10% biodiesel blends (BF50, BF30 and BF10, respectively). It should be noted that these blends are not commercially available, since they were blended in the laboratory specifically for these tests. The overall results of the study show that there is a distinct opportunity for using certain bio-fuel blends in specific applications as the power outputs are no more than one quarter less than that of base diesel. Concomitantly, the smoke opacity in all of the blends is lower than that of base diesel, which is a significant benefit in terms of their overall air emissions.
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16

Pianthong, Kulachate Mechanical &amp Manufacturing Engineering Faculty of Engineering UNSW. "Supersonic liquid diesel fuel jets : generation, shock wave characteristics, auto-ignition feasibilities". Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2002. http://handle.unsw.edu.au/1959.4/20325.

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It is well known that high-speed liquid jetting is one of the most powerful techniques available to cut or penetrate material. Recently, it has been conjectured that high-speed liquid jets may be beneficial in improving combustion in such applications as SCRAM jets and direct injection diesel engines. Although there are practical limitations on maximum jet velocity, a fundamental study of the characteristics of high-speed liquid fuel jets and their auto-ignition feasibility is necessary. Important benefits could be increased combustion efficiency and enhanced emission control from improved atomisation. The generation of high-speed liquid jets (water and diesel fuel) in the supersonic to hypersonic ranges by use of a vertical single stage powder gun is described. The effect of the projectile velocity and projectile mass on the jet velocity is found experimentally. Jet exit velocities from a range of different nozzle inner profiles and nozzle hardness are thoroughly examined. The characteristics and behaviour of the high-speed liquid jet and its leading bow shock wave have been studied with the aid of a shadowgraph technique. This provides a clearer picture of each stage of the generation of hypersonic liquid jets. It makes possible the study of hypersonic diesel fuel jet characteristics and their potential for auto-ignition. The fundamental processes by which a supersonic liquid jet is generated by projectile impact have been investigated. The momentum transfer from the projectile to the liquid and the shock wave reflection within the nozzle cavity are the key items of interest. A new one-dimensional analysis has been used in order to simplify this complex and difficult problem. The impact pressure obtained from the projectile was firstly derived. Then, an investigation of the intermittent pressure increase in a closed end cavity and a simple stepped, cross-sectional nozzle were carried out. The nozzle pressure and final jet velocity were estimated and compared to a previous method and to experimental results. Some interesting characteristics found in the experiments relate well to those anticipated by the analysis. The characteristics of a hypersonic diesel fuel jet and its leading edge shock wave were assessed for their potential for auto-ignition using fuel with cetane numbers from 50-100. The investigations were performed at normal ambient air and at elevated air (110 ???C) temperature. So far, there is no sign of auto-ignition that may occur because of the temperature rise of the induced shock.
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Broman, Robert, e Karl Rosenlind. "ESC-analys och studering av knack på en "Diesel Dual Fuel"-motor". Thesis, KTH, Maskinkonstruktion (Inst.), 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99784.

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Abstract (sommario):
A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated. At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NO xemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6. One issue with DDF is the high HC emission levels. HC was approximately 40 g/kWh without after-treatment and by using an oxidation catalyst it should be lowered to around 10 g/kWh (approximated based on exhaust temperatures). Engine efficiency based on fuel flows and brake torque was within 26 - 40 % at different engine speeds and torque levels, which was lower than the same engine running with only diesel. The lower efficiency can be explained with the high amount of unburned hydrocarbons. Knock and pre-ignition was a problem at high loads and at medium loads when early diesel injection was used. The knock problems with this concept were highly dependent on the intake air temperature. Methods to avoid knock were tested. One way was to move the diesel injection a couple of CAD later. This was only applicable during the first knock cycles since several knock cycles in a row heated up the combustion chamber too much. Adding (more) EGR was also a good method to avoid knock.
En encylindrig forskningsmotor har använts till att testa ett Diesel Dual Fuel-koncept (DDF) som ska fungera som en ‖retro fit‖-lösning. Med Diesel Dual Fuel menas att en dieselinsprutning används som tändkälla för att antända en homogen blandning av naturgas och luft. Emissioner och verkningsgrad har analyserats i en emissionscykel kallad European Stationary Cycle (ESC) samt problem med knack och pre-ignition har undersökts. På låg- och mellanlast användes en tidig dieselinsprutning runt 60 vevvinkelgrader före övre dödpunkt (ÖD). På dessa laster låg råemissionerna av NOx under ‖EURO 6‖-nivå (0.2 g/kWh). Över hela ESC-cykeln låg NOx på ‖EURO 5‖-nivå utan efterbehandling och med Selective Catalytic Reduction (SCR) på högre laster finns potential att uppnå ‖EURO 6‖. Ett stort problem med DDF är HC- emissionerna. Utan efterbehandling blev HC ca 40 g/kWh och med oxidationskatalysator skulle det vara möjligt att nå ca 10 g/kWh (uppskattades mha. avgastemperaturer). Motorns verkningsgrad beräknades utifrån bränsleflöden och utgående moment och låg mellan 26 - 40 % beroende på varvtal och last, vilket är lägre än för samma motor vid ren dieseldrift. Den lägre verkningsgraden förklarades med den stora mängden oförbrända kolväten. Knack och pre-ignition har visat sig vara problem med DDF-motorer på hög last samt även vid mellanlast då en tidig insprutning av dieseln användes. Det har visat sig att det här förbränningskonceptet är väldigt känsligt för luftens insugstemperatur. Metoder för att ta sig ur knack har testats i det här arbetet. Det snabbaste och enklaste har varit att flytta dieselinsprutningen några grader senare, men det fungerar endast efter ett fåtal knackcykler då förbränningsrummet värms upp mycket efter många knackcykler i rad. En annan bra metod för att gå ur knack var att tillsätta (mer) EGR.
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18

Baniasad, Mohammad Saeid. "Analysis of fuel injection rate in diesel injection systems". Thesis, Imperial College London, 1994. http://hdl.handle.net/10044/1/7439.

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19

Ng, Tze-on. "A study of sustainable fuel in public transport : the case of public light buses in Hong Kong /". Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk:8888/cgi-bin/hkuto%5Ftoc%5Fpdf?B23339743.

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20

Araujo, Jorge Paulo Dantas de. "A aplicação de planejamento estatístico multivariado no desenvolvimento de componentes do motor Diesel". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263185.

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Orientador: Roy Edward Bruns
Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: O processo de desenvolvimento de motores Diesel vem sendo cada vez mais estudado e aprimorado dentro da Indústria. A busca por ferramentas que possam reduzir o tempo de desenvolvimento e também otimizar o trabalho para atingir requisitos de desempenho, redução de consumo de combustível e limites de emissões cada vez mais restritivos é muito importante. Por esse motivo, o presente trabalho pretende contribuir com informações que podem conduzir ao conhecimento necessário para aplicação de planejamento multivariado, no processo de desenvolvimento de um motor Diesel, buscando uma diminuição no tempo para realizar esta atividade. Em uma primeira fase do trabalho, foram identificados quais os componentes (fatores) que deveriam ser estudados e também as variáveis de resposta, que no caso são consumo de óleo lubrificante e pressão de recirculação dos gases de combustão (pressão de carter). Após a definição dos componentes, foram selecionados quais os níveis dos fatores a serem estudados (no caso, mudanças geométricas dos componentes). Em seguida foi aplicada a metodologia de planejamento multivariado de experimentos (fatorial completo) para identificar qual o melhor compromisso entre as configurações estudadas visando os melhores resultados das variáveis de resposta. Ao final desta fase foi possível identificar a melhor configuração entre os componentes estudados e também um ganho substancial no tempo necessário para executar esta atividade. Já em uma segunda fase do trabalho, foi realizado um estudo verificando a influência das tolerâncias de especificação de projeto de alguns componentes considerados críticos para as mesmas respostas estudadas na fase 01 (consumo de óleo e pressão de carter). Através de um estudo fatorial fracionado foi possível identificar quais são as especificações críticas a serem controladas no processo produtivo para manter os valores de consumo de óleo e pressão de carter dentro dos padrões especificados para o motor em questão
Abstract: The Diesel engine development process has been increasingly studied and improved by industry. The search for tools that can reduce development time and also optimize the work to achieve performance requirements, fuel consumption targets and restrictive emission limits is very important. For this reason, this work aims to contribute with information that may lead to knowledge necessary for the application of multivariate planning in the development process of a Diesel engine, seeking a reduction in time to perform this activity. In the first phase of this work components (factors) that should be studied and also the response variables, which are lubricating oil consumption and pressure of combustion gas recirculation (carter pressure) have been identified. After the component definitions were made the factor levels were selected for study (geometrical changes in the components). Then multivariate statistical designs were applied (full factorial) to identify the best compromise among the levels studied in order to obtain the best results for the response variables. At the end of this phase it was possible to identify the best configurations for the components studied, which also resulted in a substantial gain in the time necessary to perform this activity. In a second phase of this work, a tolerance study was carried out on the influences of the geometrical design specifications of some components considered critical for the same responses studied in phase 1 (oil consumption and carter pressure). Through a fractional factorial study it was possible to identify the critical specifications to be controlled in the productive process to maintain the values of oil consumption and carter pressure within the defaults specified for the engine in question
Mestrado
Mecanica dos Sólidos e Projeto Mecanico
Mestre em Engenharia Automobilistica
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21

Belizário, Adenilson Cristiano. "Avaliação da confiabilidade do motor diesel com a adição de sistemas de injeção de gás na câmara de combustão". Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3151/tde-24092012-171716/.

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Visando a redução de poluentes emitidos pelos motores de combustão interna com ignição por compressão, que operam conforme o ciclo diesel, foram desenvolvidos nos últimos anos dispositivos para a operação destes motores com novos combustíveis, que além da redução de poluentes barateariam o custo de operação, devido à oportunidade de utilização de alguns combustíveis com boa disponibilidade. No presente estudo analisa-se a operação do motor diesel utilizando gás natural como combustível. Neste caso utiliza-se o óleo diesel apenas como combustível piloto, que será responsável pela ignição do segundo combustível, o gás natural. Em diversas publicações constata-se o ganho ambiental e econômico desta aplicação, porém nada é comentado em relação à alteração de índices de confiabilidade e surgimento de novos modos de falha. Neste trabalho verifica-se através de ferramentas de análise de confiabilidade, tais como a análise do tipo FMEA e Árvore de falhas, quais os principais modos de falha que serão inseridos no motor de combustão interna do tipo diesel quando este passa a operar como bi-combustível, com gás natural. Para tanto, necessita-se subdividir o motor diesel em subsistemas mostrando sua estruturação em árvores funcionais e integrando o kit diesel gás neste sistema. A partir da análise de confiabilidade verifica-se a probabilidade de ocorrência de novos modos de falha, que necessitarão da elaboração de novos planos de manutenção ou mesmo alterações no projeto do subsistema de injeção de gás natural.
In order to reduce pollutants emissions from internal combustion engines with compression bend ignition, designed to operate as the Diesel cycle, it has been developed in recent years devices for the addition of new fuels, which in addition to reducing pollutants could lower the cost of operation, due to the possibility of use of some fuels with good availability. In this case it is used only the diesel oil as the pilot flame, which is responsible for the ignition of the second fuel, the natural gas. Many publications discuss the environmental and the economic gain with the use of natural gas as fuel application, however nothing is said about the change of reliability indexes and the appearance of new failure modes in the engine. In this study through system reliability analysis tools such as Faillure Mode Effects and Analisys and Fault tree analysis it is analysed, which are the main failure modes that are inserted into the internal combustion engine when it comes to operate as dual fuel. For that analyses it is necessary to split the engine into subsystems showing its functional trees and integrating diesel gas kit in this system. New failure modes appear with greater severity than the existing in the traditional diesel engine system, leading to new design and maintenance practices. The end user, according to his need, will have one more parameter to choose whether to adopt a Diesel Gas system.
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22

Laeeq, Muhammad Nadeem. "Performance evaluation of dryer units used in diesel emission measurement systems". Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4208.

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Abstract (sommario):
Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains viii, 82 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 79-82).
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23

Bolyard, Jason D. "Evaluation of an air-to-fuel ratio derived exhaust flow rate for in-use emissions testing". Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4302.

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Abstract (sommario):
Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xi, 88 p. : ill. (some col.), col. map. Includes abstract. Includes bibliographical references (p. 59-63).
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24

Reddy, Varakala Shashidhar. "Evaluation of current and early production electronically controlled heavy-duty diesel engine emissions based on fuel property differences". Morgantown, W. Va. : [West Virginia University Libraries], 2006. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4718.

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Abstract (sommario):
Thesis (M.S.)--West Virginia University, 2006.
Title from document title page. Document formatted into pages; contains ix, 89 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 67-70).
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25

Skawinski, Grzegorz. "Fuel pump motor-drive systems for more electric aircraft". Thesis, University of Bath, 2010. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.527520.

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Abstract (sommario):
The fuel systems fitted to the current generation of civil transport aircraft are rather complicated, due to the presence of multiple tanks, pumps, valves and complex pipeline systems. During fuel transfer between the tanks, when controlling the aircraft centre of gravity or engine feed and refuel operations, a number of pumps and valves are involved resulting in complex pressure and flow interactions. In order to minimise the pressure surges during sudden system changes and flow overshoot during fuel transfer and refuelling, different motor drive system control strategies have been investigated. It is proposed that the current control method of electrically driven centrifugal-type pumps could be replaced by improved open and closed loop strategies where the flow overshoot can be minimised and pressure surges reduced. Steady-state and dynamic models of an AC induction motor drive and typical aircraft fuel system pipework components have been developed. The validation of these models has been performed using experimental data obtained from a fuel test rig constructed at the University of Bath using water as the working fluid. The simulation results have been shown to agree well with those from experimentation. In addition, the induction motor has been modelled based on its physical properties using the Finite Element Method software MEGA. The investigated fuel system has been described in linear terms and its behaviour has been identified. It is shown that the system dynamic behaviour can be controlled/improved using well established closed loop proportional-integral control. An open loop technique of simultaneous pump and valve control has been proposed and validated using experimental results, resulting in a reduction of both the transient pressure surges and flow overshoot during sudden valve closures, showing significant performance improvements. Improved closed loop control strategies for the pump drive system have also been developed in simulation. These are based on adaptive proportional-integral-derivative and fuzzy logic control strategies.
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26

Kersting, Lee. "Characterizing the Operation of a Dual-Fuel Diesel-Hydrogen Engine near the Knock Limit". Thesis, North Dakota State University, 2014. https://hdl.handle.net/10365/27572.

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Abstract (sommario):
A CAT C6.6 turbocharged diesel engine was operated in dual-fuel diesel-hydrogen mode. Hydrogen was inducted into the intake and replaced a portion of the diesel fuel. Hydrogen was added across multiple engine speeds and loads until reaching the knock limit, identified by a threshold on the rate of in-cylinder pressure rise. In-cylinder pressure and emissions data were recorded and compared to diesel-only operation. Up to 74% H2 substitution for diesel fuel was achieved. Hydrogen addition increased thermal efficiency up to 32.4%, increased peak in-cylinder pressure up to 40.0%, increased the maximum rate of pressure rise up to 281%, advanced injection timing up to 13.6?, increased NOx emissions up to 224%, and reduced CO2 emissions up to 47.6%. CO and HC emissions were not significantly affected during dual-fuel operation. At 25% load an operating condition was observed with low NOx and nearly 0 CO2 emissions, which however exhibited unstable combustion.
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27

Evans, Jason Carter. "Influence of fuel sulfur content on emissions from diesel engines equipped with oxidation catalysts". Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1594.

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Abstract (sommario):
Thesis (M.S.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains xii, 140 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 83-84).
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28

Staples, Mark Douglas. "Water consumption footprint and land requirements of alternative diesel and jet fuel". Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81130.

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Abstract (sommario):
Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, 2013.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 101-110).
The Renewable Fuels Standard 2 (RFS2) is an important component of alternative transportation fuels policy in the United States (US). By mandating the production of alternative fuels, RFS2 attempts to address a number of imperfections in the transportation fuels market: US economic vulnerability to volatile prices; security and environmental externalities; and a lack of investment in alternatives to petroleum-derived fuels. Although RFS2 aims to reduce the climate impact of transportation fuels, the policy raises a number of additional environmental concerns, including the water and land resource requirements of alternative fuel production. These factors should be considered in order to determine the overall environmental viability of alternatives to petroleum-derived transportation fuels. Middle distillate (MD) fuels, including diesel and jet fuel, are of particular interest because they currently make up almost 30% of liquid fuel consumption in the US, and alternative MD fuels could potentially satisfy 21 of the 36 billion gallons of renewable fuels mandated by RFS2 in 2022. This thesis quantifies the lifecycle blue (surface and ground) water consumption footprint of MD from conventional crude oil; Fischer-Tropsch (FT) MD from natural gas and coal; fermentation and advanced fermentation (AF) MD from biomass; and hydroprocessed esters and fatty acids (HEFA) MD and biodiesel from oilseed crops, in the US. FT and rainfed biomass-derived MD have lifecycle blue water consumption footprints between 1.4 and 18.1 lwater/lMD, comparable to conventional MD, between 4.1 and 7.5 lwater/lMD. Irrigated biomass-derived MD has a lifecycle blue water consumption footprint potentially several orders of magnitude larger, between 2.5 and 5300 lwater/lMD. Results are geospatially disaggregated, and the trade-offs between blue water consumption footprint and areal MD productivity, between 490 and 3710 lMD/ha, are quantified under assumptions of rainfed and irrigated biomass cultivation.
by Mark Douglas Staples.
S.M.in Technology and Policy
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29

Liew, ChetMun. "An investigation of hydrogen supplementation on combustion and emissions of heavy-duty diesel engines". Morgantown, W. Va. : [West Virginia University Libraries], 2010. http://hdl.handle.net/10450/11261.

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Abstract (sommario):
Thesis (M.S.)--West Virginia University, 2010.
Title from document title page. Document formatted into pages; contains xvi, 130 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 122-124).
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30

Hamedi, Mohammadreza. "Advanced thermal management of diesel aftertreatment systems". Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/7059/.

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State-of-the-art diesel exhaust gas aftertreatment systems have proved to substantially decrease vehicles’ emissions. However, their effectiveness depends on the temperature of the exhaust gas and catalysts to activate the emissions’ conversion reactions. In this research study, different strategies for thermal management of diesel aftertreatment systems were investigated to reduce vehicles’ emissions. A thermal energy storage (TES) system was developed and implemented for a light-duty diesel aftertreatment system. In this approach, the extra thermal energy of the exhaust gas during engine’s high-load conditions can be stored and reused when required, in order to maintain the emissions’ conversion reactions during a driving cycle. The results indicated that by increasing the thermal conductivity of the thermal energy storage medium and the catalyst’s substrate, the TES system can reduce the vehicle’s cumulative CO and THC emissions by 91.7% and 41.2% respectively. Active heating of the aftertreatment system was studied to provide the catalysts with the required thermal energy, in order to shorten the catalyst’s light-off period and also prevent the catalyst from light-out during a driving cycle. A pulsating electrical catalyst heating strategy and a combined electrical heating and fuel post-injection approach were developed to increase the heating efficiency while minimizing the vehicle’s emissions.
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31

Fung, Kin-lin. "A review of the effectiveness of the Government LPG Taxi Scheme as a fuel switch program for cleaner air : its implication for public acceptance and for future policies /". Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21301864.

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32

Svensson, Kenth Ingemar. "Effects of Fuel Molecular Structure and Composition on Soot Formation in Direct-Injection Spray Flames". Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd830.pdf.

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33

Clark, Lee A. "Experimental studies and systems modelling to investigate the behaviour of direct injection diesel engines". Thesis, University of Nottingham, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289480.

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34

Bomfati, Bruna Martins. "Desempenho de motor diesel com óleo vegetal de Crambe (Crambe abyssinica hochst) pré-aquecido". Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2511.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Os problemas ambientais decorrentes do uso de combustíveis fósseis têm incentivado o desenvolvimento de fontes renováveis de energia. Neste cenário, em relação à busca por possíveis substitutos ao petrodiesel, os óleos vegetais e seus derivados vêm se revelando a melhor alternativa. Porém, para os óleos vegetais serem utilizados de forma pura como combustível, adaptações devem ser feitas para reduzir sua viscosidade e minimizar a ocorrência de possíveis problemas de desempenho e de danos ao motor. Neste trabalho, foi realizado ensaio de longa duração em motor ciclo Diesel, monocilíndrico e com injeção indireta, utilizando óleo de crambe pré-aquecido a 100 °C como combustível, com o objetivo de avaliar o desempenho do motor alimentado com este óleo vegetal, em comparação ao petrodiesel, assim como observar possíveis contaminações no óleo lubrificante decorrentes da utilização do óleo de crambe. O ensaio teve duração total de 100 horas. Em intervalos de tempo predeterminados, mensurou-se o consumo e a perda de potência relativa para os combustíveis crambe e petrodiesel, e realizou-se retirada de amostra de lubrificante para análise laboratorial, sendo as primeiras avaliações no tempo zero e as subsequentes a cada 15 horas de operação do motor. Também foi calculada a eficiência térmica do conjunto motor-gerador nos dois tratamentos. O consumo de óleo de crambe foi, em média, superior ao de petrodiesel nos quatro regimes de operação do motor, sendo mais evidente a diferença entre os combustíveis nos regimes com carga. A perda de potência relativa do combustível crambe foi superior à do petrodiesel nas avaliações em que se aplicou a carga de 51% da potência nominal do motor sobre a condição de 1.800 rpm de velocidade livre de carga e para a aplicação de carga adicional de 15% sobre a condição de 51% de demanda da potência nominal do motor; porém, para a aplicação de 66% de demanda da potência nominal do motor sobre a condição de 1.800 rpm livre de carga, o combustível crambe apresentou menor perda de potência relativa. Não houve diferença na eficiência térmica do conjunto motor-gerador com os dois combustíveis, comprovando que o maior consumo de óleo de crambe compensa seu menor poder calorífico em relação ao petrodiesel. Nas análises realizadas nas amostras de lubrificante não foram observados indícios de contaminação pelo combustível e nem alterações de suas propriedades, indicando combustão adequada do óleo de crambe, entretanto, observou-se aumento acentuado da concentração de ferro. Em geral, apesar do desempenho inferior, obteve-se bons resultados com o óleo de crambe pré-aquecido como combustível, porém mais estudos são necessários para avaliar a viabilidade técnica e econômica de seu uso.
The environmental problems arising from the use of fossil fuels have encouraged the development of renewable energy sources. In this scenario, in relation to the search for possible substitutes for petrodiesel, fuels made from vegetable oils are considered an interesting alternative. However, to use pure vegetable oils as fuel, adaptations must be made to reduce the oil viscosity and minimize the occurrence of performance issues and engine damage. In this study, a long-term test was performed in a single-cylinder, indirect injection diesel engine fueled with crambe oil preheated at 100 °C, with the aim of evaluating the performance of the engine with the use of this vegetable oil as fuel, in comparison to petrodiesel, and also possible contaminations in the lubricant due to the use of crambe oil. The essay had a duration of 100 hours. At specific time intervals, consumption and relative power loss for crambe oil and petrodiesel were measured, and lubricant samples were taken for laboratory analysis. The initial evaluations were at time zero and the subsequent at each 15 hours of engine operation. Also, the thermal efficiency was calculated for both fuels. The consumption of crambe oil was, on average, higher than that of petrodiesel for the four engine operating regimes, and the difference between the fuels consumptions was more evident at load conditions. The relative power loss of crambe fuel was higher than that of petrodiesel in the evaluations in which the load of 51% of rated engine power was applied over the condition of 1,800 rpm load-free and for the application of additional load of 15% over the demand of 51% of rated engine power; however, for the application of load of 66% of rated engine power over the condition of 1,800 rpm load-free, crambe oil presented less relative power loss. There was no difference between the fuels in the thermal efficiency of the engine-generator set, proving that the higher consumption of crambe oil compensates its lower heating value in relation to petrodiesel. In the lubricant analyses, there was no evidence of contamination by the fuel and no changes in its properties, indicating adequate combustion of the crambe oil, but it was observed a marked increase in iron concentration. In general, despite the inferior performance, good results were obtained with preheated crambe oil as fuel. However, more studies are necessary to evaluate the technical and economic feasibility of its use.
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35

Chen, Pingen. "Modeling, Estimation and Control of Integrated Diesel Engine and Aftertreatment Systems". The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1416323165.

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36

Castellanelli, Márcio. "Desempenho de motor Ciclo diesel em bancada dinamométrica utilizando Biodiesel etílico de soja". Universidade Estadual do Oeste do Parana, 2006. http://tede.unioeste.br:8080/tede/handle/tede/393.

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Ahead of the forecast of scarcity of the oil, the ethyl ester (biodiesel) if has presented as an excellent alternative fuel option for engines cycle diesel. The characteristics of biodiesel are similar of diesel in terms of viscosity and the calorific power, being able to be used without adaptations in the engines. For accomplishment of this work, a motor cycle was used diesel, of direct injection with four cylinders, without adaptations. The engine was connected to a dynamometer and systems of acquisition of data auxiliary for the register of the necessary data. The performances of torque, power and brake specific fuel consumption for the following mixtures had been evaluated: B2, B5, B10, B20, B50, B75 and B100. The best registered performance was given with the B20 mixture.
Diante da previsão de escassez do petróleo, o éster etílico (biodiesel) tem se apresentado como uma excelente opção de combustível alternativo para motores ciclo diesel. As características do biodiesel são semelhantes as do diesel em termos de viscosidade e poder calorífico, podendo ser utilizado sem adaptações nos motores. Para realização deste trabalho, utilizou-se um motor ciclo diesel, de injeção direta com quatro cilindros, sem adaptações. O motor foi acoplado a um dinamômetro e sistemas de aquisição de dados auxiliares para o registro dos dados necessários. Avaliaram-se os desempenhos de torque, potência e consumo específico de combustível para as seguintes misturas: B2, B5, B10, B20, B50, B75 e B100. O melhor desempenho registrado deu-se com a mistura B20.
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37

Ahlgren, Serina. "Crop production without fossil fuel : production systems for tractor fuel and mineral nitrogen based on biomass /". Uppsala : Dept. of Energy and Technology, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200978.pdf.

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38

Oliveira, Marcelo Santana. "Estudo da influência dos acessórios no desempenho dos motores diesel turboalimentados". [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/264379.

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Orientador: Franco Giuseppe Dedini
Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: O motor Diesel é a fonte de potência primária de veículos comerciais (leves ou pesados), portanto deve-se dele conhecer, de forma abrangente, o desempenho em função da rotação e das condições de operação desejadas. A construção de um modelo teórico calibrado por medições experimentais de um motor Diesel permitirá testar e verificar a influência dos acessórios do motor em seu desempenho. O modelo deverá ser capaz de responder de forma semelhante ao sistema real, aos efeitos mecânicos e/ou às mudanças do sistema de controle do motor. Um dos aspectos fundamentais deste trabalho é a proposta de uma metodologia de testes e levantamento de parâmetros, para aspectos influentes e obtenção de valores de consumo especifico de combustível. O motor usualmente opera em condições transientes de rotações e cargas. Portanto, a potência do motor sempre deve corresponder ao funcionamento do veículo. O consumo de combustível dos veículos está diretamente relacionado com o consumo de energia que está implícito na dependência da velocidade ou no ciclo ao qual o motor for submetido. O enfoque deste trabalho está na influência dos acessórios no consumo especifico de combustível. O motor será tratado como um sistema fechado, onde os parâmetros de controle e ruídos do sistema ingressantes resultam em torque, potência e consumo específico de combustível fundamentalmente dependentes da velocidade angular do mesmo. Como a variação de carga dos acessórios altera estas relações, como o fazem e como pode ser possível absorver estas variações em prol do desempenho veicular fazem o escopo principal desta dissertação
Abstract: The Diesel engine is the primary source of power for commercial vehicles (light or heavy), so it should be known, comprehensively, the performance as a function of speed and the operating conditions that required. Construction of theoretical model calibrated to experimental measurements of a Diesel engine, will test and verify the influence of engine accessories in your performance. The model should be able to respond similarly to the real system, the mechanical effects and / or changes of the control system of the engine. One key aspect of this work is to propose a testing methodology and survey parameters, and influential aspects for obtaining values of specific fuel consumption. The engine operates usually transient speeds and loads. Therefore, the engine power must always match the operation of the vehicle. The fuel consumption of vehicles is directly related to the consumption of energy that is implicit in the velocity or cycle at which the engine is subjected. The emphasis of this work is the influence of accessories in specific fuel consumption. The engine is treated as a closed system, where the control parameters and noise entering the system results in torque, power and specific fuel consumption primarily dependent on the angular velocity of the same. As the variation in the fittings alter these relationships, as they do and how it may be possible to absorb these changes in support of vehicular performance are the main scope of this dissertation
Mestrado
Dinâmica
Mestre em Engenharia Mecânica
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39

Nilsson, Marita. "Hydrogen Generation for Fuel Cells in Auxiliary Power Systems". Doctoral thesis, KTH, Kemiteknik, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10024.

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Heavy-duty trucks are in idle operation during long periods of time, providing the vehicles with electricity via the alternator at standstill. Idling trucks contribute to large amounts of emissions and high fuel consumption as a result of the low efficiency from fuel to electricity. Auxiliary power units, which operate independently of the main engine, are promising alternatives for supplying trucks with electricity. Fuel cell-based auxiliary power units could offer high efficiencies and low noise. The hydrogen required for the fuel cell could be generated in an onboard fuel reformer using the existing truck fuel. The work presented in this thesis concerns hydrogen generation from transportation fuels by autothermal reforming focusing on the application of fuel cell auxiliary power units. Diesel and dimethyl ether have been the fuels of main focus. The work includes reactor design aspects, preparation and testing of reforming catalysts including characterization studies and evaluation of operating conditions. The thesis is a summary of five scientific papers. Major issues for succeeding with diesel reforming are fuel injection, reactant mixing and achieving fuel cell quality reformate. The results obtained in this work contribute to the continued research and development of diesel reforming catalysts and processes. A diesel reformer, designed to generate hydrogen to feed a 5 kWe polymer electrolyte fuel cell has been evaluated for autothermal reforming of commercial diesel fuel. The operational results show the feasibility of the design to generate hydrogen-rich gases from complex diesel fuel mixtures and have, together with CFD calculations, been supportive in the development of a new improved reformer design. In addition to diesel, the reforming reactor design was shown to run satisfactorily with other hydrocarbon mixtures, such as gasoline and E85. Rh-based catalysts were used in the studies and exhibit high performance during diesel reforming without coke formation on the catalyst surface. An interesting finding is that the addition of Mn to Rh catalysts appears to improve activity during diesel reforming. Therefore, Mn could be considered to be used to decrease the noble metal loading, and thereby the cost, of diesel reforming catalysts. Dimethyl ether is a potential diesel fuel alternative and has lately been considered as hydrogen carrier for fuel cells in truck auxiliary power units. The studies related to dimethyl ether have been focused on the evaluation of Pd-based catalysts and the influence of operating parameters for autothermal reforming. PdZn-based catalysts were found to be very promising for DME reforming, generating product gases with high selectivity to hydrogen and carbon dioxide. The high product selectivity is correlated to PdZn interactions, leading to decreased activity of decomposition reactions. Auxiliary power systems fueled with DME could, therefore, make possible fuel processors with very low complexity compared to diesel-fueled systems. The work presented in this thesis has enhanced our understanding of diesel and DME reforming and will serve as basis for future studies.
QC 20100804
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40

Delalibera, Hevandro Colonhese. "UTILIZAÇÃO DE ÓLEO DE GIRASSOL COMO COMBUSTÍVEL EM UNIDADE DE POTÊNCIA MONOCILINDRO CICLO DIESEL". UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2009. http://tede2.uepg.br/jspui/handle/prefix/2195.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
The many oil crises that have occurred in the past decades and the dependence of the Brazilian energy matrix on fossil fuels, as well as the environmental problems caused by their use, have pressed for advances in the search for new alternative fuels and, in a way, also made them possible. Fuels made from vegetable oils are particularly interesting, as they may substitute the diesel, the most consumed liquid fuel. The global energy matrix tends to follow in this direction until new solutions arise, despite existing problems in the functioning of the engines, particularly when using vegetable oils. For this study, two 50-hour tests were done on a direct injection, mono-cylinder micro-tractor fueled with 100 crude sunflower oil. The vegetable oil was at room temperature in the first test (E-1), and heated to an approximate temperature of 90 C in the second test (E-2). The cylinder head gasket burned after running for 50 hours in the first test. An increase of the compression ratio was observed in both tests. The carbonization of the injection system in the E-2 test was 81.5 lower than E-1. The carbonization of the intake system in the E-2 test was 51.7 lower than E-1, and the carbonization of the exhaust system in E-2 was 33.4 lower than in E-1. The carbonization in E-1 was about the same as in E-2 in the combustion chamber. Compared to diesel, the fuel consumption was 2.3 higher in E-1 and 0.7 higher E-2. The lubricant oil was contaminated with vegetable oil in both tests. Generally, E-2 was better than E-1.
As diversas crises do petróleo ocorridas nas últimas décadas, a dependência da matriz energética brasileira dos combustíveis fósseis e os problemas ambientais causados pela utilização destes têm forçado e, de certo modo, viabilizado o avanço das pesquisas na busca de combustíveis alternativos, principalmente com relação a aqueles que podem substituir o petrodiesel, como os derivados dos óleos vegetais, pois este é o combustível liquido mais consumido. Mesmo com a existência de problemas no funcionamento dos motores quando utilizados combustíveis derivados dos óleos vegetais, até o surgimento de novas soluções o cenário da matriz energética mundial tende a seguir este rumo. Neste trabalho realizaram-se dois ensaios de 50 h de duração, em um micro-trator monocilíndrico de injeção direta, utilizando 100 de óleo de girassol como combustível. No primeiro ensaio (E-1) utilizou-se óleo vegetal entrando a temperatura ambiente no sistema de injeção do motor e no segundo ensaio (E-2) aqueceu-se o óleo a uma temperatura de aproximadamente 90 C. No primeiro ensaio após 50 h foi constatada a queima da junta de cabeçote. Para os dois ensaios foi encontrado um aumento da pressão de compressão. Para a carbonização do bico injetor, a do E-2 foi 81,5 menor que a do E-1. A carbonização do sistema de admissão do E-2 foi 51,7 menor que do E-1 e a carbonização do sistema de exaustão do E-2 foi 33,4 menor que a do E-1. Para a câmara de combustão a carbonização do E-1 foi praticamente igual ao do E-2. Com relação ao consumo de combustível do E-1 e do E-2 foram respectivamente de 2,3 e 0,7 maiores que o petrodiesel. No caso do óleo lubrificante, houve contaminação por óleo vegetal combustível nos dois ensaios. No geral o E-2 mostrou-se melhor que o E-1.
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41

Ramos, Diego Berlezi. "Controlador nebuloso para motor de ignição por compressão operando com gás natural e óleo diesel". Universidade Federal de Santa Maria, 2006. http://repositorio.ufsm.br/handle/1/8607.

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A foreseeable shortage of petroleum, associated to a growing ecological conscience, demand for alternative sources of energy and more efficient and less pollutant combustion processes. Among the few pollutant fuels this work approaches the combination of natural gas, whose consumption has been increasing year to year, and diesel. It is known that the internal combustion engines convert energy with low efficiency. Based on that, this work evaluates a bi-fuel Diesel engine, power by Diesel and natural gas as means of improving its efficiency. In the engine used as a prototype, the main energy comes from the combustion of natural gas. Being the gas the main fuel, the Diesel is used only to generate the pilot explosion for the combustion process. In this way, the diesel oil is partially substituted by natural gas, increasing the combustion efficiency. Initially it was made a study on the use of the natural gas in Diesel engine through a bibliographical revision. Therefore after, they were certain the parameters that should be monitored to develop an appropriate controller. It was verified that should be appraised the engine rotation and the injection angle. The performance aimed for the action of the loop control should be the rotation of the engine. The more appropriate control techniques were investigated for the management of the natural gas injection. When analyzing the traditional techniques it observed that they present some disadvantages as the mathematical complexity, difficulties in adapt the motor to the everchanging conditions of the motor with time/temperature, limitations in the grade of controller performance and complications for practical implementation on the part of non-specialized operators. To optimize the volume of natural gas supplied to the engine an electronic manager was developed for injection of this fuel. This electronic controller is based on an adaptive fuzzy algorithm to regulate the rate of injection of fuel, which was implemented through a microcontroller. The electronic injection system controls the timing of fuel injection, so managing the volume of gas supplied to each injection cycle. The injection angle is also accurately monitored by the control system. This topology, with few alterations, can be used in any Diesel engine operating in the bifuel mode. Results of this dissertation should contribute to increase the efficiency of Diesel engine as well as reduce the consumption of fuel and emission of pollutants.
Uma previsível escassez de petróleo, aliada a uma crescente consciência ecológica, tem levado pesquisadores a procurar fontes alternativas de energia e processos de combustão mais eficientes e menos poluentes. Entre os combustíveis pouco poluentes este trabalho aborda o uso do gás natural, cujo consumo tem aumentado ano a ano. É sabido que os motores de combustão interna convertem energia com baixa eficiência. Com base nisto, este trabalho avalia um motor Diesel, bi-combustível, movido a Diesel e gás natural como forma de encontrar meios de melhorar sua eficiência. No motor usado como protótipo, nessa dissertação a energia origina-se da combustão do gás natural. Sendo o gás o combustível principal, o Diesel presta-se apenas à geração da chama piloto para o processo de combustão. Assim, substitui-se parcialmente o óleo Diesel por gás natural, aumentando o rendimento da combustão. Inicialmente procurou-se estudar o uso do gás natural em motores Diesel através de uma revisão bibliográfica. Em seguida, determinaram-se quais os parâmetros que seriam monitorados a fim de se desenvolver um controlador adequado. Verificou-se que deveriam ser avaliados a rotação do motor e o ângulo de injeção. A performance almejada para a ação da malha de controle deve ser a rotação do motor. Investigaram-se as técnicas de controle mais apropriadas para o gerenciamento da injeção de gás natural. Ao se analisarem as técnicas tradicionais observou-se que estas apresentam algumas desvantagens como a complexidade matemática, limitações na faixa de atuação do controlador, dificuldades de adaptação às condições do motor sempre variáveis com o tempo/temperatura e complicações para implementação prática por parte de operadores não-especializados. Para otimizar o volume de gás natural fornecido ao motor foi desenvolvido um gerenciador eletrônico para injeção deste combustível. Este controlador eletrônico baseia-se em um algoritmo nebuloso para regular a taxa de injeção de combustível implementado através de um microcontrolador. O sistema de injeção eletrônica controla o tempo de injeção do combustível, gerenciando assim o volume de gás fornecido a cada ciclo de injeção. O ângulo de injeção, também monitorado com precisão pelo sistema, é sincronizado com o eixo de comando de válvulas e, tomando-se como referência de posição angular o ponto morto superior do primeiro cilindro. Com poucas alterações, esta topologia, pode ser usada em qualquer motor Diesel que opere no regime bi-combustível. Os resultados desta dissertação devem contribuir para o aumento da eficiência do motor bem como redução do consumo de combustível e emissão de poluentes.
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42

Källkvist, Kurt. "Fuel Pressure Modelling in a Common-Rail Direct Injection System". Thesis, Linköpings universitet, Fordonssystem, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-70264.

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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.
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43

Zakaria, Rami. "Jet fuel spray characterisation using optical methods : an experimental study of high speed fuel injection systems in small rotary engines". Thesis, University of Warwick, 2011. http://wrap.warwick.ac.uk/54103/.

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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.
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44

Souza, Carolina Vieira de. "Perfil dos HPA prioritários na exaustão de veículo a diesel, no combustível diesel utilizado durante os ensaios de emissão veicular e no óleo lubrificante do motor". Universidade do Estado do Rio de Janeiro, 2015. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=9430.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
As concentrações na exaustão e os fatores de emissão dos hidrocarbonetos policíclicos aromáticos (HPA) prioritários de um veículo a diesel e as suas respectivas concentrações no diesel usado durante os ensaios de emissão veicular foram determinados com a finalidade de estimar a contribuição dos HPA provenientes do combustível nas emissões. Os produtos da combustão foram coletados diretamente nas emissões brutas do escapamento, utilizando um sistema de amostragem a volume constante sem diluição dos gases da exaustão. Os HPA associados ao MP foram amostrados de forma estratificada, utilizando um impactador em cascata MOUDI e filtros de fibra de vidro como substratos, e os HPA em fase gasosa foram amostrados usando cartuchos de amberlite XAD-2. A concentração dos HPA no óleo lubrificante do motor também foi monitorada ao longo do tempo até a sua troca após 12.000 km de uso. Após a extração e tratamento das amostras, a identificação e quantificação dos HPA foram realizadas, utilizando cromatografia de fase gasosa acoplada à espectrometria de massas (CG-EM) com injetor de grande volume de vaporização com a temperatura programável (PTV-LVI). Cinco variáveis do PTV-LVI foram otimizadas, utilizando planejamento de experimentos, o que permitiu obter limites de detecção menores do que 2,0 g L-1. Somente 7 dos 16 HPA prioritários foram identificados na exaustão: NAP, ACY, ACE, FLU, FEN, FLT e PYR. Os ensaios de emissão veicular foram realizados com o veículo em modo estacionário, sem aplicação de carga e com baixa velocidade de rotação do motor (1500 rpm), utilizando um diesel com menor teor de enxofre (10 mg kg-1) e com 5% v/v de biodiesel. Esses fatores possivelmente contribuíram para reduzir as emissões dos outros 9 HPA a valores abaixo dos limites de detecção do método desenvolvido. Aproximadamente 80% da massa dos HPA totais associados ao MP estavam presentes em partículas com tamanho entre 1,0 m e 56 nm, e aproximadamente 4,5% estavam presentes em partículas menores do que 56 nm. Partículas menores que 2,5 m são facilmente inaladas e depositadas no trato respiratório e na região alveolar, justificando a preocupação com relação às emissões de HPA associados a partículas provenientes da exaustão veicular de motores a diesel. Somente 5 dos 7 HPA identificados na exaustão foram detectados no diesel: NAP, ACY, FLU, FEN e PYR. A razão entre os fatores de emissão (g L-1diesel) dos HPA na exaustão e suas respectivas concentrações do diesel (g L-1) variaram de 0,01 0,02 a 0,05 0,029, dependendo do HPA. Esses valores indicam que pelo menos 95 a 99% dos HPA identificados no diesel foram destruídos e/ou transformados em outros compostos durante a combustão, e/ou foram retidos no reservatório do óleo lubrificante. Por outro lado, os HPA que tiveram maiores concentrações no diesel também apresentaram maiores fatores de emissão, o que sugere que os HPA provenientes do diesel possuem uma contribuição significativa para as emissões dos HPA totais. O perfil dos HPA prioritários no óleo lubrificante mostrou-se semelhante ao perfil dos HPA no diesel e nas emissões totais, onde o NAP, FEN e PYR foram os HPA majoritários
A diesel vehicle exhaust concentrations and emission factors of priorities polycyclic aromatic hydrocarbons (PAHs) and their respective concentrations in the diesel fuel used during the vehicle emissions testing were determined in order to estimate the fuel PAHs contribution to vehicle emissions. Combustion products are collected directly from the raw vehicle exhaust using a constant volume sampling system that does not employ exhaust products dilution. The particle-phase PAHs were sampled in stratified way using a Micro-orifice Uniforme Deposite Impactor (MOUDI) and glass fiber filter as substrates and the gas-phase PAHs were sampled using Amberlite XAD-2 cartridge. The PAHs concentrations in the engine lubricant oil were also monitored over time until its change after 12,000 km of use. After sample extractions and treatments, the PAHs identification and quantification were performed using gas chromatography coupled with mass spectrometry (GC-MS) and programmable temperature vaporization large volume injection (PTV-LVI). Five PTV parameters were optimized using statistical design experiments, which allowed to be obtained detection limits below 2.0 g L-1. Only 7 of 16 priority PAH were identified in exhaustion: NAP, ACY, ACE, FLU, FEN, FLT and PYR. The vehicle emission tests were carried out with the vehicle in stationary mode, without load, low engine speed (1500 rpm), using diesel fuel with lower sulfur (10 mg kg-1) and 5% v/v biodiesel. These factors may have contributed to reduce the other 9 PAH emissions to values below the detection limits of the method developed. Approximately 80% of the PAHs total mass associated with the particulate matter were present in particle size between 1.0 m and 56 nm and approximately 4.5% were present in particles smaller than 56 nm. Particles smaller than 2.5 m are easily inhaled and deposited in the respiratory tract and in the alveolar region, justifying the concern about PAHs emissions associated with particles from vehicle exhaust diesel engine. Only 5 of the 7 PAHs identified in exhaust were detected in diesel fuel: NAP, ACY, FLU, PHE and PYR. The ratio between the PAHs emission factors in exhaust (g L-1 diesel) and their respective concentrations in diesel fuel (g L-1) ranged from 0.01 0.02 a 0.05 0.029, depending on the PAH. These values indicate that al least 95 to 99% of the PAH identified in diesel fuel were destroyed and/or converted into other compounds during the combustion, and/or been retained in lubricant oil reservoir. On the other hand, PAHs that had higher concentration in diesel also had higher exhaust emission factors, which suggests that the PAH from diesel have a mean contribution to total PAHs emissions. The PAH priority profile in lubricant oil was similar to PAH profile in diesel and in vehicle exhaust, where the NAP, FEN and PYR were the majorities PAHs
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45

Burke, Richard D. "Investigation into the interactions between thermal management, lubrication and control systems of a diesel engine". Thesis, University of Bath, 2011. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.545325.

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Abstract (sommario):
Engine thermal and lubricant systems have only recently been a serious focus in engine design and in general remain under passive control. The introduction of active control has shown benefits in fuel consumption during the engine warm-up period, however there is a lack of rigorous calibration of these devices in conjunction with other engine systems. For these systems, benefits in fuel consumption (FC) are small and accurate measurement systems are required. Analysis of both FC and NOx emissions measurements processes was conducted and showed typical errors of 1% in FC from thermal expansion and 2% in NOx per g/kg change in absolute humidity. Correction factors were derived both empirically and from first principles to account for these disturbances. These improvements are applicable to the majority of experimental facilities and will be essential as future engine developments are expected to be achieved through small incremental steps. Using prototype hardware installed on a production 2.4L Diesel engine, methodologies for optimising the design, control and integration of these systems were demonstrated. Design of experiments (DoE) based approaches were used to model the engine behaviour under transient conditions. A subsequent optimisation procedure demonstrated a 3.2% reduction in FC during warm-up from 25°C under iso-NOx conditions. This complemented a 4% reduction from reduced oil pumping work using a variable displacement pump. A combination of classical DoE and transient testing allowed the dynamic behaviour of the engine to be captured empirically when prototype hardware is available. Furthermore, the enhancement of dynamic DoE approaches to include the thermal condition of the engine can produce models that, when combined with other available simulation packages, offer a tool for design optimisation when hardware is not available. These modelling approaches are applicable to a wide number of problems to evaluate design considerations at different stages of the engine development process. These allow the transient thermal behaviour of the engine to be captured, significantly enhancing conventional model based calibration approaches.
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46

Bueno, Andre Valente. "Analise da operação de motores diesel com misturas parciais de biodiesel". [s.n.], 2006. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263483.

Testo completo
Abstract (sommario):
Orientadores : Luiz Fernando Milanez, Jose A. Velasquez
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
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Resumo: As conseqüências da adição de biodiesel ao óleo diesel foram estudadas estabelecendo-se relações de causa e efeito entre o desempenho do motor e os processos de combustão e formação de mistura. Foram incluídos, nesta discussão, aspectos como emissões poluentes, formação de mistura, dinâmica do processo de combustão, eficiência de conversão do combustível,desempenho do motor em carga máxima e consumo específico.Utilizaram-se, sob tal propósito, técnicas tradicionalmente associadas à pesquisa e ao desenvolvimento dos motores de ciclo diesel, tais como a análise de liberação de energia, a análise exergética e ensaios dinamométricos. Devido às pequenas variações observadas nos parâmetros opcionais do motor com a introdução do biodiesel, algumas modificações nos métodos aplicados para a coleta de dados experimentais e nos modelos empregados em seu processamento se mostraram necessárias. Dentre tais ajustes, pode-se destacar a formulação de um novo modelo de análise exergética para os processos ocorrentes no cilindro e a utilização de um arranjo inédito de sistema indicador. Demonstrou-se que a adição de biodiesel em baixas concentrações favorece a conversão da exergia do combustível em trabalho no interior do cilindro, proporcionando uma elevação na eficiência de operação do motor. Para os combustíveis analisados, que compreendem a adição de até 20% de biodiesel em volume, a mistura contendo 10% desta substância ofereceu as melhores características quanto ao desempenho e ao consumo específico
Abstract: The consequences of the biodiesel blends with diesel fuel were analyzed establishing cause and effect relationships between the engine performance and the combustion and mixture preparation processes. In this investigation, aspects like pollutant emissions, mixture preparation,dynamic of the combustion process, fuel conversion efficiency, performance under full load and specific fuel consumption were included.Techniques traditionally associated with diesel engines research and development were utilized for this purpose, including heat release analysis, exergetic analysis and dynamometric bench tests. In order to account for the small effects of the biodiesel introduction on the engine operational parameters, some modifications of the methods and models applied to data acquisition and post-processment were necessary. These modifications include the formulation of a new model for the in cylinder exergetic analysis and a novel arrangement of indicator system. By using the exergetic analysis, it was demonstrated that the blending of biodiesel in low concentrations increases the conversion of fuel exergy into work within the cylinder, causing an elevation on the engine efficiency. For the analyzed fuels, which enclose up to 20% of biodiesel addition in volume, the 10% biodiesel blend has presented the best results of performance and specific fuel consumption
Doutorado
Termica e Fluidos
Doutor em Engenharia Mecânica
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47

Monsalve, Serrano Javier. "Dual-fuel compression ignition: towards clean, highly efficient combustion". Doctoral thesis, Universitat Politècnica de València, 2016. http://hdl.handle.net/10251/75109.

Testo completo
Abstract (sommario):
The more and more stringent emissions regulations, together with the greater fuel economy demanded by vehicle users, impose a clear objective to researchers and engine manufacturers: look for the maximum efficiency with the minimum pollutant emissions levels. The conventional diesel combustion is a highly efficient process, but also leads to high levels of NOx and soot emissions that require using aftertreatment systems to reduce the final levels released to the environment. Since these systems incur in higher costs of acquisition and operation of the engine, the scientific community is working on developing alternative strategies to reduce the generation of these pollutants during the combustion process itself. The literature shows that the new combustion modes based on promoting low temperatures during this process, offer high efficiency and very low NOx and soot levels simultaneously. However, after years of investigation, it can be concluded that these techniques cannot be applied in the whole engine operating range due to, among others, factors like the low control of the combustion process. In recent years, it has been demonstrated that the dual-fuel combustion technique allows to overcome this limitation thanks to the additional degree of freedom provided by the capacity of modulating the fuel reactivity depending on the engine operating conditions. This characteristic, together with the near-zero NOx and soot levels obtained with this technique, has encouraged the scientific community to deeply investigate the dual-fuel combustion. In this sense, former works confirm the advantages previously described, concluding that still exist some limitations to be tackled, as well as some margin for improving the potential of this combustion concept. The general objective of the present Doctoral Thesis is to contribute to the understanding of the dual-fuel combustion mode, with the particular aim of exploring different ways to improve its efficiency. For this purpose, it has been experimentally evaluated different options such as the modification of the engine operating parameters, specific designs of the piston geometry or the use of alternative fuels. With the aim of answering some of the questions found in the literature, the first part of each study has been dedicated to perform a detailed analysis of the influence of each particular strategy on the dual-fuel operation at low load. Later, it has been checked the ability of each option to extend the dual-fuel operating range towards higher engine loads. It is interesting to note that the analysis of some results has been supported by CFD calculations, which have allowed to understand some local phenomena occurring during the dual-fuel combustion process, which cannot be confirmed only from the experimental point of view. Finally, taking into account the knowledge acquired during the different studies performed, the last chapter of results has been devoted to evaluate the ability of the dual-fuel concept to operate over the whole engine map, as well as to identify the possible limitations that this technique presents from the technological point of view.
Las cada vez más restrictivas normativas anticontaminantes, junto con la demanda de motores con menor consumo de combustible por parte de los usuarios, imponen un claro objetivo a investigadores y fabricantes de motores: la búsqueda de la máxima eficiencia con los mínimos niveles de emisiones contaminantes. La combustión diésel convencional ofrece una alta eficiencia, pero a su vez da lugar a elevadas emisiones de NOx y hollín que requieren del uso de sistemas de postratamiento para reducir los niveles finales emitidos al ambiente. Dado que estos sistemas incurren en mayores costes de adquisición y operación del motor, la comunidad científica está trabajando en el desarrollo distintas estrategias para reducir la generación de estos contaminantes durante el propio proceso de combustión. La literatura demuestra que los nuevos modos de combustión basados en promover bajas temperaturas durante este proceso, ofrecen simultáneamente una elevada eficiencia y muy bajos niveles de NOx y hollín. Sin embargo, tras años de investigación, se puede llegar a la conclusión de que estas técnicas no pueden ser aplicadas en todo el rango de operación del motor debido a, entre otros, factores como el escaso control sobre el proceso de combustión. En los últimos años, se ha demostrado que la técnica de combustión dual-fuel permite superar esta limitación gracias al grado de libertad adicional que supone la capacidad de modular la reactividad del combustible en función de las condiciones de operación del motor. Esta característica, junto con los casi nulos niveles de NOx y hollín que proporciona, ha despertado un gran interés sobre la comunidad científica. En este sentido, trabajos precedentes confirman las ventajas que este modo de combustión ofrece, demostrando a su vez que aún existen una serie de limitaciones por abordar, así como cierto margen por explotar para mejorar el potencial de este concepto. La presente Tesis Doctoral plantea como objetivo general el contribuir a la comprensión del modo de combustión dual-fuel, y de manera particular explorar distintas vías con objeto de mejorar su eficiencia. Para ello, se han evaluado de manera experimental diferentes opciones que van desde la modificación de los parámetros de operación del motor, hasta diseños específicos de la geometría del pistón o el uso de combustibles alternativos. Tratando de responder algunas de las cuestiones encontradas en la literatura, en cada uno de los estudios se ha realizado un análisis detallado de la influencia del parámetro en cuestión sobre la operación del motor a baja carga, y a su vez se ha comprobado la capacidad de cada una de estas opciones de extender la operación del motor hacia cargas más elevadas. Cabe destacar que el análisis de ciertos resultados se ha apoyado en cálculos numéricos CFD, los cuales han permitido entender ciertos fenómenos locales que ocurren durante el proceso de combustión dual-fuel, y que no pueden ser confirmados únicamente desde el punto de vista experimental. Finalmente, teniendo en cuenta el conocimiento adquirido en los diferentes estudios realizados, el último capítulo de resultados se ha dedicado a evaluar la capacidad de operación del concepto dual-fuel en todo el rango de funcionamiento del motor, así como a identificar las posibles limitaciones que esta técnica presenta desde el punto de vista tecnológico.
Les cada vegada més restrictives normatives anticontaminants, juntament amb la demanda de motors amb menor consum de combustible per part dels usuaris, imposen un clar objectiu a investigadors i fabricants de motors: la cerca de la màxima eficiència amb els mínims nivells d'emissions contaminants. La combustió dièsel convencional ofereix una alta eficiència, però al seu torn dóna lloc a elevades emissions de NOx i sutge que requereixen de l'ús de sistemes de postractament per a reduir els nivells finals emesos a l'ambient. Aquests sistemes incorren en majors costos d'adquisició i operació del motor, per la qual cosa de forma paral·lela, la comunitat científica està treballant en el desenvolupament de diferents estratègies per a reduir la generació d'aquests contaminants durant el propi procés de combustió. La literatura demostra que les noves tècniques de combustió basades a promoure baixes temperatures durant aquest procés, ofereixen simultàniament una elevada eficiència i molt baixos nivells de NOx i sutge. No obstant açò, després d'anys de recerca, es pot arribar a la conclusió que aquestes tècniques no poden ser aplicades en tot el rang d'operació del motor a causa de, entre uns altres, factors com l'escàs control sobre el procés de combustió. En els últims anys, s'ha demostrat que la tècnica de combustió dual-fuel permet superar aquesta limitació gràcies al grau de llibertat addicional que suposa la capacitat de modular la reactivitat del combustible en funció de les condicions d'operació del motor. Aquesta característica, juntament amb els quasi nuls nivells de NOx i sutge que proporciona, ha despertat un gran interès sobre la comunitat científica. En aquest sentit, treballs precedents confirmen els avantatges que aquesta tècnica de combustió ofereix, demostrant al seu torn que encara existeixen una sèrie de limitacions per abordar, així com cert marge per explotar per a millorar el potencial d'aquest concepte. La present Tesi Doctoral planteja com a objectiu general el contribuir a la comprensió de la tècnica de combustió dual-fuel, i de manera particular explorar diferents vies a fi de millorar la seua eficiència. Per a açò, s'han avaluat de manera experimental diferents opcions que van des de la modificació dels paràmetres d'operació del motor, fins a dissenys específics de la geometria del pistó o l'ús de combustibles alternatius. Tractant de respondre algunes de les qüestions trobades en la literatura, en cadascun dels estudis s'ha realitzat una anàlisi detallada de la influència del paràmetre en qüestió sobre l'operació del motor a baixa càrrega, i al seu torn s'ha comprovat la capacitat de cadascuna d'aquestes opcions d'estendre l'operació del motor cap a càrregues més elevades. Cal destacar que l'anàlisi de certs resultats s'ha recolzat en càlculs numèrics CFD, els quals han permès entendre certs fenòmens locals que ocorren durant el procés de combustió dual-fuel, i que no poden ser confirmats únicament des del punt de vista experimental. Finalment, tenint en compte el coneixement adquirit en els diferents estudis realitzats, l'últim capítol de resultats s'ha dedicat a avaluar la capacitat d'operació del concepte dual-fuel en tot el rang de funcionament del motor, així com a identificar les possibles limitacions que aquesta tècnica presenta des del punt de vista tecnològic.
Monsalve Serrano, J. (2016). Dual-fuel compression ignition: towards clean, highly efficient combustion [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/75109
TESIS
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48

Hetreed, Christopher F. "Internal flow investigation of an aft finocyl grain configuration in a solid rocket motor". Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/46038.

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Abstract (sommario):

Cold-flow tests were conducted in mediums of air and water to investigate the internal flow field about the nozzle region of a proposed solid rocket motor (SRM) configuration that would potentially replace the current external boosters on NASA's Space Shuttle. One-eighth-scale clear acrylic models of the proposed submerged aft-dome and aft finned grain elements were constructed to simulate the aft segment of the SRM at ignition and 35 seconds into the firing sequence. Pressure, velocity, and turbulence profiles were obtained during cold air testing, while air bubbles and dye were used for flow visualization during water tunnel testing.

The flow visualization experiments indicated the presence of strong inlet vortices, alternating vortex shedding from both grain models' fins, circumferential flow in the aft-dome and around the nozzle, and recirculatory flow in the aft-dome and near an upstream portion of the 35-second grain model. Data acquired during cold air testing showed a turbulent low-velocity flow field in the aft-dome for both grain models. With respect to pressure and mean velocity virtually the entire nozzle/aft-dome region exhibited a minimal sensitivity to nozzle vectoring.


Master of Science
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49

Aksu, Cagdas. "Performance Analysis Of A Compression Ignition Internal Combustion Engine Using Superheated Ethanol Vapor". Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613255/index.pdf.

Testo completo
Abstract (sommario):
The aim of this study is to experimentally measure performance characteristics of a compression ignition (CI) internal combustion engine using superheated ethanol vapor. The engine is a 1.3L inline 4 cylinder direct injection (DI) turbocharged compression ignition (CI) engine. While the engine will be fed with superheated ethanol as homogeneous fuel-air mixture through intake manifold, the amount of diesel fuel that the engine requires to run at idle will also be supplied in order to initiate combustion. Ethanol will be superheated using a new patented double heat exchanger has been manufactured by Prof. Dr. Demir Bayka, Dr. Anil Karel and Deniz Ç
akar. The results will indicate if the suggested concept can be applicable.
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50

Belloto, Humberto Jesuino. "Análise de falhas em tubos sem costura de aço St52 utilizados em motores diesel". [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265045.

Testo completo
Abstract (sommario):
Orientador: Paulo Roberto Mei
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: O tubo de aço carbono com alto teor de manganês St52 (Norma DIN 1.0580) sem costura, com 8 mm de diâmetro externo e 3 mm de diâmetro interno, atualmente utilizado no sistema de combustível de motores eletrônicos a diesel com pressões de trabalho de até 1300 bar, apresentou problemas nos testes de durabilidade. O rompimento do tubo foi consequência das trincas internas originadas no processo de laminação, denominadas descontinuidades. O tubo de fabricação nacional, atualmente utilizado nos motores, foi comparado com um importado e os resultados dos testes encontrados determinaram qual deles teria maior vida à fadiga. São apresentados nesta dissertação o processo de fabricação do tubo com as suas vulnerabilidades, os testes de fadiga comparando as durabilidades dos tubos nacionais e importados, o efeito do processo de autofretagem e os ensaios metalográficos. Os resultados levaram a concluir que o tubo nacional não atende as solicitações de trabalho do motor e a solução imediata é a utilização do tubo importado. A recomendação para trabalhos futuros seria o estudo de melhoria no processo de laminação para diminuição do nível de descontinuidades internas tubos nacionais
Abstract: The carbon steel with high manganese in accordance with Din 1.0580 (St52) seamless 8 x 3 mm diameter has been used into fuel injection system of the electronic diesel king with pressure up to 1300 bar. This tube presented short life on durability tests due to inner cracks created during rolling process. The tube produced in Brazil and used nowadays in was compared with an imported one using a fatigue test. It is shown on this work the manufacturing tube process, the fatigue test applied to the national and imported tubes and the e effects. The results showed that the national tube does not meet the necessary requirements and the immediate solution is to use the imported one. It is recommended further used on the rolling process to reduce the internal roughness of the tubes produced in Brazil
Mestrado
Materiais e Processos de Fabricação
Mestre em Engenharia Mecânica
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