This diploma thesis deals with practical measurements on the fuel system of the diesel engine system Common rail. The thesis is divided into tvo basic parts. The first part is theoretical and has the task to familiarize the reader with the history of the diesel injection until after the system Common-rail, where the principle and part of this system will be explained. The second part is focused on the possibility of practical measurement to the fuel system Common-rail on the tutorial panel. Measurement tasks for students will be created on the basis of practical measurements, including the sample assignment, and the elaboration of the form of the protocol. Verification tasks on students and the evaluation of the thesis work will be carried out in the conclusion.

Submitted by Kilvya Braga (kilvyabraga@hotmail.com) on 2018-04-24T14:36:49Z No. of bitstreams: 1 LUIZ ROBERTO ROCHA DE LUCENA - DISSERTAÇÃO (PPGEM) 2015.pdf: 2629611 bytes, checksum: 9d4b92496c709e6181c7746ee3d76d6d (MD5) / Made available in DSpace on 2018-04-24T14:36:49Z (GMT). No. of bitstreams: 1 LUIZ ROBERTO ROCHA DE LUCENA - DISSERTAÇÃO (PPGEM) 2015.pdf: 2629611 bytes, checksum: 9d4b92496c709e6181c7746ee3d76d6d (MD5) Previous issue date: 2015 / Este trabalho foi desenvolvido experimentalmente com o intuito de analisar o comportamento das emissões, da potência e do consumo do motor diesel, operando em “modo dual” com diesel/biodiesel e gás a uma taxa de substituição do diesel por gás natural da ordem de aproximadamente 85 %. Foram ensaiadas misturas de B20 a B80 com intervalos de 20%, além dos dois limites, inferior e superior (B5 e B100), do diesel comercial e do biodiesel puro respectivamente, onde foram realizados para cada condição de mistura, ensaios com rotação constante de 1800 RPM controlada eletronicamente e potências elétrica de 40, 60, 80, 100 e 120 kW, respectivamente. Todo o sistema foi monitorado por sensores de temperatura, pressão, vazão, velocidade e as emissões de NOx , NO, CO2, CO, O2, Excesso de Ar etc. foram registradas em um analisador de gases de combustão. Os dados dos ensaios foram adquiridos por meio de um sistema de aquisição de dados instalado em um PC e armazenados em mídia própria, para posterior tratamento e análise através de Tabelas e gráficos e comparação com o ensaio B5, denominado neste trabalho de padrão diesel, bem como confrontado com outros trabalhos. Ao término deste estudo podemos concluir a viabilidade do uso do gás natural em motores diesel operando no modo dual com vantagens econômicas e ambientais. / This work was developed experimentally in order to examine the performance of emissions, power and consumption of the diesel engine, operating in "dual mode" with diesel and natural gas at a fixed rate of replacement of diesel by natural gas of approximately 85%. Mixtures from B20 to B80 were tested with intervals of 20%, plus the two limits, upper and lower (B5 and B100) of commercial diesel and biodiesel respectively, which were performed for each mixture condition with constant test speed of 1,800 RPM, electronically controlled, and electric powers at 40, 60, 80, 100, and 120 kW respectively. The entire system was monitored by temperature and pressure sensors and test data were acquired by means of a data system installed on a PC and stored in adequate media, for further processing and analysis in tables and graphs and comparison with B5 test, which is called standard diesel and confronted with other studies. At the end of this research we can perceive the viability of the use of natural gas in diesel engines in dual mode with a range of economic and environmental advantages.

Made available in DSpace on 2014-12-17T15:01:52Z (GMT). No. of bitstreams: 1 ManoelRF_TESE_PARCIAL.pdf: 3699462 bytes, checksum: 4db868ae1dcdf8497e51d1aa5771684c (MD5) Previous issue date: 2011-05-16 / The industry, over the years, has been working to improve the efficiency of diesel engines. More recently, it was observed the need to reduce pollutant emissions to conform to the stringent environmental regulations. This has attached a great interest to develop researches in order to replace the petroleum-based fuels by several types of less polluting fuels, such as blends of diesel oil with vegetable oil esters and diesel fuel with vegetable oils and alcohol, emulsions, and also microemulsions. The main objective of this work was the development of microemulsion systems using nonionic surfactants that belong to the Nonylphenols ethoxylated group and Lauric ethoxylated alcohol group, ethanol/diesel blends, and diesel/biodiesel blends for use in diesel engines. First, in order to select the microemulsion systems, ternary phase diagrams of the used blends were obtained. The systems were composed by: nonionic surfactants, water as polar phase, and diesel fuel or diesel/biodiesel blends as apolar phase. The microemulsion systems and blends, which represent the studied fuels, were characterized by density, viscosity, cetane number and flash point. It was also evaluated the effect of temperature in the stability of microemulsion systems, the performance of the engine, and the emissions of carbon monoxide, nitrogen oxides, unburned hydrocarbons, and smoke for all studied blends. Tests of specific fuel consumption as a function of engine power were accomplished in a cycle diesel engine on a dynamometer bench and the emissions were evaluated using a GreenLine 8000 analyzer. The obtained results showed a slight increase in fuel consumption when microemulsion systems and diesel/biodiesel blends were burned, but it was observed a reduction in the emission of nitrogen oxides, unburned hydrocarbons, smoke index and f sulfur oxides / A ind?stria, ao longo dos anos, vem trabalhando no sentido de melhorar a efici?ncia dos motores. Mais recentemente surgiu, tamb?m, a necessidade de reduzir as emiss?es de poluentes para se adequar ?s severas leis ambientais. Isto tem despertado o interesse de desenvolver pesquisas no sentido de substituir os combust?veis derivados do petr?leo por diversos tipos de combust?veis menos poluentes, tais como: misturas de ?leo diesel com ?steres de ?leos vegetais e ?leo diesel com ?leos vegetais e ?lcool, emuls?es e microemuls?es. Este trabalho tem como objetivo desenvolver sistemas microemulsionados a partir de tensoativos n?o i?nicos dos grupos nonilfenois etoxilados e ?lcoois l?uricos etoxilados, misturas com etanol/diesel e misturas diesel/biodiesel para uso em motores diesel. Em uma primeira fase, visando selecionar os sistemas microemulsionados, foram obtidos diagramas tern?rios das misturas, sendo os sistemas compostos por: tensoativos n?o-i?nicos, ?gua como fase polar e como fase apolar o diesel e/ou misturas diesel/biodiesel. Os sistemas microemulsionados e as misturas, que representam os combust?veis estudados, foram caracterizados quanto ? massa espec?fica, a viscosidade, o ?ndice de cetano e o ponto de fulgor. Tamb?m foram avaliados o efeito da temperatura nos sistemas microemulsionados, o desempenho do motor, e as emiss?es de mon?xido de carbono, ?xidos de nitrog?nio, hidrocarbonetos n?o queimados e fuma?a de todos os sistemas. Os ensaios de consumo espec?fico e das emiss?es em fun??o da pot?ncia foram realizados em um motor de ciclo diesel em uma bancada dinamom?trica e o analisador de emiss?es GreenLine 8000. Os resultados mostraram um pequeno aumento no consumo espec?fico para os combust?veis microemulsionados, nas misturas diesel/biodiesel em rela??o ao diesel puro, por?m com uma redu??o nas emiss?es de ?xidos de nitrog?nio, hidrocarbonetos n?o queimados, ?ndice de fuma?a e ?xidos de enxofre

[pt] Este estudo foi realizado visando avaliar o desempenho de um grupo gerador na geração de energia elétrica nas áreas remotas do Brasil utilizando um combustível renovável, o óleo de dendê in natura. Foi investigado, em laboratório, o comportamento de um motogerador diesel, de 3 kVA ligado a um banco de carga composto por 16 lâmpadas de 150 kW. O desempenho do motor foi avaliado com a utilização do óleo de dendê, tendo como referência o desempenho do mesmo grupo gerador utilizando o óleo diesel. Devido à alta viscosidade do combustível escolhido, foi necessário um pré-aquecimento do mesmo para que esta propriedade fosse semelhante à do diesel. As emissões de poluentes do motor utilizando o óleo vegetal foram em média menores do que com o motor utilizando diesel. No entanto, o consumo específico de combustível do motor utilizando óleo de dendê foi maior que o consumo específico de combustível utilizando o óleo diesel. Além disso, a potência média gerada com o dendê foi a mesma que a potência média gerada com diesel. Isso indica que é possível uma substituição do óleo diesel pelo óleo de dendê in natura nas remotas localidades do país. / [en] This study was carried out aiming the performance assessment of a power generation set using a renewable fuel, the crude palm oil. It was investigated, in laboratory, the performance of a diesel generating set of 3 kVA, supplying power to a load composed of 16 light bulbs of 150kW. The performance of the engine was evaluated with the use of the crude palm oil, having as reference the performance of the same generating set using the diesel oil. Given the high viscosity of the chosen fuel, its preheating was necessary so that this property was similar to the diesel oil.The emissions of pollutants of the engine using the vegetal oil were less than that with the engine using diesel oil. However, the specific fuel consumption of the engine using crude palm oil was greater that the specific fuel consumption using the oil diesel. Moreover, the average power generated with palm oil was equal to the power generated with diesel oil. The performance of the engine was evaluated with the use of the palm oil, having as reference the performance of the same generating group using the diesel oil. The results indicate that it is possible to substitute the diesel oil by the renewable oil.

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.

The renewed interest in energy for biomass is supported by the need for different energy sources and the need to protect the environment. Recently, because of increases in crude oil prices, limited resources of fossil oil and environmental concerns there has been renewed focus on vegetable oils and animal fats to make a biodiesel fuel. What is known as biodiesel (methyl or ethyl esters) is a vegetable oil or animal fat chemically treated to replace traditional diesel fuel. Performance parameters and exhaust emissions of a diesel engine fuelled with sunflower and beef tallow ethyl esters and a blend of ethyl and methyl esters, subjected to pre-heating at two temperatures ranges, namely T55 (50 to 60ºC) and T75 (70 to 80ºC), in order to lower its viscosities, have been investigated. Tests were carried out at full load conditions in a four cylinders, four-stroke indirect injection diesel engine. Engine tests, short-term, were conducted at a range speed from 1900 to 4400 rpm. The injection timing was retarded from the manufacturer s recommended setting. The tests were carried out using the same engine and test procedures so that comparative assessments may be made. The tests data were used for evaluating the brake power, exhaust gas temperatures, specific fuel consumption and gaseous emissions. The analysis of the results determined that the level of pre-heating have influence on the performance for used esters. The tests performed at T55 showed the best values of torque (N.m), power (kW) and specific fuel consumption (g.kW-1.h-1) that the tests performed at T75. The bests experiments results were obtained with sunflower ethyl ester and the blend containing 50,0% sunflower ethyl ester and 50,0% beef tallow methyl ester, at -2º BTDC and T55 temperature range. The findings showed that, by using biodiesel, harmful emissions (CO, HC and NOx) can be reduced to some extent of B2 by adjusting the injection pump timing properly and pre-heating of fuel. / O renovado interesse por energia da biomassa é apoiado na necessidade de fontes alternativas de energia e de proteção ambiental. Recentemente, devido ao aumento dos preços do óleo cru, a limitação de seus recursos e as questões relacionadas ao ambiente, um renovado foco passou a existir sobre os óleos vegetais e gorduras animais para produção de um biodiesel combustível. O que é conhecido como biodiesel (éster metílico ou etílico) é um óleo vegetal ou gordura animal tratado quimicamente para substituir o combustível diesel tradicional. Parâmetros de desempenho e emissões de exaustão foram investigados para um motor diesel alimentado com ésteres etílicos de óleo de girassol e de sebo bovino e por uma mistura composta pelo éster etílico de óleo de girassol e pelo metílico de sebo bovino numa proporção volumétrica igual (50,0%+50,0%). Os ésteres estavam sujeitos ao pré-aquecimento segundo duas faixas de temperaturas, chamadas de T55 (50 a 60ºC) e T75 (70 a 80ºC), como forma de redução da viscosidade. Os testes foram conduzidos sob condição de carga máxima em um motor diesel de quatro cilindros, quatro tempos e de injeção indireta de combustível. Os ensaios de curta duração foram efetuados em uma faixa de rotações compreendida entre 1900 e 4400 rpm. O ponto de avanço de injeção foi atrasado em relação ao ponto original recomendado pelo fabricante. Os testes foram conduzidos utilizando o mesmo motor e os mesmos procedimentos de testes para permitir a comparação dos valores obtidos. Nos ensaios foram obtidos os valores de potência, torque, consumo específico de combustível e gases de exaustão. A análise dos resultados indica que o nível de pré-aquecimento tem influência sobre o desempenho dos ésteres utilizados. Os ensaios conduzidos à T55 mostraram melhores valores para torque (N.m), potência (kW) e consumo específico de combustível (g.kW-1.h-1) que os testes executados à T75. Os melhores resultados do experimento foram obtidos pelo éster etílico de girassol e pela mistura contendo 50,0% de éster etílico de girassol e 50% de éster metílico de sebo bovino, sob 2º (P2) de atraso no ponto de injeção e aquecidos na faixa de temperaturas de T55. Os resultados indicam que, pelo uso do biodiesel, as emissões prejudiciais (CO, HC e NOx) podem ser reduzidas aos mesmos níveis do B2 através do ajuste apropriado do ponto de avanço da injeção e o pré-aquecimento do combustível.

The concepts of engine downsizing and down-speeding offer reductions in CO2 emissions from passenger cars. These reductions are achieved by reducing pumping and friction losses at part-load operation. Conventionally, rated torque and power for downsized units are recovered by means of turbocharging. The transient response of such engines is, however, affected by the static and dynamic characteristics of the turbo-machinery. Recent advances in engine simulation and control tools have been employed for the purpose of the research reported in this thesis to identify and verify possible air-path enhancements. A systematic method for evaluating various turbocharger assistance concepts is proposed and discussed in this thesis. To ensure a fair comparison of selected candidate systems, an easily reconfigurable controller providing a close-to-optimal operation, while satisfying physical limits, is formulated. This controller is based on the Model Predictive Control framework and uses a linearised mean value model to optimise the predicted behaviour of the engine. Initially, the controller was applied to a 1D simulation model of a conventional light-duty Diesel engine, for which the desired closed-loop features were verified. This procedure was subsequently applied to various air-path enhancement systems. In this thesis, a turbocharger electric assistance and various concepts based on compressed gas injection were considered. The capability of these systems to improve engine response during third gear tip-in manoeuvre was quantified. This investigation was also complemented with a parametric study of how effectively each of the considered methods used its available resources. As a result, injecting compressed gas into the exhaust manifold was identified as an effective method, which to date has attracted limited attention from engine research community. The effectiveness of the exhaust manifold assistance was experimentally verified on a light-duty Diesel engine. The sensitivity of the improvements to compressed gas supply parameters was also investigated. This led to the development of the BREES system: a low component count, compressed gas based system for reducing turbo-lag. It was shown that during braking manoeuvres a tank can be charged to the level sufficient for a subsequent boost assistance event. Such a functionality was implemented with a very limited set of additional components and only minor changes to the standard engine control.

No description available.

Orientador: Alberto Adade Filho / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T17:00:41Z (GMT). No. of bitstreams: 1 Torrigo_Eduardo_M.pdf: 4407726 bytes, checksum: 787c00ebb1a9971b6c1cf1d6b78d7180 (MD5) Previous issue date: 2011 / Resumo: Tendo em vista a melhora da qualidade do ar, são impostos limites de emissões de poluentes aos motores diesel, obrigando a busca de soluções capazes de reduzir essas emissões. O motor movido a diesel tem como emissão crítica de poluentes os óxidos de nitrogênio e a emissão de material particulado. Toda a química de formação de poluentes está interligada ao processo de combustão, que é diretamente influenciado pelas concentrações de reagentes admitidos no cilindro. A recirculação controlada de gases de escape para a admissão é uma técnica de redução de emissões de óxidos de nitrogênio comumente aplicada ao motor diesel. Motores instalados em veículos estão sujeitos a variações de regime de operação devido à dinâmica veicular, como por exemplo acelerações ou troca de marchas, que produzem alterações na pressão e no fluxo de gases modificando a proporção da mistura de ar limpo e recirculante admitida no cilindro do motor. O sistema de controle dos gases, portanto, é elemento importante no controle das emissões de poluentes. O objeto deste estudo é o projeto e análise de configurações de controle aplicadas ao sistema de ar de um motor diesel. Foram escolhidos os controladores PID descentralizado, atualmente utilizado na indústria, e o regulador linear quadrático com integrador. Para aumentar a representatividade do estudo, é identificado um conjunto de modelos dinâmicos entrada-saída do sistema de ar de um motor diesel para uso no projeto e na simulação dos sistemas de controle. Por intermédio de uma mesma abordagem algorítmica de projeto e utilizando uma função custo de controle ótimo, projetos dessas diferentes alternativas de controle são efetuados e o desempenho dos controladores e suas características são comparados. Os resultados indicam que a configuração multivariável reduz interferências no controle devido ao acoplamento entre as variáveis e também o tempo necessário à acomodação do sistema de ar, mas tem implicações práticas a serem consideradas. Essas características de resposta e desempenho têm impacto na emissão de poluentes, como elaborado no trabalho. Os aspectos práticos de implementação e de confiabilidade também são discutidos / Abstract: Diesel engine technology has been driven by stringent regulation. To fulfill this demand emission control systems are constantly improving The diesel-powered engines are major pollutant sources of nitrogen oxides and particulate matter. All the chemistry of pollutants formation is linked to the combustion, which is directly influenced by concentrations of reagents admitted to the cylinder. The controlled recirculation of exhaust gases to intake chamber is a commonly applied technique to reduce nitrogen oxides emissions of the diesel engines. Engines installed in vehicles are subject to variations in operation due to the vehicle dynamics, such as accelerations or gear shifting, that produce changes in pressures and gases flow, affecting the clean air and recirculated gas mixture proportion admitted to the engine cylinder. The control of the gases therefore plays an important role in pollutant emissions reduction. The goal of this study is the design and analysis of decentralized and multivariable control systems applied to the air management of a diesel engine. To enhance the study representativeness, it is identified a set of dynamic models of the air system of a diesel engine to use in design and of control simulation. The optimal control condition is determined by cost functions reduction. Two different control structure and tuning alternatives are studied and the controller performance and their characteristics are compared. The results indicate that the multivariable proposal (LQR controller with integral action) reduces interferences in the control due to the coupling between variables, it also reduces the settling time of all controlled variables, however the implementation aspects must be evaluated more deeply. The impacts on emissions caused by controller response characteristics and performance are discussed in the work. Reliability and implementation aspects are also discussed / Mestrado / Eletrônica / Mestre em Engenharia Automobilistica

In an effort to reduce harmful pollutants emitted by medium and heavy duty diesel engines, stringent emission regulations have been imposed by the Environmental Protection Agency (EPA) and the California Air Resources Board (CARB). Effective aftertreatment thermal management is critical for controlling tail pipe outlevels of NOx and soot, while improved fuel efficiency is also necessary to meet greenhouse gas emissions standards and customer expectations. Engine manufacturers have developed and implemented several engine and non-engine based techniques for emission reduction, a few examples being: exhaust gas recirculation (EGR), use of delayed in-cylinder injections, exhaust throttling, electric heaters and hydrocarbon dosers. This work elaborates the use of variable valve actuation strategies for improved aftertreatment system (ATS) thermal management of a modern medium-duty diesel engine while presenting opportunities for simplification of engine air handling architecture.<div><br></div><div>Experimental results at curb idle demonstrate that exhaust valve profile modulation enables effective ATS warm-up without requiring exhaust manifold pressure (EMP) control. Early exhaust valve opening with internal exhaust gas recirculation (EEVO+iEGR) resulted in 8% lower fuel consumption and reduction in engine out emissions. Late exhaust valve opening with internal EGR in the absence of EMP control was able to reach exhaust temperature of 287^◦C, without a penalty in fuel consumption or emissions compared to conventional thermal management. LEVO combined with EMP control could reach turbine outlet temperature of nearly 460^◦C at curb idle.<br></div><div><br></div><div>LEVO was studied at higher speeds and loads to assess thermal management benefits of LEVO in the absence of EMP control, with an observation that LEVO can maintain desirable thermal management performance up to certain speed/load conditions, and reduction in exhaust flow rate is observed at higher loads due to the inability of LEVO to compensate for loss of boost associated with absence of EMP control.<br></div><div><br></div><div>Cylinder deactivation (CDA) combined with additional valvetrain flexibility results in low emission, fuel-efficient solutions to maintain temperatures of a warmed-up ATS. Late intake valve closing, internal EGR and early exhaust valve opening were studied with both three cylinder and two cylinder operation. Some of these strategies showed additional benefits such as ability to use earlier injections, elimination of external EGR and operation in the absence of exhaust manifold pressure control. Three cylinder operation with LIVC and iEGR is capable of reaching exhaust temperatures in excess of 230^◦C with atleast 9% lower fuel consumption than three cylinder operation without VVA. Three cylinder operation with early exhaust valve opening resulted in exhaust temperature of nearly 340^◦C, suitable for extended idling operation. Two cylinder operation with and without the use of valve train flexibility also resulted in turbine outlet temperature relevant for extended idling (and low load operation), while reducing fuel consumption by 40% compared to the conventional thermal management strategy.<br></div><div><br></div><div>A study comparing the relative merits of internal EGR via reinduction and negative valve overlap (NVO) is presented in order to assess trade-offs between fuel efficient stay-warm operation and engine out emissions. This study develops an understanding of the optimal valve profiles for achieving reinduction/NVO and presents VVA strategies that are not cylinder deactivation based for fuel efficient stay-warm operation. Internal EGR via reinduction is demonstrated to be a more fuel efficient strategy for ATS stay-warm. An analysis of in-cylinder content shows that NOx emissions are more strongly affected by in-cylinder O2 content than by method of internal EGR.<br></div>