A presente dissertação trata do projeto de um motor de combustão interna de quatro tempos, ciclo Otto, destinado à categoria de competição Formula SAE, adequado ao mercado brasileiro. Uma extensa pesquisa bibliográfica e de mercado foi realizada para o direcionamento do projeto, além de análises experimentais para obtenção de dados. No estudo experimental foi utilizado um motor monocilíndrico de 300 cc de deslocamento volumétrico, arrefecido a ar, oriundo de uma motocicleta comercial atual, denominado nesta dissertação como \"motor base\". Esse motor foi instalado em uma bancada de dinamômetro e instrumentado de forma a permitir sua avaliação mecânica e termodinâmica. Estudos de desempenho, análises de combustão e emissões também foram realizados, incluindo utilização de etanol, variações da razão ar/combustível e sobrealimentação. Igualmente, foram feitos ensaios experimentais de componentes específicos utilizados no projeto. Os dados experimentais foram utilizados como parâmetros para o projeto mecânico do novo motor Formula SAE, e para a modelagem e simulação do motor base em fluidodinâmica computacional unidimensional (CFD-1D), que foi utilizada como ferramenta auxiliar do projeto. O escopo do projeto mecânico do motor foi restrito ao bloco, virabrequim e alguns componentes de integração, uma vez que todos os demais componentes foram extraídos do motor base e de outros motores presentes no mercado nacional. O motor Formula SAE foi projetado em ambiente computacional (CAD), sendo que para o projeto mecânico do bloco e virabrequim foram realizadas simulações computacionais estruturais, utilizando o método dos elementos finitos (FEA), para verificação da distribuição de tensões nos componentes projetados. O novo motor Formula SAE apresentou vantagens significativas em relação aos custos para aquisição de peças de montagem e reposição, e proporcionou flexibilidade de montagem e operação. / The present dissertation addresses the design of a 4 stroke Otto cycle internal combustion engine dedicated to Formula SAE student program and fitted to the Brazilian market. An extensive literature review and a market benchmark were performed, in order to provide guidance to the project, and experimental analysis for data acquisition. For the experimental study, a 300 cm3 single cylinder air cooled motorcycle engine has been used, taken from a motorcycle currently in production, available in Brazilian market, called in this dissertation as \"base engine\". This engine has been installed in a dynamometer test bench and instrumented in order to allow its mechanical and thermodynamic evaluation. Performance, combustion and emissions analysis were also performed, including ethanol fueling, air/fuel ratio variation and supercharging. Experimental tests with specific engine components were performed to provide necessary design data. The experimental data were used as input parameters for the mechanical design, as well as for modeling and simulation of the base engine on one-dimensional computer fluid dynamics, which was used as an auxiliary tool for this project. The scope of mechanical design of this engine was restrict to the crankcase, crankshaft and some assembly components, since all other components were taken from the base engine and other engines from the national market. The design was assisted by computer aided design (CAD). In order to verify the crankcase and crankshaft mechanical design regarding stress distribution, computational structural analysis have been performed using the finite element method (FEA). The new Formula SAE engine presented significant advantages regarding purchasing costs of parts for assembly and maintenance, and provided assembly and operation flexibility.

O processo de admissão e exaustão exercem grande influência no desempenho de um motor a combustão interna. Vários têm sido os estudos para conhecimento e detalhamento do comportamento dos parâmetros que interferem nesses processos, nas últimas décadas. Este trabalho voltou-se principalmente para o ensaio experimental de um motor do ciclo Otto utilizando etanol como combustível, avaliando o desempenho deste motor utilizando três tipos distintos de comando de válvulas e dois coletores de admissão diferentes em sua geometria, além do uso da turbo - alimentação. Numa etapa complementar fez-se uma proposta inicial de simulação numérica do comportamento hidrodinâmico do escoamento na admissão, usando técnicas de CFD, através do software CFX. Os resultados experimentais permitiram apontar o melhor arranjo não só sob o ponto de vista de torque, potência e consumo específico, como também, o que apresentou menor índice de emissões para os gases CO, CO2, NOx, HC. Criou-se um farto banco de dados para subsidiar pesquisas em motores movidos a etanol, material escasso na bibliografia aberta. A simulação numérica apresentou concordância com alguns parâmetros medidos, mas merece ainda alguns ajustes no refinamento da malha, no tempo de simulação, e no número de ciclos ensaiados, para comprovação e maior confiabilidade nos resultados obtidos. / Intake and exhaust process exercise great influence in Internal Combustion Engine performance. The behaviour of parameters that interfere in this process have been studied in the last decades. The mainly goal of this work is to test experimentally a cycle Otto engine that use ethanol as fuel, evaluating its performance using three different types of the camshaft and two intake manifold of different geometry, besides the use of the turbocharger. In addition an initial proposal numeric simulation of the hydrodynamic flow behaviour in intake, using techniques of CFD with the software CFX was made. The experimental results allowed to aim the best arrangement of the torque, specific consumption and power and what presented lower index of emissions for the gases CO, CO2, NOx, HC. A full database was created to subsidize researches in engines powered ethanol. The numeric simulation presented agreement with some measured parameters, but it still deserves some fittings in the refinement of the mesh, in the time step of simulation and in the number of rehearsed cycles, for confirmation and larger reliability in the obtained results.

Este trabalho foca no desenvolvimento de uma unidade de gerenciamento eletrônico que tem como objetivo controlar um motor de combustão interna do ciclo Otto. Essa unidade é composta por três blocos independentes, onde cada um deles é composto por um hardware e um software específico. O primeiro bloco é chamado de gerenciamento e ele é responsável por ler todos os sinais de sensores, processá-los e criar com isso alguns parâmetros de controle que são transmitidos para o bloco de sincronismo por meio de uma comunicação SPI (Synchronous Peripheral Interface). O bloco de sincronismo por sua vez recebe esses parâmetros com a intenção de controlar as válvulas injetoras e as bobinas de ignição no momento exato para manter o motor em um funcionamento perfeito. O terceiro bloco é chamado comunicação/diagnose, sendo responsável por ser a interface entre o motor e os usuários e desenvolvedores. Portanto, ele monitora algumas informações do motor e as mostram em um display, bem como possíveis falhas que possam ocorrer na utilização dele. Sendo assim, o objetivo principal desse trabalho é mostrar como essa unidade de gerenciamento eletrônico foi desenvolvida, algumas estratégias usadas para controlar o motor e alguns resultados práticos aplicando essa unidade de gerenciamento eletrônico em um motor real montado em uma plataforma de metal chamado mock-up. / This paper focuses on the development of an electronic management unit which has the objective to control an Otto cycle internal combustion engine. This unit is composed by three separated blocks where each one of these blocks is composed by one specific hardware and software. The first block is named management and it is responsible to read all the engine sensors signals, to process these signals and to create with it some parameters of control that is transferred to the synchronism block through a SPI (Synchronous Peripheral Interface) communication. The synchronism block receives these parameters in order to control the nozzles and the ignition coils in the exact moment to keep the engine running perfectly. The third block is named communication/diagnoses and it is responsible to be the interface between the engine and the drivers and developers. So it monitores some engine information and it shows this information in a display, as well some possible faults that can occur with the use of it. Therefore, the main purpose of this work is to show how this electronic control unit was developed, some strategies used to control the engine and some practical results, by applying this electronic control unit in a real engine assembled in an iron base platform, named mock-up.

Orientador: Maria Beatriz Machado Bonacelli / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociências / Made available in DSpace on 2018-08-26T07:31:59Z (GMT). No. of bitstreams: 1 Vazzoler_LuizFernandoRigacci_M.pdf: 2546389 bytes, checksum: ee62cf11666c126da5f22b48cd181f61 (MD5) Previous issue date: 2014 / Resumo: Os veículos flex fuel representam cerca de 90% da atual produção de veículos de passeio no Brasil. Historicamente a utilização de etanol como combustível automotivo remete ao início do século XX, em grande escala à década de 1970 com a conformação do Proálcool e, após um período de descrença, o etanol ressurgiu nos anos 2000 com a difusão da tecnologia flex. Este trabalho tem por objetivo central analisar a constituição da tecnologia flex fuel no país e para isso se apoia nos conceitos de paradigmas e trajetórias tecnológicas, os quais permitem compreender o processo evolutivo dos automóveis, seus sistemas de alimentação de combustível e das diversas alternativas à gasolina e ao motor de combustão interna. Ao lado disso, explora-se a história brasileira na utilização de etanol, sobretudo no período recente a partir de entrevistas e, também, em análises de dados sobre as atividades de Pesquisa, Desenvolvimento e Inovação relacionadas à tecnologia flex brasileira e seus desdobramentos, que estão representados em veículos de maior eficiência energética e com menores índices de emissão de poluentes. Por fim, realiza-se uma análise crítica do marco regulatório atual, o qual dá suporte às atividades do setor automobilístico brasileiro, e indica-se possíveis ações de indução à melhoria da tecnologia flex fuel e do uso do etanol como combustível no país. Uma das hipóteses que baseiam o trabalho de pesquisa aponta que a instabilidade relativa do mercado de etanol e a falta de competição entre as montadoras (no que toca o desenvolvimento de motores) limita a demanda tecnológica e provoca desestímulo à busca por maior eficiência ou mesmo por mudanças mais substanciais da tecnologia flex fuel desenvolvida no país. Conclui-se, dentre outros, que a atual legislação brasileira e o marco regulatório não se apresentam como indutores para alterações substantivas à iniciativa do veículo flex fuel, estimulando apenas melhorias incrementais sem tocar mais fortemente na concorrência da indústria, não explorando as oportunidades abertas pela tecnologia flex fuel / Abstract: Flex fuel vehicles represents nearly 90% of the current production of passenger cars in Brazil. Historically the use of ethanol as an automotive fuel refers to the early twentieth century, in large-scale at the 1970s with the beginning of Proálcool (Brazilian Ethanol Program), and after a disrepute period, ethanol reemerged in the 2000s with the flex fuel technology. This work¿s main objective is to analyze the constitution of flex fuel technology in Brazil, for that is based on the concepts of paradigms and technological trajectories, which allows one to understand the evolutionary movement of developing vehicles, their fuel supply systems and the pursuit of gasoline alternatives and of the internal combustion engine. Alongside this, it explores the brazilian history in ethanol use, especially in the recent period, with interviews and also based on data analysis of Research, Development and Innovation activities related to the flex fuel technology in Brazil, which makes possible the development of more energy efficient vehicles and lower pollutants emissions. Finally, it holds a critical analysis of the current brazilian legal framework, which supports the activities of the brazilian automotive industry, and specifies different ways to induce broader improvements to the use of ethanol as a fuel and the flex fuel technology in the country. One of the hypotheses that based this research points out that the relative uncertainty of the ethanol market and the lack of competition among automakers (concerning to the development of engines) constrains the technological demand and discourages the pursuit of greater efficiency or even more substantial changes on the brazilian flex fuel technology. In conclusion, among others, the current brazilian legal framework is not presented as an inducer for substantive changes on the flex fuel vehicle, encouraging only incremental improvements without leading to stronger competition in the industry, not taking advantage from the opportunities offered by flex fuel technology / Mestrado / Politica Cientifica e Tecnologica / Mestre em Política Científica e Tecnológica

Orientador: Caio Glauco Sanchez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-07T22:05:21Z (GMT). No. of bitstreams: 1 Silva_NerivaldoRodriguesda_M.pdf: 4894128 bytes, checksum: 69ef45ea8aa8986f3f2bb33a0866b270 (MD5) Previous issue date: 2006 / Resumo: Neste trabalho buscou-se desenvolver um método para a determinação da potência indicada em motores de combustão interna e medição da pressão de combustão com um osciloscópio. Para isto é necessário conhecer a curva de pressão de combustão do cilindro em função d posição angular do virabrequim e os dados da geometria do mecanismo biela-manivela. Utilizou-se a pressão de combustão do cilindro para calcular o trabalho transferido pelo gás ao pistão do motor. A pressão de combustão foi medida com um transdutor de pressão piezoelétrico. O efeito piezoelétrico é devido ao fenômeno que ocorre com o cristal de quartzo que quando submetido a uma pressão gera uma carga elétrica. Essa carga é convertida em um sinal de tensão linear e proporcional. Este sinal pode ser analisado por um osciloscópio ou ser condicionado por um sistema de aquisição de dados. Obtidos os dados, estes foram analisados através dos diagramas Log P-Log v, para verificar sua qualidade e se representavam o fenômeno físico medido. A curva da pressão do cilindro versus volume calculado foram plotadas, gerando os diagramas P-v. A área do diagrama P-v durante o tempo de compressão e expansão, que corresponde ao trabalho indicado liquido, foi determinada por integração numérica. A pressão média indicada calculada foi comparada com o valor obtido com o indicador de pressão Indiset 620 da AVL e apresentou resultado satisfatório. Os demais resultados obtidos foram analisados e comparados com os dados da revisão da literatura e apresentaram uma boa concordância. As tecnologias disponíveis para medição da pressão de combustão e os métodos para avaliação da performance são de maior importância para o estudo do processo da combustão, visando o desenvolvimento de motores com alta potência, baixo consumo de combustíveis e baixas emissões tóxicas dos gases de escapamento / Abstract: In this thesis, we were looking for a method to determinate the indicated power in a combustion engine and measurement of combustion pressure using an oscilloscope. To achieve that, it was necessary to know the curve of combustion pressure for each cylinder according to the crankshaft 's angular position and geometric data of connecting rod and crank shaft¿s mechanism. We used the cylinder¿s combustion pressure to calculate the work transferred by the gas to the engine¿s piston. The combustion pressure was measured by a piezoelectric pressure transducer. The piezoelectric effect occurs when a crystal of quartz, that under a certain pressure, generates an electrical signal. This signal is converted to a proportional and linear signal that can be analyzed by an oscilloscope or a data acquisition system. Once we obtained the data, we analyzed it thru a Log P-Log v diagram, verifying its quality and if it represents the measured physical effect. The curve of cylinder¿s pressure versus calculated area was plotted, generating the P-v diagrams. The diagram P-v area, during a certain time of compression and expansion, which correspond to the work indicated, was originated of a numerical integration. The indicated and calculated average pressure was compared to the value obtained from an AVL¿s Indiset 620 pressure indicator, showing satisfactory results. All the other results obtained were analyzed and compared to literature¿s revision data showing a good concordance. The available technologies to measure the combustion pressure and the methods to check performance, are very important to study the combustion process, aiming the development of higher power engines, lower consumption of fuel and lower toxic gas emission / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica

This thesis deals with design and realization of the onboard computer for evaluating functional parameters and status of the gas engine. Designed solution is consisted of two main parts. The first part is measuring unit whose obtains actual information on engine especially consumption of fuel, rotate per minutes and temperature of engine head. The second part of the solution is formed by pocket computer with appropriate software. The application for the pocket computer processes data from the measuring unit and from GPS receiver, which is integrated in pocket computer. Wireless bluetooth technology is used for data transfer between measuring unit and pocket computer. The application in pocket computer displays and records each of obtained and computed data.

The vehicle industry have for many years improved the design of car motors and iterated the control systems associated with it. The systems have become very complex and hard to understand because of this work process. It is today very difficult to perform evaluations of the engine's performance or components theoretically at Powertrain Engineering Sweden (PES). This thesis proposes a test method to estimate the robustness, in terms of stability margins, of the air charge throttle control loop using measurement data. Alternative test methods are also presented, for example system identification performed with MATLAB's SITB. The proposed test method superimposes a sine wave upon the control signal in a closed loop system. The control signal is measured after it is superimposed and after it have made one round trip around the loop. These two signals is regarded as sine in and sine out. The phase shift and relation in amplitude are estimated from the measurements and the robustness is presented by Bode plots. The method finds the phase shift from the time difference between the zero-crossings of the input- and output signal. The relation in amplitude is found by looking at the total sum of the absolute value sine wave. Extensive testing with different tunings of the P-part of the air charge controller shows that the proposed method correctly identifies if the systems stability margins have become larger or smaller. For nine measurements with different P-tunings it is seen that the magnitude curves stay separate throughout the whole Bode plot. It is also shown that the gain margins are decreasing for every increase in P-value. The overall results and findings in this thesis are promising and can act as a foundation for future thesis' work to come.

The data-driven models used for the design of powertrain controllers are typically based on the data obtained from steady-state experiments. However, they are only valid under stable conditions and do not provide any information on the dynamic behaviour of the system. In order to capture this behaviour, dynamic modelling techniques are intensively studied to generate alternative solutions for engine mapping and calibration problem, aiming to address the need to increase productivity (reduce development time) and to develop better models for the actual behaviour of the engine under real-world conditions. In this thesis, a dynamic modelling approach is presented undertaken for the prediction of NOx emissions for a 2.0 litre Diesel engine, based on a coupled pre-validated virtual Diesel engine model (GT- Suite ® 1-D air path model) and in-cylinder combustion model (CMCL ® Stochastic Reactor Model Engine Suite). In the context of the considered Engine Simulation Framework, GT Suite + Stochastic Reactor Model (SRM), one fundamental problem is to establish a real time stochastic simulation capability. This problem can be addressed by replacing the slow combustion chemistry solver (SRM) with an appropriate NOx surrogate model. The approach taken in this research for the development of this surrogate model was based on a combination of design of dynamic experiments run on the virtual diesel engine model (GT- Suite), with a dynamic model fitted for the parameters required as input to the SRM, with a zonal design of experiments (DoEs), using Optimal Latin Hypercubes (OLH), run on the SRM model. A response surface model was fitted on the predicted NOx from the SRM OLH DoE data. This surrogate NOx model was then used to replace the computationally expensive SRM simulation, enabling real-time simulations of transient drive cycles to be executed. The performance of the approach was validated on a simulated NEDC drive cycle, against experimental data collected for the engine case study. The capability of methodology to capture the transient trends of the system shows promising results and will be used for the development of global surrogate prediction models for engine-out emissions.

The full text will be available at the end of the embargo period: 4th Aug 2025

This thesis details a process for the development of reliable metrics that could be used to assess the quality of combustion pressure measurement data - important data used in the development of internal combustion engines. The approach that was employed in this study was a model based technique, in conjunction with a simulation environment - producing data based models from a number of strategically defined measurement points. A simulation environment was used to generate error data sets, from which models of calculated result responses were built. This data was then analysed to determine the results with the best response to error stimulation. The methodology developed allows a rapid prototyping phase where newly developed result calculations may be simulated, tested and evaluated quickly and efficiently. Adopting these newly developed processes and procedures, allowed an effective evaluation of several groups of result classifications, with respect to the major sources of error encountered in typical combustion measurement procedures. In summary, the output gained from this work was that certain result groups could be stated as having an unreliable response to error simulation and could therefore be discounted quickly. These results were clearly identifiable from the data and hence, for the given errors, alternative methods to identify the error sources are proposed within this thesis. However, other results had a predictable response to certain error stimuli, hence; it was feasible to state the possibility of using these results in data quality assessment, or at least establishing any boundaries surrounding their application for this usage. Interactions in responses were also clearly visible using the model based sensitivity analysis as proposed. The output of this work provides a solid foundation of information from which further work and investigation would be feasible, in order to achieve an ultimate goal of a full set of metrics from which combustion data quality could be accurately and objectively assessed.