Orientador: Sérgio Tonini Button / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T21:08:57Z (GMT). No. of bitstreams: 1 Possamai_Lisiane_M.pdf: 4008102 bytes, checksum: b6e9b8d71cd5acc093a6d8f5074751db (MD5) Previous issue date: 2011 / Resumo: Este trabalho tem como objetivo principal avaliar se a determinação da concentração de metais em óleo lubrificante por ICP-OES (Espectrometria de Emissão Ótica com Plasma Indutivamente Acoplado, do inglês Inductively Coupled Plasma Optical Emission Spectroscopy), é capaz de auxiliar no diagnóstico de eventuais falhas por desgaste em motores Diesel não detectadas no ensaio funcional de produção (amaciamento). O tratamento dos dados foi realizado empregando-se métodos estatísticos. Parâmetros como carga de trabalho, rotação, pressões, temperaturas, assim como a severidade do desgaste, podem não ser suficientes para manifestar a falha durante o tempo de exposição do motor ao ensaio, postergando a sua ocorrência para a planta do cliente (montadora) ou para o campo. O conhecimento da concentração dos elementos metálicos em óleo lubrificante é útil para a avaliação de desgastes de componentes específicos de motores permitindo uma intervenção preventiva a fim de evitar falhas catastróficas. A partir da análise dos dados históricos disponíveis na empresa definiu-se o conceito de assinatura de desgaste e buscou-se conhecer o comportamento dos resultados das análises de óleo, quando se constatou variabilidade significativa dos valores que pode ser explicada por erros sistêmicos e aleatórios. A validação da técnica por ICP-OES para detecção de desgaste prematuro em motores foi realizada a partir da reprodução do modo de falha mais comumente encontrado em motores de combustão interna, que é o engripamento de biela. Simulou-se a contaminação do sistema tribológico casquilho, moente e óleo, considerando-se o agente de contaminação externa proveniente da região de fechamento da capa da biela. Conforme esperado, os motores foram aprovados dentro dos parâmetros de controle existentes. Após a desmontagem dos motores evidenciouse que o sistema tribológico fora seriamente comprometido por desgaste do casquilho (bronzina), que apresenta um revestimento superficial de alumínio e estanho. Na análise univariada de metais dissolvidos no óleo lubrificante identificou-se a presença de estanho, o que não é esperado encontrar neste modelo de motor. No tratamento multivariado foi possível analisar a correlação dos metais dissolvidos no óleo cuja análise estatística possibilitou distinguir motores conformes de não conformes de forma quantitativa e objetiva. Desta forma, conclui-se que o método de análise de metais dissolvidos em óleo lubrificante por ICP-OES é eficaz, se mostrando sensível na detecção de desgaste do sistema casquilho-moente / Abstract: The main goal of this study is to evaluate if the determination of metal concentration in lubricant oil by ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy) is capable to help on eventual wear failures diagnosis on Diesel engines that are not detected in the production test cycle (running in). The data processing was done using statistical methods. Parameters like load, engine speed, pressures, temperatures, as well wear severity, cannot be enough to show the failure during the engine test time postponing the failure occurrence to OEM or field. The metallic elements concentration knowledge in lubricant oil is useful to evaluate specific engines parts wear allowing a preventive action in order to avoid catastrophic failures. Starting from the historic data analysis available in the company it was defined the concept of wear signature looking for oil analysis results behavior understanding, where it was noticed significant values variability due to random and systemic errors. The ICP-OES validation for premature wearing detection on engines was done starting from most usual failure mode found on internal combustion engines that is connecting rod scuffing. The tribological system bearing, crankshaft pin and oil was set to simulate a failure by an external contamination coming from the connecting rod cracked assembly area. As expected, the engines were approved according to current controls. After engine disassembly it was noticed that the tribological system was heavy damaged due to bearing wear whose surface layer composition is made of aluminum and tin. In the univariate oil analysis of metals dissolved it was detected tin which is not expected to be finding in this engine model. In the multivariate data processing it was possible to analyze the dissolved metals correlation whose statistical analysis make possible to distinguish conforming engines from non-conforming engines in a quantitative and objective way. So it is possible to conclude that the ICP-OES method to analyze dissolved metal in oil is effective showing sensibility to detect wear between crankshaft pin and connecting rod bearing system / Mestrado / Projetos / Mestre em Engenharia Automobilistica

Orientador: Irany de Andrade Azevedo / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-18T23:07:14Z (GMT). No. of bitstreams: 1 Martins_TalesRibeiro_M.pdf: 3049449 bytes, checksum: 5570470f66bfb2bcc9e6231e02e25dd5 (MD5) Previous issue date: 2011 / Resumo: As empresas do ramo automotivo costumam empregar testes de durabilidade para confirmar o atendimento das especificações estabelecidas em projeto, já que existe a necessidade de garantia da qualidade do produto a ser comercializado. No trabalho é realizada uma estimativa da confiabilidade de um motor diesel na fase de desenvolvimento com o uso de uma ferramenta de gerenciamento de crescimento da confiabilidade. São apresentados os conceitos essenciais para a estimação do valor da confiabilidade e de seu crescimento, o processo típico de desenvolvimento do produto e seu ciclo de vida no mercado. É descrito o procedimento atualmente realizado por uma empresa do ramo automotivo com grande participação no mercado brasileiro e internacional, são descritos os testes de validação usados, e é apresentada uma proposta de melhoria no modelo atual. A proposta consiste em classificar as falhas encontradas no decorrer dos testes, identificar os sistemas mais suscetíveis à falha nas condições de uso previstas, e utilizar uma ferramenta de software baseada no modelo AMSAA-CROW para estimar o crescimento da confiabilidade, com base no MTBF e no parâmetro de forma â. A curva de crescimento da confiabilidade gerada indica a evolução do desenvolvimento até o objetivo a ser atingido. Com os dados de falhas identificadas no decorrer do desenvolvimento é plotada a curva de evolução da confiabilidade ao longo da fase de desenvolvimento. O modelo proposto possibilita a verificação, ao longo do período de desenvolvimento do produto, da eficácia das ações corretivas. Permite, ainda, determinar se a confiabilidade especificada para o produto já foi atingida e se a quantidade de recursos alocados ao desenvolvimento é suficiente. Os dados obtidos ao longo do processo permitem a formação de um banco de dados padronizado a ser usado em outros desenvolvimentos / Abstract: Automotive companies involved in diesel engines development often use durability tests to confirm the achievement of the specifications established in a project, aiming to build the desired level of quality in a product being marketed. In this work a software based tool is used to estimate the reliability growth evolution trough engine development phase. The essential concepts for the estimation of the value of reliability and of its growth, the typical process of product development and its life cycle in the market are considered. A procedure currently performed by an automotive company with significant market share in Brazil and abroad and the validation tests it uses is described. A new procedure is proposed aiming to improve the current model through development time reduction and early failures identification and correction. It consists in classifying the failures found during testing, identifying the systems more susceptible to failure in the conditions specified during operation, and applying a software tool based on the Crow-AMSAA model to estimate the reliability growth, based on the MTBF and the shape parameter â. The reliability growth curve is generated using the desired goal at the end of development, predicting the evolution of reliability throughout the development phase. The proposed model enables evaluation of the effectiveness of corrective actions; it is a tool that can be used to judge if the reliability goal has been reached and if the resources allocated to development are enough. The data obtained during the process allow the formation of a standardized database to be used in future developments / Mestrado / Projetos / Mestre em Engenharia Automobilistica

Orientador: Luiz Carlos Sandoval Góes / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-19T02:42:23Z (GMT). No. of bitstreams: 1 Silva_RobertoCarlosdeCastro_M.pdf: 3523448 bytes, checksum: 056edbb15555679526f8d88b82ca288c (MD5) Previous issue date: 2011 / Resumo: Neste trabalho construiu-se e verificou-se um modelo matemático capaz de realizar o cálculo da rotação do eixo do turbocompressor aplicado a um motor Diesel, para futura implementação de uma função de software no programa da unidade de comando do motor, de forma a permitir a criação de estratégias de proteção contra sobre rotação do eixo do turbocompressor. O modelo foi construído com utilização de modelagem de fenômenos físicos que ocorrem em algumas partes do motor, junto com tabelas obtidas através de testes empíricos do motor. O modelo foi criado de modo a aproveitar os sensores atualmente disponíveis no motor de série, utilizados pelo sistema de injeção eletrônica. O parâmetro de vazão de ar admitido, calculado pela unidade de controle do sistema de injeção também foi aproveitado. Após a criação do modelo, este foi verificado inicialmente simulando-se variações nas entradas (quantidade injetada de combustível e acionamento da válvula EGR) e analisando-se a reação ocorrida na saída do modelo (rotação do eixo do turbocompressor). Foram realizadas medições em um banco de testes para o levantamento do mapa de temperatura do coletor de escape em condição estacionária. Para a verificação do modelo em um caso real, foram coletados dados de diversos parâmetros de funcionamento de um motor diesel instalado em um veículo de testes da MWM International. Os parâmetros de entrada coletados foram inseridos no modelo e o valor de rotação medido confrontado com o valor calculado. Ajustes nos submodelos foram necessários para a estimação dos parâmetros do modelo através da minimização do erro encontrado. O erro encontrado diminuiu sensivelmente, porém ainda se manteve alto para ser considerado como uma informação confiável para a implementação no software da unidade de comando do motor / Abstract: In this work, it was intended to create a model capable to calculate the turbocharger shaft speed of a Diesel engine, for future implementation of an algorithm in the engine's Electronic Control Unit software, as a protection strategy against turbocharger shaft overspeed. The model was built using physical phenomenon modeling from some parts of the engine, among tables obtained by empiric tests of the engine. The model was created in order to use current sensors available in the series production engine, which is used by electronic fuel injection system. The intake air flow parameter, already calculated by ECU, was also used. After the model creation, it was verified simulating input variation (fuel injected quantity and EGR valve command) and analyzing the model output (turbocharger shaft speed). Measurements in bench test were performed in order to create an exhaust manifold temperature map in steady condition. In order to check the model in a real case, several operating parameter data were collected from a Diesel engine installed in a test vehicle from MWM International. The acquired data was inserted in the model and the turbocharger shaft speed was crosschecked against the calculated value. Adjustments in submodels were necessary to parameter estimation through minimizing of error found. The error decreased significantly, however it remained too high to be considered a reliable information for implementation in the controller's software / Mestrado / Eletrônica / Mestre em Engenharia Automobilistica

Les normes européennes EURO 5 / EURO 6 de réduction des émissions polluantes des véhicules automobile sont de plus en plus sévères. La boucle de recirculation des gaz d’échappement, dite boucle EGR (Exhaust Gas Recirculation), est une solution de dépollution à la source car elle réduit les quantités émises d’oxydes d’azote et de particules de suie. Ce contexte entraîne une utilisation plus intensive de la boucle EGR, d’où une augmentation de son encrassement. Assurer la fiabilité de cette boucle est un enjeu important pour les constructeurs automobiles. Un montage expérimental dont on contrôle les conditions opératoires a été conçu pour recréer les dépôts observés dans l'échangeur EGR d'un moteur Diesel. Il permet de déterminer les paramètres pilotant la formation et l’évolution du dépôt d'encrassement, via une mesure de sa masse, une analyse de sa composition chimique et un suivi des transferts thermiques (thermocouples, caméra infra rouge) dans l’échangeur au cours du temps. / The EURO 5 and EURO 6 European norms on the vehicle pollutant emission reduction are stricter than the previous. The Exhaust Gas Recirculation system, also called as EGR system, is a solution for the remediation at source, because it reduces the quantity of emitted nitrogen oxides and soot particles. The resulting intensive use of the EGR system increases the fouling in the involved heat exchanger. Ensuring the reliability of the EGR system is an important challenge for car manufacturers. An experimental set-up, with controlled operating conditions, has been built to recreate the deposit observed in the EGR heat-exchanger of Diesel engines. It enables to determine the parameters driving the fouling deposit formation and evolution, via a weight measurement, a chemical composition analysis and a follow-up of the thermal transfer (thermocouples, IR camera) in the heat-exchanger over the time.

Ce travail présente un modèle orienté vers le développement d’un simulateur pour un moteur diesel marin. Dans le but d’avoir un simulateur qui répond aux besoins du moteur étudié au niveau de l’efficacité, la rapidité, et la prise en considération des défauts, le modèle étudié est basé sur des modélisations physiques, semi physique, empirique, mathématique et thermodynamique. Le modèle du moteur est divisé en plusieurs sous-modèles chacun présente un système réel, ces systèmes sont : le refroidissement, la lubrification, l’air, l’injection, la combustion et les émissions. Les sous-modèles et les caractéristiques dynamiques du chaque bloc sont conçus en respectant les équations principales du fonctionnement du moteur ainsi que les données expérimentales collectées du banc d’essai du moteur marin diesel fabriqué par la société SIMB sous la référence 6M26SRP1. Ce modèle a été implémenté sur Matlab/Simulink, et la simulation calcule les variables suivantes : pression, température, efficacité, échange de chaleur, angle de vilebrequin, débit du fuel et émissions, et ceci dans les différentes sous-blocs. Le simulateur est utilisé pour montrer la performance du moteur lors de l’occurrence des défauts et peut aider dans l’application des stratégies d’optimisation pour le dimensionnement, de diagnostic et de pronostic. / This work presents a simulator model of a marine diesel engine based on physical, semi-physical, mathematical and thermodynamic equations, allowing fast predictive simulations. The whole engine system is divided into several functional blocs: cooling, lubrication, air, injection, combustion and emissions. The sub-models and dynamic characteristics of individual blocs are established according to engine working principles equations and experimental data collected from a marine diesel engine test bench for SIMB Company under the reference 6M26SRP1. The overall engine system dynamics is expressed as a set of simultaneous algebraic and differential equations using sub-blocs and S-Functions of Matlab/Simulink. The simulation of this model, implemented on Matlab/Simulink has been validated and can be used to obtain engine performance, pressure, temperature, efficiency, heat release, crank angle, fuel rate, emissions at different sub-blocs. The simulator is used to study the engine performance in faulty conditions, and can be used also to assist marine engineers in FDI (fault detection and isolation) as well as designers to predict the behavior of the cooling system, lubrication system, injection system, combustion, emissions, in order to optimize the dimensions of different components.

La croissance mondiale, économique et industrielle, ainsi que la rapide progression démographique des populations, ont fait augmenter la demande en énergie fossile. Ces dernières années, beaucoup de recherches ont été orientées vers de nouvelles ressources énergétiques qui peuvent remplacer les carburants fossiles conventionnels. Les biocarburants sont des carburants écologiques renouvelables, obtenus grâce à la transformation des matières grasses animales et végétales. Ils sont classés en tant que ressource idéale, non-toxique et renouvelable, substituant avantageusement le Diesel conventionnel. Dans cette optique, nous nous sommes intéressés à la production des biocarburants à partir d’une source végétale, non alimentaire, très abondante dans le bassin méditerranéen, en l’occurrence le pistachier lentisque, par deux procédés, l’un est chimique appelé transestérification et l’autre est thermochimique, la solvolyse. Les caractérisations des biocarburants conformément aux normes en vigueur, ont montré que les propriétés physico-chimiques sont comparables à celles du Diesel conventionnel. Un moteur Diesel monocylindre refroidi à l'air, a été utilisé pour évaluer les caractéristiques de la combustion de ces biocarburants, à 1500 tr/min, sous diverses conditions de charges du moteur. Les caractéristiques de la combustion (pression du cylindre, délai d’auto-inflammation, taux de dégagement de chaleur et durée de combustion) des biocarburants obtenus, sont comparées à celles du Diesel conventionnel. / The world economic and industrial growths, as well as the demographic rapid progression, have increased the fossil energy demand. These last years, much of researches were directed towards new energy resources which can replace the conventional fossil fuels. The biofuels are renewable ecological fuels derived from biomass; they are classified as an ideal resource, non-toxic and renewable component with respect to the conventional Diesel. In this context, we were firstly interested to the production of the biofuels starting from a non-edible vegetable source widely available in the Mediterranean basin which is the Pistacia Lentiscus using two processes. The first one is a chemical method named “transesterification” and the second one is a thermochemical procedure called “solvolysis”. The biofuels physicochemical properties, measured via standard methods, are similar to those of Diesel fuel. A single cylinder, naturally aspirated DI Diesel engine is operated at 1500 rpm with either pure produced biofuels or their blends with Diesel fuel for several ratios (50, 30 and 5 v%) and engine load conditions. The combustion parameters, their blends are compared with those of Diesel fuel.

Combustion-engine control is one of the most important parts of engine application and has a direct impact on its characteristics. Diploma thesis shows the preparation of a test engine and its installation to test cell. It describes measurement and data post processing necessary for common-rail diesel engine control and their application in the creation of a mathematic model in GT-SUITE.

Plenty of designing works focused on railway technology were made through the time. But the majority of them are concerned with high-speed trains or at least express train locomotives, but works devoted to design freight or shunting locomotives can be barely found. This diploma thesis is looking into nearly unexplored territory and finding out, which possibilities in the design of shunting locomotives of independent traction do exist, and find better solutions then those currently used, where possible and appropriate. The result of this master thesis work is design of shunting locomotive, which respects the requirements of railway standards, ergonomics and safety, and still brings in modern design solutions.

Thermal oil oxidation is an important reason for the engine oil degradation in trucks. Having a comprehensive model that includes all the influential factors while it is feasible for being implemented in the ECUs, was aimed for this work. Therefore, the chemical investigating of the problem leaded to propose a first kinetic model and its thermal analysis caused modelling the oil thermal behaviour. The latter was developed for four compartments: Bearings, turbocharger, piston cooling and oil sump in the oil path through the lubrication system, because the highest oil temperature happens due to friction, combustion of fuels and exhaust gas transportation. Independency from the design parameters of the compartments and simplicity of models for the ECU implementation caused to investigate two various modelling hybrid approach: physical modelling and control theory approach. The first one was done for the bearings and piston cooling, and showed a high level of complexity leading to switch to the second approach. The latter was applied for all compartments while it satisfied requested requirements. To adjust and evaluate the models, an experimental campaign was devoted to acquiring the needed parameters with consideration of the project budget. Also using the previous simulation and experimental efforts at the company provided a possibility to develop flow rate sub-models used in the thermal modelling. The proposed model for all compartments, well predicted the oil thermal behaviour for both stationary and dynamic operating conditions. A comparison between the experimental data for the oil in the oil sump and turbo charger was done to show the reliability of the related models in both stationary and transient statuses. For the bearings, the simulation data for stationary condition were applied as a reference. The modelled oil temperature after piston cooling was compared to a set of experimental data that presented the probable temperature in some conditions close to stationary operating points.

In recent decades much effort has gone into reducing particle emissions in the exhaust gases of heavy-duty diesel engines. Engine development has now reached the stage where it is worth to put heavy focus on the contribution of lubricating oil to particulate emissions in order to further reduce these emissions. A literature study demonstrates that the cylinder system is usually the largest source of oil-related particles. Oil consumption in the cylinder can be divided into throw-off effects when inertia forces act on the piston, piston rings and oil; evaporation from hot surfaces; reverse blow-by when gas pressure drives the oil consumption; and top land scraping when oil is scraped off the cylinder liner. The pressure between the compression rings strongly affects the stability and position of the upper compression ring as well as the oil consumption caused by the reverse blow-by. A method to measure the inter-ring pressure was developed and evaluated. The measurements showed that cycle-to-cycle variations were small, but that the inter-ring pressure varied over time. Calculations with AVL Excite Piston and Rings confirmed that ring gap positions can have a major influence on the inter-ring pressure. The measured particle size and number distributions at motoring conditions show interesting and unexpected results. The high number of particles with a diameter of around 100 nm was greatly reduced when the temperature in the diluter was increased. The mean number particle diameter decreased until 10 nm and then became stable independent of further temperature increase. Other authors have found that the small particles (nucleation mode) are reduced and the larger particles (accumulation mode) are more or less unaffected when exhaust gases are heated up and diluted. / QC 20101112