Made available in DSpace on 2017-07-10T19:24:38Z (GMT). No. of bitstreams: 1 Ana Marta Soranso.pdf: 1651613 bytes, checksum: caeedf53d6994dc87ab196226a803114 (MD5) Previous issue date: 2006-07-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to evaluate the dynamic performance of an agricultural tractor utilizing distilled biodiesel (50% ethylic + 50% methylic) in proportion function of biodiesel and diesel of petroleum (0 and 100%, 5 and 95%, 15 and 85%, 25 and 75%, 50 and 50%, 75 and 25% and 100 and 0%) respectively. This research was done in the area of the department of Rural Engineering of the State University Paulista -UNESP, campus of Jaboticabal - SP, located in the latitude 21º 14 28 S e longitude 48º 17 12 W, and a tractor 4x2 FWA was used, with power of 73,6 kW (100 cv) in the motor and a ballast tractor. The used biodiesel was produced the base of residual oil of fried foods. The experimental design was entirely casualized, with 7 treatments and 5 repetitions, totaling 35 observations. The results evidenced that the mixture, biodiesel and diesel, influenced the variables significantly, hourly volumetric consumption, hourly mass consumption, fuel consumption for worked area and specific fuel consumption. When the tractor operated with 100% of biodiesel (B100) the specific consumption increased 18% on average in relation to the diesel (B0). / O objetivo deste trabalho foi avaliar o desempenho dinâmico de um trator agrícola, funcionando com biodiesel destilado (50% etílico + 50% metílico), em função das seguintes proporções de biodiesel e diesel de petróleo: 0 e 100%, 5 e 95%, 15 e 85%, 25 e 75%, 50 e 50%, 75 e 25% e 100 e 0%, respectivamente. O experimento foi realizado em área do departamento de Engenharia Rural da Universidade Estadual Paulista - UNESP, campus de Jaboticabal - SP, localizado na latitude 21º 14 28 S e longitude 48º 17 12 W. Foi utilizado um trator 4x2 TDA, com potência de 73,6 kW (100 cv) no motor e um trator de lastro. O biodiesel utilizado foi produzido à base de óleo residual de fritura de alimentos. O delineamento experimental foi inteiramente casualizado (DIC), com 7 tratamentos e 5 repetições, totalizando 35 observações. Os resultados evidenciaram que a mistura, biodiesel e diesel de petróleo, influenciou significativamente as variáveis: consumo horário volumétrico, consumo horário ponderal, consumo de combustível por área trabalhada e consumo especifico. Quando o trator operou com 100% de biodiesel (B100) o consumo específico aumentou, em média, 18%, em relação ao diesel (B0).

Made available in DSpace on 2017-05-12T14:48:01Z (GMT). No. of bitstreams: 1 Ana Marta Soranso.pdf: 1651613 bytes, checksum: caeedf53d6994dc87ab196226a803114 (MD5) Previous issue date: 2006-07-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The objective of this work was to evaluate the dynamic performance of an agricultural tractor utilizing distilled biodiesel (50% ethylic + 50% methylic) in proportion function of biodiesel and diesel of petroleum (0 and 100%, 5 and 95%, 15 and 85%, 25 and 75%, 50 and 50%, 75 and 25% and 100 and 0%) respectively. This research was done in the area of the department of Rural Engineering of the State University Paulista -UNESP, campus of Jaboticabal - SP, located in the latitude 21º 14 28 S e longitude 48º 17 12 W, and a tractor 4x2 FWA was used, with power of 73,6 kW (100 cv) in the motor and a ballast tractor. The used biodiesel was produced the base of residual oil of fried foods. The experimental design was entirely casualized, with 7 treatments and 5 repetitions, totaling 35 observations. The results evidenced that the mixture, biodiesel and diesel, influenced the variables significantly, hourly volumetric consumption, hourly mass consumption, fuel consumption for worked area and specific fuel consumption. When the tractor operated with 100% of biodiesel (B100) the specific consumption increased 18% on average in relation to the diesel (B0). / O objetivo deste trabalho foi avaliar o desempenho dinâmico de um trator agrícola, funcionando com biodiesel destilado (50% etílico + 50% metílico), em função das seguintes proporções de biodiesel e diesel de petróleo: 0 e 100%, 5 e 95%, 15 e 85%, 25 e 75%, 50 e 50%, 75 e 25% e 100 e 0%, respectivamente. O experimento foi realizado em área do departamento de Engenharia Rural da Universidade Estadual Paulista - UNESP, campus de Jaboticabal - SP, localizado na latitude 21º 14 28 S e longitude 48º 17 12 W. Foi utilizado um trator 4x2 TDA, com potência de 73,6 kW (100 cv) no motor e um trator de lastro. O biodiesel utilizado foi produzido à base de óleo residual de fritura de alimentos. O delineamento experimental foi inteiramente casualizado (DIC), com 7 tratamentos e 5 repetições, totalizando 35 observações. Os resultados evidenciaram que a mistura, biodiesel e diesel de petróleo, influenciou significativamente as variáveis: consumo horário volumétrico, consumo horário ponderal, consumo de combustível por área trabalhada e consumo especifico. Quando o trator operou com 100% de biodiesel (B100) o consumo específico aumentou, em média, 18%, em relação ao diesel (B0).

The greening of air transport is the driver for developing technologies to reduce the environmental impact of aviation with the aim of halving the amount of carbon dioxide (COଶ) emitted by air transport, cutting specific emissions of nitrogen oxides (NO୶) by 80% and halving perceived noise by the year 2020. Fuel Cells (FC) play an important role in the new power generation field as inherently clean, efficient and reliable source of power especially when comparing with the traditional fossil-fuel based technologies. The project investigates the feasibility of using an electric hybrid system consisting of a fuel cell and battery to power a small model aircraft (PiperCub J3). In order to meet the desired power requirements at different phases of flight efficiently, a simulation model of the complete system was first developed, consisting of a Proton Exchange Membrane hybrid fuel cell system, 6DoF aircraft model and neural network based controller. The system was then integrated in one simulation environment to run in real-time and finally was also tested in hardware-in-the-loop with real-time control. The control strategy developed is based on a neural network model identification technique; specifically Model Reference Control (MRC), since neural network is well suited to nonlinear systems. To meet the power demands at different phases of flight, the controller controls the battery current and rate of charging/discharging. Three case studies were used to validate and assess the performance of the hybrid system: battery fully charged (high SOC), worst case scenario and taking into account the external factors such as wind speeds and wind direction. In addition, the performance of the Artificial Neural Network Controller was compared to that of a Fuzzy Logic controller. In all cases the fuel cell act as the main power source for the PiperCub J3 aircraft. The tests were carried-out in both simulation and hardware-in-the-loop.

The greening of air transport is the driver for developing technologies to reduce the environmental impact of aviation with the aim of halving the amount of carbon dioxide (COଶ) emitted by air transport, cutting specific emissions of nitrogen oxides (NO୶) by 80% and halving perceived noise by the year 2020. Fuel Cells (FC) play an important role in the new power generation field as inherently clean, efficient and reliable source of power especially when comparing with the traditional fossil-fuel based technologies. The project investigates the feasibility of using an electric hybrid system consisting of a fuel cell and battery to power a small model aircraft (PiperCub J3). In order to meet the desired power requirements at different phases of flight efficiently, a simulation model of the complete system was first developed, consisting of a Proton Exchange Membrane hybrid fuel cell system, 6DoF aircraft model and neural network based controller. The system was then integrated in one simulation environment to run in real-time and finally was also tested in hardware-in-the-loop with real-time control. The control strategy developed is based on a neural network model identification technique; specifically Model Reference Control (MRC), since neural network is well suited to nonlinear systems. To meet the power demands at different phases of flight, the controller controls the battery current and rate of charging/discharging. Three case studies were used to validate and assess the performance of the hybrid system: battery fully charged (high SOC), worst case scenario and taking into account the external factors such as wind speeds and wind direction. In addition, the performance of the Artificial Neural Network Controller was compared to that of a Fuzzy Logic controller. In all cases the fuel cell act as the main power source for the PiperCub J3 aircraft. The tests were carried-out in both simulation and hardware-in-the-loop.

In this thesis, the dynamic performances of kinematically and dynamically adjustable planar mechanisms have been investigated. An adjustable mechanism is here defined to be a mechanism where some of the kinematic and/or dynamic parameters are changed in a controlled manner in order to optimize the dynamic behaviour of the mechanism in spite of variable operating conditions. Here, variable operating conditions refer to variable load(s) on the mechanism and/or variable desired input motion. The dynamic behaviour of the mechanism may be optimized via minimization of the actuator torque/force fluctuations, minimization of energy consumed by the actuators etc. According to the type of the adjustable parameter, the adjustable mechanisms are classified into two groups namely, dynamically adjustable mechanisms and kinematically adjustable mechanisms. Mechanisms, where the main concern is to change a dynamic parameter(s) are called dynamically adjustable mechanisms. In the kinematically adjustable mechanisms, on the other hand , the main concern is to change a kinematic parameter(s). The main objective of this study is to investigate the benefits of adjustable planar mechanisms, regarding different dynamic behaviours under variable operating conditions. To achieve this objective , various simulations have been performed on the computer. In these simulations, practical constraints that will exist in a real application have been taken into account as much as possible. The results reveal that, in many cases, the dynamic behaviour of a planar mechanism may be improved quite extensively via adjustable mechanisms which are obtained from the original mechanisms with slight modifications.

Over the last decades, the frequency on the Nordic electrical power grid has deteriorated. Therefore, new stricter requirements are developed for the hydropower delivering regulating active power on the Frequency Containment Reserve market (FCR). This thesis aims to investigate the possibility of modeling two double-regulated hydropower plants, referred to as Unit 1 and 2, to evaluate their compliance with the new FCR-requirements.  By modeling the hydropower plants, the first goal was to find a model structure that captures the essential dynamics of the systems. A second goal was to evaluate whether the two units currently fulfill the new FCR-requirements, and investigate how the turbine governors’ settings could be optimized to fulfill the new requirements. Data obtained from FCR-tests was used in MATLAB to evaluate the two stations’ dynamic stability and performance requirements. Through system identification in MATLAB, grey-box modeling was used to create linear and non-linear turbine and waterways models for Unit 1 and Unit 2. The non-linear turbine and waterways models were implemented in Simulink, together with corresponding turbine governors, to find optimal parameter settings to fulfill the FCR-requirements.  The evaluation of the new FCR-requirements shows that none of the two units fulfills the dynamic stability requirement. However, Unit 1 fulfills the performance requirement. The results imply that double-regulated turbines will most likely have difficulties fulfilling the new requirements, which will cause major consequences in improving the frequency regulation quality. The results from the grey-box modeling present that the linear models are not validated with the step response data, due to not capturing the system dynamics when compared with provided data from the units. On the other hand, the non-linear models are validated with step response data as the model captures the system dynamics more accurately. However, the non- linear Simulink models cannot capture the dynamics of the hydropower systems for sinusoidal signals with varying frequencies which are used in the new FCR-requirement test. Consequently, the thesis has no result of the optimal parameter setting of the turbine governors to fulfill the new FCR-requirements. In conclusion, the grey-box models, with the level of detail presented in this thesis, are inadequate in capturing the system’s dynamics to evaluate the new FCR-requirements. Thus, the thesis contributes to filling a knowledge gap within the area of modeling for frequency regulation.

Advanced digital signal processing systems require specialized high-performance embedded computer architectures. The term high-performance translates to large amounts of data and computations per time unit. The term embedded further implies requirements on physical size and power efficiency. Thus the requirements are of both functional and non-functional nature. This thesis addresses the development of high-performance digital signal processing systems relying on manycore technology. We propose building two-level hierarchical computer architectures for this domain of applications. Further, we outline a tool flow based on methods and analysis techniques for automated, multi-objective mapping of such applications on distributed memory manycore processors. In particular, the focus is put on how to provide a means for tunable strategies for mapping of task graphs on array structured distributed memory manycores, with respect to given application constraints. We argue for code mapping strategies based on predicted execution performance, which can be used in an auto-tuning feedback loop or to guide manual tuning directed by the programmer. Automated parallelization, optimisation and mapping to a manycore processor benefits from the use of a concurrent programming model as the starting point. Such a model allows the programmer to express different types and granularities of parallelism as well as computation characteristics of importance in the addressed class of applications. The programming model should also abstract away machine dependent hardware details. The analytical study of WCDMA baseband processing in radio base stations, presented in this thesis, suggests dataflow models as a good match to the characteristics of the application and as execution model abstracting computations on a manycore. Construction of portable tools further requires a manycore machine model and an intermediate representation. The models are needed in order to decouple algorithms, used to transform and map application software, from hardware. We propose a manycore machine model that captures common hardware resources, as well as resource dependent performance metrics for parallel computation and communication. Further, we have developed a multifunctional intermediate representation, which can be used as source for code generation and for dynamic execution analysis. Finally, we demonstrate how we can dynamically analyse execution using abstract interpretation on the intermediate representation. It is shown that the performance predictions can be used to accurately rank different mappings by best throughput or shortest end-to-end computation latency.

Le besoin en isolation vibratoire des voies ferrées conduit de plus en plus souvent au recours à des systèmes d'attache de rail souples avec des designs sophistiqués. Par contre, les produits deviennent diversifiés mais leur conception se fait de manière empirique dans la pratique. Dans ce travail de thèse, deux systèmes d'attache de rail sont étudiés expérimentalement et numériquement: un système qui travaille principalement en cisaillement et l'autre en compression. Des essais quasi-statiques et dynamiques sont menés puis les résultats sont analysés à l'aide de différents modèles mécaniques. En plus, une série de tests sur les élastomères utilisés dans les deux systèmes sont réalisés. Ces tests permettent de choisir des modèles hyperélastiques et viscoélastique appropriés, et de déterminer les paramètres de propriétés mécaniques des élastomères dans ces modèles par des simulations Abaqus. En utilisant également Abaqus, des analyses par élément fini des deux systèmes d'attache sont effectués et les résultats sont comparés aux ceux des essais. Des non-linéarités d'origine matérielle et géométrique sont ainsi analysées et expliquées. Enfin, des études de sensibilité des paramètres sont effectuées, suivies d'études d'optimisation structurale. Cet étude devrait être utile pour une meilleure compréhension du comportement mécanique des systèmes d'attache de rail sous chargement statique et dynamique, et au final pour une meilleure pratique dans la conception et l'optimisation des produits / Higher demand on vibration isolation of track structure in modern railway track leads to a trend of lower stiffness of rail fastening systems, places an increasing need for better design approach as well. However the current development status of rail fastening industry is dramatically diversified but mainly empirical. In this work, a shear type and a bonded compressed type of rail fastening systems are investigated experimentally and numerically. Quasi-static and dynamic experiments are carried out and the results are analysed with different mechanical models. Besides, a series of fundamental rubber material tests is performed to accurately describe the rubber material used in the two fastening systems. The most appropriate hyperelastic and hysteresis models are chosen with the help of simulations by Abaqus. Also by using Abaqus, finite element analyses are conducted for the two fastening systems and the numerical results are compared with those of experiments. Material and geometrical nonlinear features observed in the measured displacement-force curves are analysed and explained. Finally, parameter sensitivity of the two fastening specimens are studied, followed by an optimization process to meet practical optimization objectives. The present work is believed to be helpful for understanding the mechanical behavior of rail fastening systems, while enlightening the engineering practice, and eventually improving product designing and optimizing measures

Le besoin en isolation vibratoire des voies ferrées conduit de plus en plus souvent au recours à des systèmes d'attache de rail souples avec des designs sophistiqués. Par contre, les produits deviennent diversifiés mais leur conception se fait de manière empirique dans la pratique. Dans ce travail de thèse, deux systèmes d'attache de rail sont étudiés expérimentalement et numériquement: un système qui travaille principalement en cisaillement et l'autre en compression. Des essais quasi-statiques et dynamiques sont menés puis les résultats sont analysés à l'aide de différents modèles mécaniques. En plus, une série de tests sur les élastomères utilisés dans les deux systèmes sont réalisés. Ces tests permettent de choisir des modèles hyperélastiques et viscoélastique appropriés, et de déterminer les paramètres de propriétés mécaniques des élastomères dans ces modèles par des simulations Abaqus. En utilisant également Abaqus, des analyses par élément fini des deux systèmes d'attache sont effectués et les résultats sont comparés aux ceux des essais. Des non-linéarités d'origine matérielle et géométrique sont ainsi analysées et expliquées. Enfin, des études de sensibilité des paramètres sont effectuées, suivies d'études d'optimisation structurale. Cet étude devrait être utile pour une meilleure compréhension du comportement mécanique des systèmes d'attache de rail sous chargement statique et dynamique, et au final pour une meilleure pratique dans la conception et l'optimisation des produits / Higher demand on vibration isolation of track structure in modern railway track leads to a trend of lower stiffness of rail fastening systems, places an increasing need for better design approach as well. However the current development status of rail fastening industry is dramatically diversified but mainly empirical. In this work, a shear type and a bonded compressed type of rail fastening systems are investigated experimentally and numerically. Quasi-static and dynamic experiments are carried out and the results are analysed with different mechanical models. Besides, a series of fundamental rubber material tests is performed to accurately describe the rubber material used in the two fastening systems. The most appropriate hyperelastic and hysteresis models are chosen with the help of simulations by Abaqus. Also by using Abaqus, finite element analyses are conducted for the two fastening systems and the numerical results are compared with those of experiments. Material and geometrical nonlinear features observed in the measured displacement-force curves are analysed and explained. Finally, parameter sensitivity of the two fastening specimens are studied, followed by an optimization process to meet practical optimization objectives. The present work is believed to be helpful for understanding the mechanical behavior of rail fastening systems, while enlightening the engineering practice, and eventually improving product designing and optimizing measures

This work presents the result achieved through investigation of RH-2 gas-lift valve dynamic performance. It is an unbalanced gas-lift valve injection pressure operated, for high injection pressure applications. First, a CFD model was developed in order to obtain the valve orifice flow pattern performance curve. The CFD curve was compared with the curve experimentally obtained, conceiving very promising results. A test bench, and the necessary test devices, have been projected and built looking forward to determine the bellows load rate. Second, a CFD mesh deformation model was developed, which allowed the determination of dynamic performance curves on orifice, transition and throttling flow patterns for a given bellows pressure. The accuracy of the mesh deformation model was verified comparing the obtained curve with experimental results. The results of numerous CFD model simulations allowed to correlate data and to find a transition pressure, the production pressure for the maximum gas throughput and the product of the discharge coefficient by the expansion factor. The mathematical model developed allows predicting the gas throughput capacity of the gas-lift valve using injection pressure, production pressure and bellows pressure, for a defined load rate and a defined port diameter. / Nos primeiros estágios de produção, um poço de petróleo apresenta um fluxo natural, sendo a energia necessária para elevação dos fluidos até a superfície fornecida pelo próprio reservatório. Neste caso, diz-se que o poço é surgente. Entretanto, na medida em que as reservas são produzidas, a pressão do reservatório diminui e surge a necessidade de complementar artificialmente a energia requerida para a elevação. Diz-se, então, que o poço produz por elevação artificial. De todos os métodos de elevação artificial, o gas lift é o mais amplamente utilizado, e para a sua implementação são requeridas as chamadas válvulas de gas lift. O conhecimento do comportamento dinâmico da válvula de gas lift é fundamental na etapa de projeto e no estabelecimento de estratégias operacionais eficientes. Este trabalho apresenta os resultados obtidos no estudo do desempenho dinâmico da válvula de gas-lift RH-2, a qual consiste em uma válvula de gas lift não balanceada operada por pressão e de alta pressão de carregamento no fole, fabricada pela Weatherford, e que não dispõe de um modelo para o levantamento de suas curvas de desempenho dinâmico. Inicialmente, foi desenvolvido um modelo fluidodinâmico utilizando-se Dinâmica de Fluidos Computacional (CFD) para a obtenção da curva de desempenho no regime de orifício e este foi comparado com dados obtidos experimentalmente, produzindo resultados muito promissores. Uma bancada de testes com os dispositivos necessários foi projetada e construída para o levantamento da taxa de carga do fole. A seguir, foi desenvolvido um modelo fluidodinâmico da válvula no aplicativo CFX, utilizando uma malha deformável, que permitiu a geração das curvas de desempenho nos regimes de orifício, transição e estrangulamento para uma dada pressão de carregamento do fole. A precisão da malha deformável foi verificada comparando a curva obtida para diversas posições da haste com resultados experimentais. Os resultados das várias simulações do modelo fluidodinâmico permitiram correlacionar dados e calcular a pressão de transição, a pressão de produção onde ocorre a vazão máxima e o produto do coeficiente de descarga pelo fator de expansão. O modelo matemático desenvolvido permite predizer a vazão de gás que escoa pela válvula de gas lift a partir da pressão de injeção, da pressão de produção e da pressão de carregamento no fole, para uma taxa de carga do fole e um diâmetro de porta definidos.