O projeto do coletor de admissão é essencial para alcançar o melhor desempenho de um motor de combustão interna, e, portanto diversos parâmetros devem ser considerados durante o desenvolvimento do mesmo. Por exemplo, uma distribuição de ar não uniforme conduz a uma eficiência volumétrica não uniforme no cilindro, perda de potência e aumento do consumo de combustível. Por outro lado, as variações de pressão no coletor de admissão, devido aos efeitos pulsantes no escoamento do ar podem substancialmente aumentar ou reduzir o desempenho do motor. Atualmente, no Brasil, a maior parte dos coletores de admissão é fabricada a partir do nylon com fibra de vidro, pois proporciona redução de peso, redução de atrito nos dutos e geometrias internas complexas. Porém, novos fatores se tornam importante como redução de integridade estrutural e atender a requisitos de pressão de estouro. Este trabalho apresenta as principais etapas de desenvolvimento de um coletor de admissão plástico soldado por vibração. Primeiramente as principais dimensões do coletor são definidas a partir da simulação unidimensional. A partir disso, o modelo tridimensional é construído levando em consideração o espaço disponível no compartimento do motor e aspectos que permitam a injeção e solda das partes. Em seguida, a geometria interna do coletor é otimizada visando diminuir as perdas de carga aumentando a eficiência volumétrica. A integridade estrutural do coletor e solda deve ser analisada a fim de atender os requisitos do cliente. Ao confirmar o desenho do coletor de admissão através de testes com peças protótipos, se inicia a fabricação dos ferramentais de produção. / Intake manifold project is essential to achieve the best internal combustion engine performance, and, therefore, several parameters should be considered during it development. For instance, an uneven air distribution lead to uneven cylinder volumetric efficiency, power loss and increased fuel consumption. On the other hand, pressures variations within intake manifold due to air flow transient effects could substantially increase or decrease the engine performance. Nowadays, in Brazil, the majority of the intake manifolds are fabricated from nylon with glass fiber which provides weight reduction, wall friction reduction and complex internal geometries. However, new factors become important like structural integrity reduction and withstand to burst pressure. This work presents the mainly development stages of a plastic intake manifold vibration welded. First, the basic intake manifold dimensions are defined through one-dimensional simulation. From this, three-dimensional model is built considering the engine compartment space available and aspects which allows injection and welding process of manifold shells. Then, intake manifold internal geometry is optimized to minimize air flow losses, increasing the volumetric efficiency. Intake manifold structural integrity and welding quality should de evaluated to withstand customer requirements. Confirming the intake manifold drawing through tests with prototype parts, production tooling is started.

O projeto do coletor de admissão é essencial para alcançar o melhor desempenho de um motor de combustão interna, e, portanto diversos parâmetros devem ser considerados durante o desenvolvimento do mesmo. Por exemplo, uma distribuição de ar não uniforme conduz a uma eficiência volumétrica não uniforme no cilindro, perda de potência e aumento do consumo de combustível. Por outro lado, as variações de pressão no coletor de admissão, devido aos efeitos pulsantes no escoamento do ar podem substancialmente aumentar ou reduzir o desempenho do motor. Atualmente, no Brasil, a maior parte dos coletores de admissão é fabricada a partir do nylon com fibra de vidro, pois proporciona redução de peso, redução de atrito nos dutos e geometrias internas complexas. Porém, novos fatores se tornam importante como redução de integridade estrutural e atender a requisitos de pressão de estouro. Este trabalho apresenta as principais etapas de desenvolvimento de um coletor de admissão plástico soldado por vibração. Primeiramente as principais dimensões do coletor são definidas a partir da simulação unidimensional. A partir disso, o modelo tridimensional é construído levando em consideração o espaço disponível no compartimento do motor e aspectos que permitam a injeção e solda das partes. Em seguida, a geometria interna do coletor é otimizada visando diminuir as perdas de carga aumentando a eficiência volumétrica. A integridade estrutural do coletor e solda deve ser analisada a fim de atender os requisitos do cliente. Ao confirmar o desenho do coletor de admissão através de testes com peças protótipos, se inicia a fabricação dos ferramentais de produção. / Intake manifold project is essential to achieve the best internal combustion engine performance, and, therefore, several parameters should be considered during it development. For instance, an uneven air distribution lead to uneven cylinder volumetric efficiency, power loss and increased fuel consumption. On the other hand, pressures variations within intake manifold due to air flow transient effects could substantially increase or decrease the engine performance. Nowadays, in Brazil, the majority of the intake manifolds are fabricated from nylon with glass fiber which provides weight reduction, wall friction reduction and complex internal geometries. However, new factors become important like structural integrity reduction and withstand to burst pressure. This work presents the mainly development stages of a plastic intake manifold vibration welded. First, the basic intake manifold dimensions are defined through one-dimensional simulation. From this, three-dimensional model is built considering the engine compartment space available and aspects which allows injection and welding process of manifold shells. Then, intake manifold internal geometry is optimized to minimize air flow losses, increasing the volumetric efficiency. Intake manifold structural integrity and welding quality should de evaluated to withstand customer requirements. Confirming the intake manifold drawing through tests with prototype parts, production tooling is started.

The aim of this diploma thesis is to analyse flight performance of airplane VUT-081 Kondor. The first part focuses on determination and estimation of aerodynamic characteristics of the airplane. Based on this data flight performance was calculated and evaluated according to CS-ELSA. The last part is dedicated to comparison of flight performance of VUT-081 Kondor with other similar airplanes.

No description available.

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / During engine and airfield performance testing it is often necessary to acquire weather data at the airfield where the test is being conducted. The airborne data acquisition system (DAS) acquires data associated with flight parameters. A separate system records airport weather conditions. Many times the separate system is an Automated Terminal Information Service (ATIS) or the ground crew relaying wind speed, wind direction and temperature from a weather station. To improve this system, the weather station is designed to acquire and store the data in memory. Utilizing a second DAS that is remote to the airborne DAS poses several problems. First, it is undesirable to have many different data acquisition systems from which to process data. The problem then develops into one of integrating the ground weather DAS with the existing airborne DAS. Other problems of system integrity, compatibility and FCC licensing exist. Complete system integration while maintaining integrity and compatibility is overcome by controlling signal format, flow and timing and is discussed in detail. Further discussion of the issue of transmission is overcome by a technique called spread-spectrum and is used in accordance with FCC rules and regulations.

No description available.

The thesis presents an experimental investigation of combustion performance and emissions of waste cooking oil (WCO) based biodiesel. To evaluate the comparative performance of biodiesel and diesel, combustions tests were conducted using Continuous Combustion rig (CCR) and Land Rover VM diesel engine. Firstly, physical properties of WCO biodiesel and diesel samples were measured in the laboratory. Elemental analysis of WCO biodiesel showed that there are differences between the functional groups in diesel and biodiesel which lead to major differences in the combustion characteristics of the two fuel types. It was found that biodiesel had 10% lower carbon content, almost no sulphur content for biodiesel and up to 12% more oxygen content compared with diesel. This explains the lower caloric value for WCO biodiesel (up to l8 %) compared with diesel. However, higher oxygen content and double bounds in WCO biodiesel increase its susceptibility to oxidation. The CCR test results showed an increase in combustion gas temperature with the increases in biodiesel blend ratio in diesel. This was due to a faster reaction rate for biodiesel than that of diesel leading to a faster brakeage of the hydrocarbon chain to release more heat. The engine tests were performed to measure the torque and emissions for different engine speeds and loads. In general a decrease in engine torque with up to 9% for biodiesel was observed, which was due to the lower calorific value of biodiesel compared with that of diesel. The brake specific fuel consumption (BSFC) increased as the biodiesel blend ratio in diesel increases due a greater mass of fuel being injected at a given injection pressure, compared with diesel. Using WCO blends ratio up to 75% in diesel showed a reduction in exhaust emission compared with diesel, however, at the cost of increased fuel consumption. A common conclusion can be drawn in favour of the WCO biodiesel as being a greener alternative to petro-diesel when used in blend with diesel. However, due to large variations in the biomass used for biodiesel production could lead to variations in physical and chemical properties between biodiesel produced from different biomass. Therefore more stringent standards need to be imposed for biodiesel quality in order to diminish the effect of variation in physicochemical properties on engine performance and emissions. The future work in developing standard test procedures for establishing fuel properties and limits/targets would be beneficial in using a large amount of waste cooking oil in the production of biodiesel, thus contributing to reduction in CO2 and waste minimisation.

In this thesis, exergy based SI engine model optimisation (EBSIEMO) is studied and evaluated. A four-stroke bi-fuel spark ignition (SI) engine is modelled for optimisation of engine performance based upon exergy analysis. An artificial neural network (ANN) is used as an emulator to speed up the optimisation processes. Constrained particle swarm optimisation (CPSO) is employed to identify parameters such as equivalence ratio and ignition time for optimising of the engine performance, based upon maximising 'total availability'. In the optimisation process, the engine exhaust gases standard emission were applied including brake specific CO (BSCO) and brake specific NOx (BSNOx) as the constraints. The engine model is developed in a two-zone model, while considering the chemical synthesis of fuel, including 10 chemical species. A computer code is developed in MATLAB software to solve the equations for the prediction of temperature and pressure of the mixture in each stage (compression stroke, combustion process and expansion stroke). In addition, Intake and exhaust processes are calculated using an approximation method. This model has the ability to simulate turbulent combustion and compared to computational fluid dynamic (CFD) models it is computationally faster and efficient. The selective outputs are cylinder temperature and pressure, heat transfer, brake work, brake thermal and volumetric efficiency, brake torque, brake power (BP), brake specific fuel consumption (BSFC), brake mean effective pressure (BMEP), concentration of CO2, brake specific CO (BSCO) and brake specific NOx (BSNOx). In this model, the effect of engine speed, equivalence ratio and ignition time on performance parameters using gasoline and CNG fuels are analysed. In addition, the model is validated by experimental data using the results obtained from bi-fuel engine tests. Therefore, this engine model was capable to predict, analyse and useful for optimisation of the engine performance parameters. The exergy based four-stroke bi-fuel (CNG and gasoline) spark ignition (SI) engine model (EBSIEM) here is used for analysis of bi-fuel SI engines. Since, the first law of thermodynamic (the FLT), alone is not able to afford an appropriate comprehension into engine operations. Therefore, this thesis concentrates on the SI engine operation investigation using the developed engine model by the second law of thermodynamic (the SLT) or exergy analysis outlook (exergy based SI engine model (EBSIEM)) In this thesis, an efficient approach is presented for the prediction of total availability, brake specific CO (BSCO), brake specific NOx (BSNOx) and brake torque for bi-fuel engine (CNG and gasoline) using an artificial neural network (ANN) model based on exergy based SI engine (EBSIEM) (ANN-EBSIEM) as an emulator to speed up the optimisation processes. In the other words, the use of a well trained an ANN is ordinarily much faster than mathematical models or conventional simulation programs for prediction. The constrained particle swarm optimisation (CPSO)-EBSIEM (EBSIEMO) was capable of optimising the model parameters for the engine performance. The optimisation results based upon availability analysis (the SLT) due to analysing availability terms, specifically availability destruction (that measured engine irreversibilties) are more regarded with higher priority compared to the FLT analysis. In this thesis, exergy based SI engine model optimisation (EBSIEMO) is studied and evaluated. A four-stroke bi-fuel spark ignition (SI) engine is modelled for optimisation of engine performance based upon exergy analysis. An artificial neural network (ANN) is used as an emulator to speed up the optimisation processes. Constrained particle swarm optimisation (CPSO) is employed to identify parameters such as equivalence ratio and ignition time for optimising of the engine performance, based upon maximising 'total availability'. In the optimisation process, the engine exhaust gases standard emission were applied including brake specific CO (BSCO) and brake specific NOx (BSNOx) as the constraints. The engine model is developed in a two-zone model, while considering the chemical synthesis of fuel, including 10 chemical species. A computer code is developed in MATLAB software to solve the equations for the prediction of temperature and pressure of the mixture in each stage (compression stroke, combustion process and expansion stroke). In addition, Intake and exhaust processes are calculated using an approximation method. This model has the ability to simulate turbulent combustion and compared to computational fluid dynamic (CFD) models it is computationally faster and efficient. The selective outputs are cylinder temperature and pressure, heat transfer, brake work, brake thermal and volumetric efficiency, brake torque, brake power (BP), brake specific fuel consumption (BSFC), brake mean effective pressure (BMEP), concentration of CO2, brake specific CO (BSCO) and brake specific NOx (BSNOx). In this model, the effect of engine speed, equivalence ratio and ignition time on performance parameters using gasoline and CNG fuels are analysed. In addition, the model is validated by experimental data using the results obtained from bi-fuel engine tests. Therefore, this engine model was capable to predict, analyse and useful for optimisation of the engine performance parameters. The exergy based four-stroke bi-fuel (CNG and gasoline) spark ignition (SI) engine model (EBSIEM) here is used for analysis of bi-fuel SI engines. Since, the first law of thermodynamic (the FLT), alone is not able to afford an appropriate comprehension into engine operations. Therefore, this thesis concentrates on the SI engine operation investigation using the developed engine model by the second law of thermodynamic (the SLT) or exergy analysis outlook (exergy based SI engine model (EBSIEM)) In this thesis, an efficient approach is presented for the prediction of total availability, brake specific CO (BSCO), brake specific NOx (BSNOx) and brake torque for bi-fuel engine (CNG and gasoline) using an artificial neural network (ANN) model based on exergy based SI engine (EBSIEM) (ANN-EBSIEM) as an emulator to speed up the optimisation processes. In the other words, the use of a well trained an ANN is ordinarily much faster than mathematical models or conventional simulation programs for prediction. The constrained particle swarm optimisation (CPSO)-EBSIEM (EBSIEMO) was capable of optimising the model parameters for the engine performance. The optimisation results based upon availability analysis (the SLT) due to analysing availability terms, specifically availability destruction (that measured engine irreversibilties) are more regarded with higher priority compared to the FLT analysis.

É apresentada uma metodologia para descrever o mapa de desempenho (ou mapa de consumo de combustível) de um motor de combustão interna como função de suas condições de operação (rotação e torque) baseados em medições embarcadas. É utilizada para este levantamento a combinação de medições via GPS (para a velocidade longitudinal e inclinação de pista) e OBD-II para aquisição de sinais da rede CAN, como rotação do motor e consumo de combustível. É desenvolvida uma metodologia para o cálculo do torque líquido do motor baseado na medição de velocidade e aceleração longitudinal do veículo com uma margem de incerteza de 2% a 5% no cálculo do torque em condições normais de operações. É realizado um detalhamento da origem das incertezas para avaliar a contribuição individual de cada parâmetro. Um modelo de regressão polinomial é utilizado para descrever o mapa de consume de combustível do motor cujos coeficientes característicos são determinados experimentalmente através da metodologia proposta para cinco veículos diferentes a fim de comprovar a eficácia da metodologia. Os coeficientes de correlação variam de 0.797 a 0.997, sendo que em três de cinco veículos o coeficiente de correlação é maior que 0.910, comprovando a robustez da metodologia. / It is presented a methodology to describe the engine performance map (or the engine fuel map) for an internal combustion engine as a function of its operating conditions (engine speed and torque) based on on-board measurements. It is used a combination of GPS measurements for vehicle speed and road grade together with a OBD-II acquisition system in order to acquire information provided by CAN network, such as engine speed and fuel consumption. A methodology to calculate the engine torque based on speed and acceleration measurements is shown with an average uncertainty in the range of 2% to 5% for torque calculation in normal operating conditions. It is presented a detailed breakdown of the contribution of individual parameters in torque calculation uncertainty. A polynomial regression model to describe the engine fuel map is presented and the coefficients for this model is calculated based on on-road measurements for 5 different vehicles to prove the accuracy of the proposed methodology. The correlation coefficients obtained for these measurements are within the range of 0.797 to 0.997 and three out of five vehicles with correlation coefficient higher than 0.910, proving the methodology robust.

Increasing fuel prices, stricter government policies, and technological developments made it possible to seek for renewable alternatives, called biofuels, to petroleum fuel. Biodiesel, a biofuel that is produced from chemically mixing animal fat, vegetable oils, or recycled restaurant grease with alcohol and catalyst, is gaining popularity in recent years as a substitute for petroleum diesel. Ninety percent (90%) of U.S. biodiesel industry makes use of soybean oil as its feedstock. However, soybean oil alone cannot meet such a huge demand on biofuel production. Hence, it is important to identify and get more information about other feedstocks, specifically on its effects on the performance and exhaust emissions of diesel engines. The purpose of this study is to investigate the performance and emissions of two diesel engines operating on different biodiesel fuels (i.e. canola oil, sunflower oil, safflower oil, peanut oil, and chicken fat) and compare them to the performance and emissions when the engine is operated on soybean oil-based biodiesel and petroleum-based diesel. Results indicated that an engine operating on biodiesel generates a little less power and torque at any given speed than one running on diesel. Such power and torque loss were attributed to the biodiesel's lower energy content. The lower heating value (energy content) of biodiesel can be reflected in the specific fuel consumption, i.e., to generate the same power, more biodiesel is needed. The reduction in torque and power of less than 10% indicates that in some cases biodiesel has better combustion than diesel. Unfortunately, the high efficiency of combustion may give rise to increased combustion temperature which may lead to higher exhaust emissions. The gradual decrease in the total hydrocarbon and CO2 emissions, as blends were increased from B20 to B100, was also found to be an indication of better combustion using biodiesel fuels than petroleum diesel. However, NOx emissions were higher, predominantly at low speeds for most biodiesel and blends and therefore may require some additives or engine modifications/or adjustments to equalize the NOx emissions of diesel. Other emissions particularly SO2 were lower than standards require.