During gas turbine development testing, measurements of the gas-path stagnation temperature are used to characterise the engine running condition and establish individual engine component performance. These measurements are typically acquired using passively ventilated thermocouple probes, which are capable of achieving absolute stagnation temperature uncertainties of approximately 0.5 %. Historically, this measurement accuracy has been considered adequate to evaluate gains in turbomachinery efficiency. However, realisable turbomachinery efficiency gains have recently become sufficiently small that an improvement in measurement accuracy is now required. This has resulted in the specification of a target absolute stagnation temperature uncertainty of 0.1 %. The research presented in this thesis focusses on the development of a new stagnation temperature probe that will achieve a measurement uncertainty close to the target value. The new probe has been designed to utilise a thin-film platinum resistance thermometer (PRT) as the temperature sensitive element. For certain aspects of gas turbine engine testing, this type of sensor offers an improvement in measurement accuracy compared to a thermocouple.

<p>The present work relates to a new procedure, to perform temperature measurements with unprecedented accuracy. The new approach relies on a correction based on a two-wire probe thermocouple that enables a precise estimation of the conduction error. The difference between measured temperature by a thermocouple and total gas temperature for steady conditions can be decomposed into three main contributions: velocity error, conduction error and radiation error. Radiation error can be considered negligible for temperatures lower than 800K. The velocity error can be corrected using dedicated experimental calibrations to measure the recovery factor. However, the conduction error, remains an unresolved challenge in the aerospace and power-energy community. The proposed method includes a comprehensive correction with different options for the postprocessing. The method has been demonstrated using high-fidelity aero-structural computational simulations.</p>

For the supersonic flow mode, which occurs in the internal flow behind the aperture separating two spaces with a large pressure drop, the critical flow is a characteristic phenomenon. In the case of critical flow behind the aperture, a supersonic flow area with reduced pressure ending with a shock wave with a step change in state variables is created. When diagnosing velocities, which are obtained from the values of static and total pressure, due to the changes caused by the shock wave passage, correction of the diagnostic quantities obtained by measuring by means of mathematical relations taking into account the physical phenomena is necessary.

This thesis is based on the series of scholarly article dedicated to the issue ofpumping in the differential scanning chamber of an environmental scanning microscope. The thesis is based on Danilatos’s study where the pumping of the differential pumped chamber is solved by means of the Monte Carlo statistical method. The thesis performs analysis of gas flow at low pressures through orifice separating the spaces with a large pressure drop Dr. Danilate. The analyses will be used for the design of the experimental chamber which will serve for the experimental evaluation of the flow results in the chamber using the continuum mechanics.

[pt] A injeção de emulsão é um método comum para melhorar o varrido do reservatório e manter-lo pressurizado. A eficiência de recuperação de óleo no caso de óleos pesados é limitada pela alta razão de mobilidade entre a água injetada e o óleo. Um método de reduzir o problema relativo µa alta razão de viscosidade é por injeção de soluções poliméricas. Porem, a interação líquido- rocha, os grandes volumes e o preço associado dos polímeros podem fazer esta técnica não aplicável em caso de campos gigantes. Diferentes métodos de recuperação avançada de óleo estão sendo desenvolvidos como alternativas µa injeção de polímeros. A injeção de dispersões, em particular a injeção de emulsões, têm sido tratadas com relativo sucesso como um método de recuperação avançada de óleo, mas as técnicas não são totalmente desenvolvidas ou compreendidas. O uso de cada método requer uma completa análise dos diferentes regimes de fluxo de emulsões dentro do espaço poroso de um reservatório. A maioria das análises de fluxo de emulsões em um meio poroso utiliza uma descrição macroscópica. Esta aproximãção é só valida para emulsões com o tamanho da fase dispersa muito menor do que o tamanho do poro. Se o tamanho de gota da fase dispersa é da mesma ordem de magnitude do tamanho de poro, as gotas podem aglomera-se e particularmente podem bloquear o fluxo através dos poros. Este regime de fluxo pode ser utilizado para controlar a mobilidade do líquido injetado, conduzindo a um fator de recuperação maior. Neste trabalho, experimentos de deslocamento de óleo foram executados em um corpo de prova de arenito. Os resultados mostram que a injeção de uma emulsão mudou o fator de recuperação de óleo, elevando este desde 40%, obtido só por injeção de água, ate um valor aproximado de 75%, seja em modo primario ou depois do influxo da água. / [en] Water injection is a common method to improve the reservoir sweep and maintain its pressure. The e±ciency of oil recovery in the case of heavy oils is limited by the high mobility ratio between the injected water and oil. A method of reducing the problem related to the high viscosity ratio is by polymer solution injection. However, the liquid-rock interaction, the large volume and the associated cost of polymer may make this technique not applicable in the case of giant fields. Different enhanced oil recovery methods are being developed and studied as alternatives to polymer injection. Dispersion injection, in particular oil-water emulsion injection, has been tried with relative success as an enhanced oil recovery method, but the techniques are not fully developed or understood. The use of such methods requires a complete analysis of the different flow regimes of emulsions inside the porous space of a reservoir. Most analyses of flow of emulsion in a porous media use a macroscopic description. This approach is only valid for dilute emulsion which the size of the disperse phase is much smaller of the pore throat. If the drop size of the disperse phase is of the same order of magnitude of the pore size, the drops may agglomerate and partially block the flow through pores. This flow regime may be used to control the mobility of the injected liquid, leading to higher recovery factor. In this work, experiments of oil displacement were performed in a sandstone plug. The results show that injection of an emulsion changed the oil recovery factor, raising it from approximately 40%, obtained with water injection alone, to approximately 75%, whether in primary mode or after water flooding.

Made available in DSpace on 2014-12-17T14:08:51Z (GMT). No. of bitstreams: 1 RutinaldoAN_DISSERT.pdf: 3892841 bytes, checksum: c2e0ab636612eb7f303f7c05dcbc863a (MD5) Previous issue date: 2012-08-28 / Como os recursos de hidrocarbonetos convencionais est?o se esgotando, a crescente demanda mundial por energia impulsiona a ind?stria do petr?leo para desenvolver mais reservat?rios n?o convencionais. Os recursos mundiais de betume e ?leo pesado s?o estimados em 5,6 trilh?es de barris, dos quais 80% est?o localizados na Venezuela, Canad? e EUA. Um dos m?todos para explorar estes hidrocarbonetos ? o processo de drenagem gravitacional assistido com inje??o de vapor e solvente (ES-SAGD Expanding Solvent Steam Assisted Gravity Drainage). Neste processo s?o utilizados dois po?os horizontais paralelos e situados verticalmente um acima do outro, um produtor na base do reservat?rio e um injetor de vapor e solvente no topo do reservat?rio. Este processo ? composto por um m?todo t?rmico (inje??o de vapor) e um m?todo misc?vel (inje??o de solvente) com a finalidade de causar a redu??o das tens?es interfaciais e da viscosidade do ?leo ou betume. O objetivo deste estudo ? analisar a sensibilidade de alguns par?metros operacionais, tais como: tipo de solvente injetado, qualidade do vapor, dist?ncia vertical entre os po?os, porcentagem de solvente injetado e vaz?o de inje??o de vapor sobre o fator de recupera??o para 5, 10 e 15 anos. Os estudos foram realizados atrav?s de simula??es concretizadas no m?dulo STARS (Steam Thermal, and Advanced Processes Reservoir Simulator) do programa da CMG (Computer Modelling Group), vers?o 2010.10, onde as intera??es entre os par?metros operacionais, estudados em um modelo homog?neo com caracter?sticas de reservat?rios semelhantes aos encontrados no Nordeste Brasileiro, foram observadas. Os resultados obtidos neste estudo mostraram que os melhores fatores de recupera??o ocorreram para n?veis m?ximos do percentual de solvente injetado e da dist?ncia vertical entre os po?os. Observou-se tamb?m que o processo ser? rent?vel dependendo do tipo e do valor do solvente injetado