The current demands for higher performance in gas turbine engines can be reached by raising combustion temperatures to increase thermal efficiency. Hot combustion temperatures create a harsh environment which leads to the consideration of the durability of the combustor and turbine sections. Improvements in durability can be achieved through understanding the interactions between the combustor and turbine. The flow field at a combustor exit shows non-uniformities in pressure, temperature, and velocity in the pitch and radial directions. This inlet profile to the turbine can have a considerable effect on the development of the secondary flows through the vane passage. This thesis presents a computational study of the flow field generated in a non-reacting gas turbine combustor and how that flow field convects through the downstream stator vane. Specifically, the effect that the combustor flow field had on the secondary flow pattern in the turbine was studied. Data from a modern gas turbine engine manufacturer was used to design a realistic, low speed, large scale combustor test section. This thesis presents the results of computational simulations done in parallel with experimental simulations of the combustor flow field. In comparisons of computational predictions with experimental data, reasonable agreement of the mean flow and general trends were found for the case without dilution jets. The computational predictions of the combustor flow with dilution jets indicated that the turbulence models under-predicted jet mixing. The combustor exit profiles showed non-uniformities both radially and circumferentially, which were strongly dependent on dilution and cooling slot injection. The development of the secondary flow field in the turbine was highly dependent on the incoming total pressure profile. For a case with a uniform inlet pressure in the near-wall region no leading edge vortex was formed. The endwall heat transfer was found to also depend strongly on the secondary flow field, and therefore on the incoming pressure profile from the combustor. / Master of Science

In the United States, natural gas turbine generators account for approximately 7% of the total primary energy consumed. A one percent increase in gas turbine efficiency could result in savings of approximately 30 million dollars for operators and, subsequently, electricity end-users. The efficiency of a gas turbine engine is tied directly to the temperature at which the products of combustion enter the first stage, high-pressure turbine. The maximum operating temperature of the turbine components’ materials is the major limiting factor in increasing the turbine inlet temperature. In fact, current turbine inlet temperatures regularly exceed the melting temperature of the turbine vanes through advanced vane cooling techniques. These cooling techniques include vane surface film cooling, internal vane cooling, and the addition of a thermal barrier coating (TBC) to the exterior of the turbine vane. Typically, the performance of vane cooling techniques is evaluated using the adiabatic film effectiveness. However, the adiabatic film effectiveness, by definition, does not consider conjugate heat transfer effects. In order to evaluate the performance of internal vane cooling and a TBC it is necessary to consider conjugate heat transfer effects. The goal of this study was to provide insight into the conjugate heat transfer behavior of actual turbine vanes and various vane cooling techniques through experimental and analytical modeling in the pursuit of higher turbine inlet temperatures resulting in higher overall turbine efficiencies. The primary focus of this study was to experimentally characterize the combined effects of a TBC and film cooling. Vane model experiments were performed using a 10x scaled first stage inlet guide vane model that was designed using the Matched Biot Method to properly scale both the geometrical and thermal properties of an actual turbine vane. Two different TBC thicknesses were evaluated in this study. Along with the TBCs, six different film cooling configurations were evaluated which included pressure side round holes with a showerhead, round holes only, craters, a novel trench design called the modified trench, an ideal trench, and a realistic trench that takes manufacturing abilities into account. These film cooling geometries were created within the TBC layer. Each of the vane configurations was evaluated by monitoring a variety of temperatures, including the temperature of the exterior vane wall and the exterior surface of the TBC. This study found that the presence of a TBC decreased the sensitivity of the thermal barrier coating and vane wall interface temperature to changes in film coolant flow rates and changes in film cooling geometry. Therefore, research into improved film cooling geometries may not be valuable when a TBC is incorporated. This study also developed an analytical model which was used to predict the performance of the TBCs as a design tool. The analytical prediction model provided reasonable agreement with experimental data when using baseline data from an experiment with another TBC. However, the analytical prediction model performed poorly when predicting a TBC’s performance using baseline data collected from an experiment without a TBC. / text

his diploma thesis deals with hydraulic design of vane wheel impeller of wide range Francis turbine; in addition to hydraulic calculation it consists overview of used theory, modelling in SolidWorks and computing in Fluent.

The purpose of this research was a proof of concept using a fan motor stator as transducer to monitor motor rotor and attached axial fan for mechanical motion. The proof was to determine whether bearing faults and fan imbalances could be detected in vane-axial fans using Motor Electrical Signature Analysis (MESA). The data was statistically analyzed to determine if the MESA systems could distinguish between baseline conditions and discrete fault frequencies for the three test conditions: bearing inner race defect, bearing outer race defect, and fan imbalance. The statistical conclusions for these proofs of concept were that MESA could identify all three faulted conditions.

A presente pesquisa apresenta resultados de uma série de ensaios de palheta de laboratório, com a finalidade de determinar a resistência não drenada de um solo residual compactado. Durante o ensaio foram realizadas medições continuas de sucção com uso de um tensiômetro de alta capacidade, disposto na base dos corpos de prova, sendo este procedimento inédito. O objetivo secundário do estudo é a avaliação de aspectos relacionados com a variação da resistência e sucção quando a distância do tensiômetro de alta capacidade é modificada com relação à superfície inferior do plano de ruptura pré-estabelecido. Para a realização destes experimentos foram modificados e adaptados equipamentos de laboratório. O estudo foi realizado com um solo residual de gnaisse compactado obtido do antigo campo experimental da Escola Politécnica da Universidade de São Paulo. O estudo constata que o valor medido da resistência não drenada é afetado pela proximidade do tensiômetro a palheta. / This research presents results of a series of mini-vane tests in order to determine the undrained shear strength of a residual compacted soil. During the tests and for the first time, continuous measurement of suction has been made using a high capacity tensiometer placed at the base of the specimen. The secondary aim of this study is to evaluate aspects related to resistance and suction variation when the distance of the high capacity tensiometer is modified in relation to the lower pre-set failure surface. For this reason laboratory equipments were modified and adapted in order to perform the study. The tests were performed with a compacted residual soil of gneiss obtained from the experimental site of the Polytechnical School of the University of São Paulo. The study showed that the undrained shear strength is affected when the vane are closer to the tensiometer.

O presente trabalho reúne elementos teóricos e experimentais envolvendo os principais fenômenos hidráulicos causadores de danos em bombas hidráulicas de fluxo radial de grande porte. A preocupação do texto está centrada em proporcionar um aprofundamento técnico acerca destes fenômenos hidráulicos de cavitação, a fim de contribuir na análise e solução de problemas em sistemas de bombeamento. Além disso, este trabalho tem a pretensão de transmitir alguma experiência prática fornecida por um evento em que foi detectada a ocorrência de dois destes fenômenos hidráulicos simultâneos em um sistema de bombeamento e a partir disso, realizou-se a análise completa deste evento, incluindo as propostas de solução aos problemas encontrados, as análises técnica e econômica das alternativas de solução e a análise após a implantação da proposta escolhida. O texto apresenta também uma grande quantidade de gráficos e figuras que buscam facilitar a compreensão das definições e das análises dos fenômenos hidráulicos, além de exemplificar os danos típicos dos fenômenos pela visualização direta destes danos nas bombas. / This work presents theoretical and experimental data on the principal hydraulic phenomena responsible for damage in high loaded radial flow hydraulic pumps. The main objective is to provide a technical overview in order to contribute for the analysis and solution on these cavitation pumping systems problems. In addition this work intends to transmit practical experience through a “study of case" where two simultaneous of these hydraulic phenomena were detected. The complete analysis of technical and economical aspects of the alternatives solutions is presented including a great amount of graphs and illustrations that better explain the phenomena of cavitation in hydraulic pumps.

O conceito de um motor rotativo de palhetas é apresentado e o modelo que opera similar aos motores recíprocos dois tempos é analisado. Este motor é formado por estator cilíndrico, rotor descentralizado, palhetas radiais e tampas laterais, similar aos compressores de palhetas radiais. Parâmetros geométricos estão definidos para que o motor possua características similares a dois motores recíprocos comerciais igualmente modelados. Suas geometrias estão detalhadas, assim como a modelagem termodinâmica e suas hipóteses, as quais devido ao caráter comparativo do trabalho não têm grande influência no alcance dos objetivos. Em relação aos motores recíprocos, o novo conceito prospecta algumas vantagens: maior compacidade; menor nível de vibrações; maior facilidade de alteração da razão de compressão; possibilidade de produção e montagem em módulos; e devido a todas estas, as maiores possibilidades para o projeto, fabricação, montagem e operação dos motores. Para melhor entendimento de algumas tendências relativas a estas vantagens, a sensibilidade dos parâmetros geométricos é estudada, com variações nos diâmetros do estator e do rotor, na espessura do rotor e das palhetas, na excentricidade entre rotor e estator, e no número de palhetas do conceito. Este estudo demonstra características únicas do motor rotativo de palhetas, dentre elas, a variação da espessura do rotor se destaca por proporcionar a alteração do tamanho do motor sem modificar os demais aspectos. A excentricidade entre o rotor e estator demonstra grande potencial na capacidade de alterar a razão de compressão do equipamento, inclusive podendo ser modificada após a construção do motor ou até mesmo durante sua operação. Também se destaca o número de palhetas, o qual tem influência direta sobre a curva de torque do ciclo e a efetividade do posicionamento das janelas de admissão e exaustão. Com isto, é concluída a caracterização da geometria e do funcionamento do motor rotativo de palhetas, obtendo uma boa base para as próximas etapas de seu desenvolvimento. / The concept of a rotary vane engine is presented and the model that operates similar to twostroke reciprocating engines is analyzed. This engine is formed by a cylindrical stator, decentralized rotor, radial vanes and side housing plates, similar to the radial vane compressors. Geometrical parameters are defined so that the motor has similar characteristics to two commercial reciprocating engines also modeled. Their geometries are detailed, as well as the thermodynamic model and its assumptions, which due to the comparative nature of the work do not have significant influence in achieving the objectives. With respect to reciprocating engines, the new concept is prospecting some advantages: higher compactness; lowest level of vibration; ease of adjustment of compression ratio; possibility of manufacture and assembly in modules; and due to all these, the numerous possibilities to the design, manufacture, assembly and operation of the engines. For a better understanding of some these advantages trends, the sensitivity of geometric parameters are studied, with variations in the diameters of the stator and rotor, in the thickness of the rotor and the vanes, in the eccentricity between rotor and stator, and in the number of vanes of the concept. This study demonstrates unique rotary vane engine characteristics, among them, the range of rotor thickness stands out for providing a change in engine size without changing other aspects. The eccentricity between the rotor and stator shows great potential for the ability to change the compression ratio of the equipment and can be modified even after the construction or even during operation of the engine. It also highlights the number of vanes, which has a direct influence on the torque curve of the cycle and the effectiveness of the positioning of inlet and exhaust ports. Therewith, the characterization of rotary vane engine geometry and operational design is complete, obtaining a good basis for its next development stages.

O ensaio de palheta de campo em material siltoso levanta problemáticas relacionadas à sua execução e à interpretação dos resultados. O presente trabalho apresenta uma modelagem em poroelasticidade do ensaio de palheta. O modelo de ensaio é definido pelo problema de rotação de um cilindro infinito em um solo poroso. A solução do problema é buscada adotando um comportamento poroelástico não linear fictício tal que a resposta é localmente equivalente àquela do comportamento plástico perfeito. O modelo considera que a rotação do cilindro gera deformações volumétricas não desprezíveis e que a solução fechada de poropressão é garantida por um módulo de cisalhamento equivalente. As soluções do campo de tensões e deformações descritas por equações analíticas são obtidas numericamente por meio do método de diferenças finitas. O modelo é avaliado através de uma comparação com os resultados de simulação em elementos finitos e de solução do modelo com o uso de software de álgebra computacional. Os critérios de Tresca e de Drucker-Prager são considerados nas avaliações. As condições de drenagem foram estudadas através da curva característica de drenagem no espação grau de drenagem U versus velocidade normalizada V. A influência da rigidez e da resistência do material sobre o fenômeno de dissipação foram interpretados no mesmo espaço U ×V . Também foi demonstrado que a dissipação é sensível à definição da zona de influência. O parâmetro numérico de discretização do domínio para o método de diferenças finitas para a obtenção de resultados de boa precisão foi identificado. O modelo foi aplicado para a modelagem do ensaio de palheta em resíduo de zinco e para a interpretação dos resultados desse ensaio. Demonstrou-se que o modelo proposto permite a identificações dos padrões de ensaio que garantem os comportamentos desejados, além de possibilitar o estudo da sensibilidade do processo de dissipação em relação à rigidez e resistência do material. / The Field Vane Test in silty materials raises problematics related to its execution and interpretation of results. The work presents a model for the vane test based on poroelasticity. The modeling of the test is characterized by the problem of the rotation of an infinite cylinder in a porous soil. The solution of the problem is sought by adopting a fictitious non-linear poroelastic behavior such that the answer is locally equivalent to the one corresponding to a perfect plastic behavior. The revised model assumes that rotation of the cylinder does generate volumetric deformation which one is not negligible and the close form of solution for pore pressure is guaranteed by an equivalent shear modulus. The solutions of stresses and displacement field are obtained numerically using the finite difference method. The model is evaluated for materials characterized by two criteria Tresca and Drucker-Prager through a comparison of results obtained by simulation in finite element model and by simulation using computer algebra software. The drainage conditions have been studied through the drainage characteristic curve U ×V . The influence of the stiffness and strength of the material on the dissipation phenomena were interpreted in the same space U ×V . It was also demonstrated that the dissipation process is sensitive to the definition of the influence zone. The numerical parameters to obtain good precision results were identified. The model was applied to the modeling Vane Test in zinc residue and the interpretation of experimental results. It has been shown that the proposed model allows the identification of test patterns that ensures the desired drainage behavior and allows the study of the sensitivity of the dissipation process for stiffness and strength of the material.

A presente pesquisa apresenta resultados de uma série de ensaios de palheta de laboratório, com a finalidade de determinar a resistência não drenada de um solo residual compactado. Durante o ensaio foram realizadas medições continuas de sucção com uso de um tensiômetro de alta capacidade, disposto na base dos corpos de prova, sendo este procedimento inédito. O objetivo secundário do estudo é a avaliação de aspectos relacionados com a variação da resistência e sucção quando a distância do tensiômetro de alta capacidade é modificada com relação à superfície inferior do plano de ruptura pré-estabelecido. Para a realização destes experimentos foram modificados e adaptados equipamentos de laboratório. O estudo foi realizado com um solo residual de gnaisse compactado obtido do antigo campo experimental da Escola Politécnica da Universidade de São Paulo. O estudo constata que o valor medido da resistência não drenada é afetado pela proximidade do tensiômetro a palheta. / This research presents results of a series of mini-vane tests in order to determine the undrained shear strength of a residual compacted soil. During the tests and for the first time, continuous measurement of suction has been made using a high capacity tensiometer placed at the base of the specimen. The secondary aim of this study is to evaluate aspects related to resistance and suction variation when the distance of the high capacity tensiometer is modified in relation to the lower pre-set failure surface. For this reason laboratory equipments were modified and adapted in order to perform the study. The tests were performed with a compacted residual soil of gneiss obtained from the experimental site of the Polytechnical School of the University of São Paulo. The study showed that the undrained shear strength is affected when the vane are closer to the tensiometer.

Horizontally mounted compressors offer the advantage of reduced height in central air-conditioning units but prove difficult to produce economically due to costs associated with the manufacture of acceptable lubrication systems for the compressors. This study develops an effective, affordable oil pump for use on a horizontal compressor. Concepts are proven through testing of prototype assemblies. Test results drive modifications for future prototypes, and prototypes demonstrating adequate performance are modified for ease of manufacture. Research in this study proves that the most suitable design results from a modification of a rotating vane pump. The pump’s modifications enable it to pump oil in the same direction, regardless of the direction of shaft rotation and to prime itself when totally dry of oil. However, extensive use of horizontal compressors hinges upon the development of a satisfactory suspension system.