CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O projeto aerodinÃmico de um rotor eÃlico visa a otimizaÃÃo dos parÃmetros de funcionamento, para que este forneÃa uma maior eficiÃncia no regime de operaÃÃo em que à utilizado. O presente trabalho consiste na criaÃÃo de um software em linguagem C++, por meio do ambiente de desenvolvimento integrado C++Builder, atravÃs de um mÃtodo clÃssico de projeto de turbinas eÃlicas baseado na Teoria do Momento do Elemento de Pà (BEM). O software fornece ao usuÃrio dados geomÃtricos de construÃÃo, como curvas de afilamento e torÃÃo da pà com base nos dados dos aerofÃlios utilizados. A anÃlise da curva de potÃncia à feita e mostrada atravÃs de um grÃfico caracterÃstico. O software prediz as alteraÃÃes de desempenho devido Ãs perdas pela ponta e pela raiz da pÃ, e tambÃm informa, entre outras coisas, a distribuiÃÃo das cargas mÃximas ao longo da mesma, de acordo com a faixa de operaÃÃo desejada pelo usuÃrio. A potÃncia fornecida pelo aerogerador pode ser calculada atravÃs de dados de velocidade dos ventos. / The aerodynamic design of a wind rotor aims to optimize the operating parameters, so that this provides a more efficient system operation in which it is used. This work consists in creating a software in C + + language through the integrated development environment C + + Builder, via a classic method of wind turbines design based on the Blade Element Momentum Theory (BEM). The software provides the user with geometric data for building, such as curved taper of the blade and torsion based on the airfoils data used. The power curve analysis is performed and displayed via a characteristic plot. The software predicts performance changes due to losses by the tip and the root of the blade, and also shows, among other things, the distribution of maximum loads along the blade, in the operating range desired by the user. The power delivered by the turbine can be calculated using wind speed data.

A textura tem posição de destaque na qualidade da carne, podendo ser considerada como a característica sensorial de maior influência na aceitação por parte dos consumidores. Nesse contexto, as técnicas de determinação da textura da carne são de extrema importância. Assim, o objetivo desta dissertação foi o estudo comparativo de três técnicas de determinação da força de cisalhamento de carnes, utilizando-se dois equipamentos diferentes: o Warner-Bratzler Shear com sua lâmina padrão e um Texturômetro modelo TAXT2i (SMS) com duas lâminas de espessuras diferentes (3,05 e 1,01 mm), com a intenção de se obter correlações entre as diferentes técnicas utilizadas. Foram determinadas as forças de cisalhamento em seis cortes cárneos (5 bovinos e 1 suíno) com a finalidade de se obter as correlações numa ampla faixa de força de cisalhamento. Outras análises (Composição química, Perdas de água por cozimento e Microestrutura) foram realizadas para complementar as informações dos efeitos das três técnicas utilizadas sobre as respectivas respostas. Os dados obtidos nos testes de cisalhamento foram submetidos a uma análise descritiva visando determinar as variações entre os resultados de cada corte. A composição química, a microestrutura e as perdas de água foram utilizadas para explicar possíveis causas das variações. Foram feitas análises de regressão, obtendo-se modelos de correlação entre os dados obtidos com o Warner-Bratzler Shear e o texturômetro com as duas lâminas estudadas. Os resultados obtidos com Texturômetro utilizando-se lâmina de 3 mm superestimaram os resultados, indicando menor maciez do que as outras técnicas. Não se observou relação entre a composição química e a perda de água por cozimento com a textura das carnes. Entretanto, os resultados das análises com microscopia eletrônica de varredura permitiram explicar a variabilidade dos resultados da força de cisalhamento. / Texture has a prominent position on the quality of meat, and it can be considered the most influential sensory characteristic on consumers\' acceptance. In this sense, the techniques for texture determination of meat are very important. Thus, the aim of this dissertation was a comparative study of three techniques of determination of shear force of meat, using two different equipments: Warner-Bratzler Shear, with its standard blade; and the Texturometer TAXT2i, with two blades with different thicknesses (3.05 and 1.01 mm), for obtaining correlations between these different techniques. The shear forces were determined in six meat cuts (5 bovines and 1 swine) allowing correlations over a wide range of shear force. Other analyzes (chemical composition, water losses during cooking and microstructure) were performed to supplement the information of the effects of three techniques on shear force results. The data obtained in the shear tests were subjected to a descriptive statistical analysis in order to determine variations between the results for each cut. The chemical composition, microstructure and water losses were used to explain the possible causes of variations. Regression analyzes were performed and linear models of correlation between the data obtained with Warner-Bratzler Shear and the two blades texturometer were established. The results obtained with the 3 mm blade texturometer overestimated the results, suggesting lower softness than the other techniques. There was no relationship between the chemical composition and water loss during cooking with the meat texture. However, the results of analysis with scanning electron microscopy allowed explain the variability of the results of shear force.

Visando determinar os valores ótimos para o processo de serramento de anéis bobinados de filme metalizado ultrafino de alumínio com dielétrico de poliéster a partir das condições atuais do processo de fabricação de capacitores pela empresa Epcos do Brasil, realizou-se a avaliação de diferentes tipos de serras circulares variando-se a velocidade de rotação (n) e o tempo de corte (tc). Desenvolvido projeto de experimento desses três fatores a fim de obter o resultado das interações entre eles quanto à resistência de isolamento (Riso) das peças cortadas. A serra de 160 dentes de metal-duro com revestimento de filme de carbono tipo diamante (DLC) apresentou os melhores resultados quanto à “Riso” acima de 0,378 G e quanto ao número de peças com valor abaixo deste. Constatou-se que “n” não influencia significativamente para a distribuição de “Riso”; porém, gera menos peças abaixo do especificado. Já “tc” não influencia significativamente o processo. Quanto ao tipo de dente, o perfil reto obteve melhor resultado para lâminas de serra com 80 dentes e perfil curvo para lâminas com 160 dentes. Já a espessura da lâmina não influenciou de forma expressiva o processo. A lâmina de aço-rápido apresentou adesão de alumínio na lateral do corpo da serra e, consequentemente, adesão de material na superfície de corte. As lâminas de metal-duro sem revestimento apresentaram falhas no filme metalizado por causa do atrito gerado entre a superfície de corte e a lateral da lâmina; esse inconveniente é eliminado quando ela é revestida com filme DLC apresentando melhorias quanto à “Riso” das peças para “n” menores. Também houve adesão de alumínio na parte inferior do dente devido a uma delaminação da camada de filme DLC. / In order to determine the optimal values for the sawing process of wound rings of metalized ultra-thin film with dielectric of polyester from current conditions of capacitor manufacturing process by Epcos company in Brazil, it was performed the evaluation of different types of circular saws varying the rotational speed (n) and the cutting time (tc). Developed experiment design methodology for these three factors in order to get the result of the interactions between them regarding to the insulation resistance (Riso) of cut parts. Through the analysis of the main effects, the cemented carbide saw with 160 teeth and diamond-like carbon (DLC) film coating showed the best results in terms of "Riso" above 0,378 G and regarding to the number of parts with value below the specified. It was found that "n" does not influence significantly the distribution of "Riso"; however, generates fewer parts below the specified. Now "tc" does not significantly influence the process. Regarding the tooth type, straight profile obtained better results for saw blades with 80 teeth and curved profile for blades with 160 teeth. However the thickness of the blade did not influence significantly the process. The high speed steel blade presented adhesion of aluminum on the side of the saw body and, consequently, adhesion of material on the cutting surface. The cemented carbide blades uncoated presented failures on metalized film because of the friction generated between the cutting surface and the side of the blade; this drawback is eliminated when it is coated with DLC film presenting improvements to the parts "Riso" for lower "n". There was also aluminum adhesion on the bottom of the tooth due to a delamination of the DLC film layer.

As espécies nativas que compõem os ecossistemas pastoris dos países do Cone sul da América do Sul, são o principal substrato forrageiro, e sustentam a produção pecuária há muitos anos nesses locais. No entanto, o cenário atual é de diminuição na área desse tipo de pastagem e normalmente os remanescentes estão degradados pelo superpastejo. Portanto, é cada vez mais urgente a necessidade do lançamento de novas cultivares de gramíneas forrageiras que sejam adaptadas aos mais diversos ambientes para utilização como formadoras de pastagens cultivadas ou ainda como agente recuperador de áreas degradadas. O objetivo deste trabalho foi comprovar o valor agronômico de uma progênie híbrida intraespecífica selecionada de Paspalum notatum em dois ambientes distintos, por dois anos para posterior utilização dos genótipos superiores em novas etapas do programa de melhoramento genético de forrageiras. Foi possível observar a existência de variabilidade para os principais caracteres forrageiros avaliados. A variável matéria seca total (MST) demonstrou que a maioria dos híbridos testados apresentou adequada produção de forragem, sendo que grande parte produziu mais que a cultivar Pensacola em ambos os locais testados. Alguns dos melhores genótipos para MST também estavam entre os melhores para massa seca de lâminas foliares (MSF), o que demonstra que este material, provavelmente, produz forragem com adequado valor forrageiro para a produção animal. As diferentes formas de distribuição das folhas sugere que o manejo adotado deve ser adequado de acordo com essa característica. Grande parte dos genótipos testados foi capaz de manter uma alta densidade de perfilhos, demonstrando que são capazes de persistir ao longo do tempo após estabelecida a pastagem. A MSF é a característica que mais se associa com a MST, o que sugere que, ao selecionar genótipos de P. notatum para produção de MST, secundariamente estará ocorrendo seleção para MSF, economizando tempo no processo de avaliação. Assim pode-se afirmar que a produção da MST pode ser utilizada diretamente para seleção de genótipos superiores e os híbridos de reprodução apomítica que apresentaram maiores rendimentos para esta variável são passíveis de registro junto ao ministério da agricultura pecuária e abastecimento. / Native species that compose the natural grassland ecosystem of the countries that belong to the Pampa Biome and Atlantic Forest Biome, are the main forage substrate, and sustain livestock production for many years in these locations. However, the current scenario is a decrease in the area of this type of pasture, and massive degradation normally occurs where these still resist. Therefore, there is an urgent need to launch new varieties of forage grasses that are adapted to different environments for use as forming cultivated pastures, or as agent for recovery of degraded areas. The aim of this study was to demonstrate the agronomic value of an intraspecific hybrid progeny of Paspalum notatum selected in two different environments for two years to further use of superior genotypes in new stages of breeding of forage program. It was possible to observe the existence of variability for the major forage characters evaluated. The total dry matter variable (MST) demonstrated that most hybrids tested showed adequate forage production, much of which has produced more than cultivar Pensacola tested in both locations. Some of the best genotypes for MST were also among the best for dry mass of leaf blades (MSF), which demonstrates that this material probably produces forage with adequate forage value for livestock production. The different form of distribution of the leaves suggests that management adopted should be appropriate according to this characteristic. Most of the tested genotypes were able to maintain a high tiller, indicating that they are able to persist after grazing is established. MSF is the characteristic most frequently associated with the MST, suggesting that, when selecting genotypes of P. notatum for MST, will be occurring secondarily a selection for MSF, saving time in the evaluation process. Thus it is possible to affirm that the production of MST can be used directly to select genotypes, and hybrids of apomictic reproduction, which showed higher yields for this variable, are eligible for registration with the ministry of agriculture and livestock supplies.

Rotating blades, which are the most critical components of any turbo-machinery, need to be designed to withstand forced vibrations due to accidental tip rub impact against inner surface of casing. These vibrations are typically dependent on operating conditions and geometric parameters. In the current study, a rotor test rig with a maximum tip speed capability of 144 km/hr has been developed for studying the dynamic behavior of representative jet engine compressor blades actuated by the closure of clearance between the tip of a given rotating blade and a sector of the inner lining of the casing. Ten different blade profiles are chosen in the present research. The blades are obtained by lofting NACA GOE123 airfoil cross-section along different stacking axes. Rotor test rigs which simulate transient dynamic events require high frequency data acquisition systems like slip ring arrangement or telemetric transmission. While slip rings introduce noise into the signal, the telemetric transmission works out to be rather expensive. To circumvent the stated shortcomings of data acquisition systems, a novel rotor-mounted data acquisition system has been implemented here which captures dynamic strains in vibrating blades during operation. The current data acquisition system can store data for duration of five seconds with a sampling rate of 35 kHz. It has been calibrated with four standard tests, and provides a simple and efficient mode of data capturing. Three blades with airfoil sections (a flat beam-type blade of uniform rectangular cross-section, a blade with twisted cross-sections stacked along a straight line, and a blade similar to the latter but with a curved stacking axis) are tested under controlled rub conditions at four different speeds. The maximum test speed is restricted to 800 rpm for reasons of safety although the set-up is designed to operate up to a maximum speed of 2000 rpm. For each of the rotor speeds, a blade is tested for three to four different stagger angles in the range of 0o-30o. By plotting the RMS values of measured dynamic responses with respect to stagger angle for a given rotor speed, it has been observed, perhaps for the first time in published literature, that a stagger angle of around 20o yields the maximum RMS value of strain response. A major objective of the current study has been to utilize the data generated in the tip rub impact tests for validating a predictive numerical model of the test set-up using explicit finite element analysis. To this end, a finite element model of the rotor rig inclusive of a rotor with two blades and the static frame structure is developed and analyzed using an explicit LS-DYNA solver. This model is calibrated with the test results of the three blade designs described above. In particular, it has been shown that the frequency contents of the measured dynamic strain responses agree quite well with frequencies obtained from the numerically computed responses. It has been found in the experimental responses that a given blade vibrates with two main frequencies: one corresponding to the first natural frequency of the rotor-blade system during the tip-rubbing phase (which lasts until the blade tip is in contact with the rub element which is a sector of the circular casing), and another corresponding to the first natural frequency of the blade when it vibrates freely without its tip being in contact with the rub-liner of the casing. A shortcoming of the current modeling approach is its inability to realistically represent the damping behaviors observed in the tests. For reasons of computational efficiency and consistent with the fact that there was no perceptible damage in the tested blades, an elastic constitutive behavior is specified for the blades, while the sacrificial PVC rub-liner is assumed to behave elasto-plastically. A limited study has also been carried out by assigning an elasto-plastic constitutive model to one of the blades previously represented with elastic properties only, and although incipient yielding is observed in a highly localized region at the tip of a blade (which can also be a numerical artifact), the responses under the two material behavior considerations (i.e. elastic and elasto-plastic) are found to be nearly same. Finally, this validated modeling approach is applied to the study of blades of ten distinct geometric profiles (including the three configurations already considered) at a speed of 800 rpm and the resonant speed of a given blade. Comparisons are made between the relevant responses (such as time-histories of root strain, shaft torque, blade axial displacement, bearing load and rub force) of nine blades with airfoil cross-sections (leaving aside the results for the first blade of rectangular cross-section which is only of academic interest). Based on this study, of all the blade designs, it has been found that the curve-stacked airfoils exhibit better ‘Rub-tolerant’ behavior. Both experimental and simulation results have predominantly proven the fact that adding curvature to a straight stacked blade through curve-stacked or bow result in reducing the rub induced vibration. While sweep and bow provide some aerodynamic advantages, they are not much helpful in containing the vibrations to a sustainable extent.

L’objectif de ces travaux est de prédire la stabilité dynamique d’un moteur d’avion de type turbofan, lors de contacts légers entre l’extrémité des aubes et le carter en regard. Une voix d’amélioration des performances des turboréacteurs d’avion consiste, en effet, à réduire les jeux entre les extrémités des aubes en rotation et le carter. Réduction qui s’accompagne d’une augmentation des possibilités de contact entre ces parties tournantes et fixes pouvant conduire à des phénomènes vibratoires instables. La démarche proposée s’appuie sur un modèle hybride qui introduit de manière simplifiée une roue aubagée et un carter flexible à un modèle de ligne d’arbres. Une formulation dite 3D du contact a également été implémentée, elle intègre la cinématique des différents organes du modèle et introduit de manière précise la géométrie locale de la zone de contact. Le comportement du modèle lors de contacts aubes-carter est alors étudié en distinguant les analyses menées en supposant un contact permanent et celles autorisant l’intermittence des contacts. Les résultats obtenus mettent en évidence l’importance des couplages introduits dans l’apparition des phénomènes instables et la pertinence de la formulation 3D dans la prédiction de la stabilité du système. / This work aims to predict the dynamic stability of a turbofan engine submitted to light contacts between blade tips and casing. Reducing the clearance between the rotating blades and the casing improves indeed the performances of turbomachines ; however, it also increases the possible contacts between rotating and stationary parts, which can cause unstable dynamic behavior. The approach is based on a hybrid model which introduces a simplified bladed wheel and a flexible casing to a rotor-shaft model. A 3D contact formulation has also been implemented ; it considers the model kinematic and introduces the local geometry of the contact area. The model behavior with blade-to-casing contacts is analyzed through two approaches : the first one assumes permanent contacts while the other one allows contact intermittence. The results highlight the importance of couplings in the outbreak of unstable phenomena and the relevance of the 3D contact formulation in predicting the stability of the system.

This master‘s thesis deals with small water power plant Beneš. The first part of the thesis tries to find causes of low efficiency of this power plant. The second part contains suggestions of construction changes for increasing of efficiency – design of new runner blades and basic parameters of new distributor.

La société SIAT-BRAUN, premier de sciage résineux de France, présente une problématique industrielle liée à ses outils de coupe. Les scies débitant le bois doivent être les plus fines possibles afin de préserver la matière d'oeuvre, mais aussi très robustes pour supporter les conditions de coupe qui ne cessent de se durcir. La maîtrise de la matière première ainsi que des paramètres de réglage des machines sont des conditions sine-qua-none du bon travail des outils. Ainsi, nous arrivons à des situations limites où les règles actuelles ne répondent pas correctement aux exigences recherchées. Le mémoire comporte une étude technico-économique de la scierie et de son évolution, ainsi que du matériau bois employé. L'explication du fonctionnement de la ligne de sciage de l'entreprise, une des plus modernes, d'Europe, achève cette présentation.L'analyse des connaissances actuelles englobe les différents paramètres et calculs relatifs à l'usinage du bois, ainsi que les divers éléments composant une scie circulaire et ses géométries associées. Les interactions entre tous ces éléments sont aussi présentées. Le métier d'affûteur, personne en charge de la maintenance des outils et garante de leur bon fonctionnement, est présenté ainsi que des améliorations mises en place au niveau de la méthode ainsi que des machines de l'atelier.Pendant cette thèse, de nombreuses améliorations ont été réalisées sur les différents outils de coupe, afin de répondre aux exigences de la production en gardant une fiabilité la plus importante possible. La dernière partie proposera les améliorations restant à valider sur l'adéquation entre les matériaux et la géométrie angulaire des scies circulaires / SIAT-BRAUN is the largest industrial sawmill in France and faces typical industrial challenges with its sawing technologies.Wood saws must be as thin as possible, in order to maximize yield and save raw material and robust enough to endure tougher and tougher sawing conditions. Good raw material control and optimized machine parameterization are critical to ensure good results. The current theoretical background, does not always match these requirements and we are therefore always testing its limits.An economical and technical analysis of the sawmill and its evolution makes up the first part of this thesis. We will be detailing the key operations of one of the most modern sawmill in Europe.Current knowledge analysis must include the various parameters and calculations necessary to machine wood, as well as the different blade components and their geometric specifications. We will discuss the interactions between these elements. The job of the filer (the person in charge of tool maintenance) will also be discussed, as well as several improvements implemented in the workshop.Many improvements have been suggested and implemented while working on this thesis, in order to react to production needs while preserving reliability. In the last section of this thesis we will discuss several improvements that remain to be validated on how to best match appropriate cutting materials and blade geometry

This degree project in applied physics studies the tip gap flows over the rotor blades of a high-pressure turbine. The rotor blade used in the study has an improved design that utilizes both a cavity tip and an uneven profiling to reduce turbine loss. The designed rotor blade is shown to admit a 21% lower leakage mass flow rate across the tip gap than a reference rotor blade with a flat tip. By studying the designed rotor blade using transient CFD, the flow field of the tip gap region has been studied through one blade passage. The flow field characteristics of particular interest are the leakage mass flow rate across the tip gap region, which is proportional to turbine loss, and the characteristic vortices that reside within the cavity tip. By using post-processing scripts, the leakage mass flow rate has been calculated for every time step across one blade passage, showing a strong time dependence. The characteristic vortices are found using two different vortex detection algorithms, and their respective vorticity magnitude is shown to depend on the leakage mass flow rate. The simulation shows that the vorticity magnitude is increasing above a threshold of leakage mass flow rate, and that it is decreasing under this threshold. This effect is shown to destabilize the leakage mass flow rate, increasing its amplitude over its period of one blade passage.

Genom 2000-talets teknologiska framåtskridande finns förhoppningen om att en dag kunna skapa ett artificiellt medvetande, ett objekt med förmågan att tänka på att den tänker och med en egen fri vilja. Om eller när detta blir verklighet ställs frågorna vad exakt det är som människan har skapat och hur vi ska förhålla oss till det skapade. Dessa frågor ligger till grund för vad denna uppsats, genom ett innehållsanalytiskt tillvägagångssätt, undersöker, med syftet att analysera hur gestaltningen på film av artificiell intelligens (A.I.) kan förstås i relation till en kristen mytologi. Utifrån filmmanusen till The Imitation Game (2014) och Blade Runner 2049 (2017) analyseras de filmiska representationerna av A.I. med ett teologiskt avbildsbegrepp som dialogiskt förstoringsglas. Uppsatsen finner att fiktionen i detta sammanhang lyfter fram att strävan efter att skapa A.I. som avbild pekar på ett mänskligt sökande efter både närhet och kärlek.