O presente trabalho apresenta uma metodologia de simulação numérica de perfis aerodinâmicos bidimensionais com foco na utilização para o projeto e otimização de pás e rotores de pequenas turbinas eólicas de eixo horizontal, bem como o emprego desses métodos em simulações nas quais efeitos de alta solidez do rotor e baixos números de Reynolds são avaliados. Essa metodologia inclui geração de malhas, seleção de métodos numéricos e validação, tendo as escolhas sido guiadas pelas práticas mais bem sucedidas na simulação de perfis aerodinâmicos, e foi aplicada na simulação dos aerofólios NACA 0012, S809 e SD7062. O código comercial ANSYS Fluent foi utilizado em todas as simulações. Na simulação de aerofólios isolados a altos números de Reynolds dos perfis NACA 0012 e S809, o modelo Transition SST (γ-Reθ) apresentou resultados mais próximos a dados experimentais do que aqueles apresentados pelo modelo k-ω SST para CL e CD, além de produzir resultados para CP que mostraram boa precisão quando comparados aos mesmos dados experimentais. Resultados de CL, CD, CF e CP são apresentados para 20 diferentes condições de operação às quais o perfil SD7062 foi submetido, com números de Reynolds variando entre 25.000 e 125.000. As distribuições dos dois últimos coeficientes sobre os dorsos do aerofólio evidenciam com clareza a presença e magnitude da bolha de separação laminar. Os coeficientes de sustentação e arrasto mostram o impacto negativo da presença da bolha nessa faixa de números de Reynolds. Além disso, nos casos simulados, o arrasto aumenta em função da diminuição do Re. Um design de pá produzido com o auxílio do código de otimização SWRDC, baseado em algoritmos genéticos, é apresentado. Três seções ao longo da envergadura dessa pá foram simuladas em uma bateria de 45 simulações, sob diversas condições de operação em função de solidez, ângulo de ataque e razão de velocidade de ponta de pá. Esses resultados mostram que a bolha de separação laminar se move na direção do bordo de ataque com o aumento da solidez, do ângulo de ataque e da TSR. Além disso, distribuições do CP mostram aumento de pressão em ambos os dorsos do perfil quando submetido aos efeitos da solidez, embora esses efeitos tenham sido responsáveis por um aumento na relação CL/CD nos casos estudados. / This thesis presents a methodology of two-dimensional airfoil simulation focusing on its application on the design and optimization of blades and rotors of small horizontal axis wind turbines, and its application in a set of numerical simulations involving high rotor solidity and low-Re effects. This methodology includes grid generation, selection of numerical methods and validation, reflecting the most successful practices in airfoil simulation, and was applied in the simulation of the NACA 0012, S809 and SD7062 airfoils. The ANSYS Fluent commercial code was used in all simulations. Results for the isolated NACA 0012 and S809 airfoils at high Reynolds numbers show that the Transition SST (γ-Reθ) turbulence model produces results closer to experimental data than those yielded by the SST k-ω model for CL and CD, having also produced CP plots that show good agreement to the same experimental data. Plots of CL, CD, CF and CP for the SD7062 airfoil are presented, for simulations at 20 different operating conditions. The CF and CP distributions evidence the negative impact of the laminar separation bubble in the range of Reynolds numbers evaluated. Results show that, for Re between 25,000 and 125,000, drag increases with decreasing Re. A blade design generated using the SWRDC optimization code, based on genetic algorithms, is presented. Three sections of the resulting blade shape were selected and were tested in a set of 45 simulations, under an array of operating conditions defined by solidity, angle of attack and TSR. Results show that the laminar separation bubble moves towards the leading edge with increasing solidity, angle of attack and TSR. Furthermore, CP plots show an increase in pressure on both surfaces when the airfoil is subject to solidity effects, although these effects show an increase in the lift-to-drag ratio at the conditions evaluated.

C-paper Abstract Title: Fluidity and Solidity in Marilynne Robinson’s Housekeeping Author: Linda Lindqvist The purpose of this essay is to show that fluidity and solidity constitute a central tension on all levels in Housekeeping, and how this tension leads to a choice of either a fluid or a solid lifestyle and view of the world. I focus on fluidity and solidity in gender roles, in memories, in dreams, in nature, and in different perceptions of reality. By taking a closer look at Ruth’s first-person narration (seeing fluidity as not resisting deformation, while solidity resists deformation), we find that the characters in Housekeeping have fluid and solid traits, but that there is no reality that allows mixed manifestations of these. This results in repression of either fluidity or solidity, which creates tension and feelings of loss. Ruth chooses a fluid lifestyle, thus her memories and dreams become mixed with her present, and this also leads her to become a transient, outside gender roles and traditional small town society. Transience in this novel questions all distinctions conventionally made between dream and reality; male and female. In conclusion, this essay highlights how tension between fluidity and solidity is generated on all levels in Housekeeping, and how this leads to either fluid or solid lifestyles since the characters follow a cultural code that dictates a choice between them.

Le développement de turbomachines à faible vitesse spécifique suscite actuellement une forte demande dans de nombreux domaines industriels. De nos jours, les ventilateurs centrifuges constituées d'une roue, d'un diffuseur et d'un canal de retour sont largement utilisés dans de nombreuses applications telles que l'automobile, l'aéronautique, appareils domestiques, etc. En raison de leur grande adaptabilité, ils peuvent fonctionner sur une large plage de débit en particulier avec une vitesse de rotation importante. Cependant, leur utilisation nécessite une meilleure compréhension de leur fonctionnement et notamment de l'interaction rotor-stator pour mieux les concevoir. L'objectif de cette étude est d'analyser et de quantifier l'influence de la solidité des aubes du diffuseur (ou serrage des profils) sur les performances aérauliques du ventilateur centrifuge. Une étude numérique et expérimentale a été menée pour analyser les performances d'un ventilateur centrifuge avec différents niveaux d'interaction rotor-stator. Différentes géométries de diffuseur ont été proposées dans le but de réduire les dissipations énergétiques liées aux phénomènes de recirculation et aux forces de viscosité. L'étude approfondie de la norme ISO 5801 et ISO 5167 a permis de dimensionner et réaliser le banc d'essai et les organes de mesures. Ces normes proposent des calculs et des spécifications qui nous ont permis de fixer des critères quant au choix des éléments du banc d’essai AERO2VACCUM. / Nowadays, centrifugal fans are widely used in many industrial applications such as automotive, aeronautic, vacuum cleaner, etc. Due to their high adaptability, they can operate over a wide flow range especially with high speed rotation. In order to reduce the impact on environment, centrifugal fan as other energy conversion system has to display a high efficiency. However, a better understanding of their working and of the rotor-stator interaction is required to enhance their design and to make them widely integrated in current applications. The purpose of this study is to analyze and to quantify the influence of the solidity vaned diffusers on the performance of a centrifugal fan. A computational study has been conducted to analyze the performance of a centrifugal fan under various levels of impeller-diffuser interactions. The objective was to understand the pressure recovery phenomena in each diffuser. Different geometries were proposed to reduce both separation flow phenomenon and viscous losses. The geometries are all composed with the same impeller and return channel, only the vaned diffusers differ; the trailing edges are maintained at the same position while the leading edges have different radial positions. The characterization of the fan has been realized by an experimental setup designed and built in agreement to the standards ISO 5801 and 516

The theme of this thesis is a financial analysis of the Ravak, Inc. from the view of external user for the period 2004 to 2009. In theoretical part of the thesis , there are defined meaning and importance of financial analysis, its users, information sources and methods of financial analysis. The practical part includes basic information about the company and application of theoretical knowledge to the financial data of Ravak, Inc. In another part of the work, the methods of financial analysis are applied to a selected group of competitors for the purpose of inter-company comparison. Conclusion contains evaluation of results and financial situation of company and their major competitors.

This thesis evaluates the financial situation of the company Vetropack Moravia Glass, joint-stock company in the time period of 2002 – 2006 by way of prime financial analysis methods. The thesis contains proposals of possible solutions and recommendations for an improvement of financial situation of the firm in future years.

This diploma work analyse financial situation on the basis of chosen methods of financial analysis in the copany form the years 2005 – 2008. It contains suggestions of possible solutions of recognized financial status, which will contribute to improvement of the financial situation in the firm in coming years.

This master’s thesis considers a financial strategy of a company by means of financial indices analysis. On the basis of properly chosen methods and their interpretation the work evaluates a financial health of the company, tries to identify weak points that should be lead up to possible problems in the future and to identify strong points that the company should built on. Financial analysis evaluates past, present and expected future of the company financial economy. It contains proposals and measures that help to eliminate or to maximally reduce negative events and lead up to an improvement of the company financial situation.

This master´s work deals with the evaluation of the financial situation in the company DEAS ltd. and it´s results. Evalution of the financial situation was done with the indexes of financial analysis. Events of this master´s work are specified solutions for improve market position and their possible implementation into the company.

Master's thesis describes analysis of the financial situation of company VIA-REK, Ltd. in years 2005 – 2008 through the chosen methods of financial analysis. It shows strong and weak sides, threads and opportunities of company VIA-REK, Ltd. And propose possible solutions, which could lead to improvement of the company financial situation.

The Diploma thesis are focused on evaluation of financial situation of company by methods of financial analyse. There will be analysed by system of ratios. The areas, where the system of ratios will presume problems, there will be focused analyse based on absolute, ratio and diference indexes. Along developed reality will be made scheme of solution.