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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Physical and numerical modelling investigation of induced bank erosion as a sediment transport restoration strategy for trained rivers : the case of the Old Rhine (France) / Rétablissement de la dynamique sédimentaire dans les cours d'eau aménagés par érosion induite des berges : modélisation physique et numérique, cas du Vieux-Rhin

Die Moran, Andrés 19 December 2012 (has links)
La dynamique sédimentaire des rivières, souvent modifiée par les aménagements, n'a pas été considérée comme un facteur significatif pour la qualité des environnements riverains et dans les stratégies de restauration. Les approches destinées à restaurer la charge sédimentaire d'une rivière afin qu'elle soit compatible avec les besoins environnementaux et humains, en termes de quantité de sédiments et de granulométrie, sont encore peu développées. De plus, les approches existantes telles que l'injection de sédiments sont souvent coûteuses et nécessitent une intervention humaine. Cette thèse porte sur l'érosion induite des berges, qui constitue une alternative plus durable pour l'environnement. Cette approche consiste à accroître le potentiel d'érosion en certains sites le long des berges d'une rivière chenalisée, en leur permettant d'être plus fortement érodés lors de crues. Deux approches, un modèle physique et des simulations numériques, ont été utilisées pour étudier un site localisé sur le Vieux-Rhin, en aval de Bâle (Suisse), où une modification des épis éxistents est prévue afin de favoriser l'érosion des berges. Dans un premier temps, différents scénarios de modification ont été testés sur une gamme de débits, au moyen d'un modèle physique à échelle de Froude non distordue avec un lit mobile. Dans ce modèle physique, un mélange de quatre classes granulométriques a été adopté afin de reproduire la courbe granulométrique mesurée en nature. Le modèle a été mis à l'échelle par une méthode spécifique qui représente avec précision le début du mouvement de chaque classe. Une stratégie efficace d'érosion des berges a été établie, qui libère des sédiments sans provoquer un retrait excessif des berges qui puisse compromettre la sécurité d'un chenal de navigation adjacent. Par la suite, l'aptitude du modèle numérique Telemac2D à modéliser l'érosion et les processus de rupture de berge a été évaluée. L'algorithme existant de rupture de berge a été modifié pour améliorer les résultats, et les développements implémentés ont été validés par des comparaisons sur des cas-tests de laboratoire. Enfin, les essais du modèle physique ont été simulés numériquement à la même échelle. Les simulations reproduisent les processus observés sur le modèle physique, et les volumes de sédiments érodés et déposés sont du même ordre de grandeur que ceux mesurés / Sediment transport dynamics, often heavily modified by river training, are not yet sufficiently considered as a significant factor in riparian environmental quality and river restoration strategies. Approaches for restoring a river's sediment in quantity and in grain size distribution, so that it is compatible with both ecological and human needs, are still under development. Furthermore, existing approaches such as direct sediment injection are often expensive and require human intervention. This thesis explores induced bank erosion, a more environmentally sustainable alternative. This approach involves increasing the potential for erosion at certain sites along the bank of a trained river, and allowing them to be eroded during high flow periods. Two modelling approaches, physical scaled models and numerical simulation, were used to study a site located on the Old Rhine downstream of Basle (Switzerland) where existing bank protection groynes will be modified to induce bank erosion. Firstly, different modification options were tested over a range of flow rates with a Froude-scaled undistorted movable-bed physical model. The physical model used a mixture of four grain sizes to reproduce the bank grain size distribution found at the site, and was scaled according to a specific method which accurately represents initiation of motion for each grain size. An effective bank erosion strategy was found that releases sediment without compromising the safety of an adjacent navigation channel through excessive bank retreat. Subsequently, the capability of the Telemac2D two-dimensional depth-averaged numerical modelling system to model bank erosion and failure processes was assessed, and the existing bank failure algorithm was modified in order to improve results. Algorithm developments were tested with two laboratory test cases. Then, the physical model tests were simulated at their same scale. Simulations reproduced the processes present in the physical model tests, and volumes of eroded and deposited sediment were of the same order of magnitude
62

Perspectiva histórica e tecnológica da calibração do túnel 2 do Sistema Cantareira de adução de água para a região metropolitana de São Paulo / Historical and technological perspective of the test for the calibration of tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo

Pinheiro, Hemerson Donizete 22 March 2007 (has links)
Trabalhos de cunho historiográfco que visam resgatar a produção científica e tecnológica de um país tem auxiliado a compreender e a classificar seu nível de desenvolvimento frente a estas questões. Com este trabalho, espera-se dar início no Departamento de Hidráulica e Saneamento (SHS) da Escola de Engenharia de São Carlos, a um levantamento historiográfico da produção tecnológica e científica de seus pós-graduandos e professores. Para tanto, resgata-se um trabalho realizado entre o final da década de 1960 e início da década de 1970, pela Cátedra de Mecânica dos Fluidos (precursora do SHS), que teve como objetivo prever a vazão de água do túnel 2 do Sistema Cantareira de abastecimento de água para a região metropolitana de São Paulo. Nesta galeria foi realizado um ensaio original com circulação de ar, para o qual foram desenvolvidos métodos e técnicas a fim de verificar a vazão e auxiliar no seu dimensionamento, para garantir uma adução de 33 \'M POT.3\'/s. Mediante o levantamento, organização cronológica e análise dos documentos produzidos pelos autores do referido ensaio, resgatam-se as influências teóricas que nortearam as metodologias, as técnicas e tecnologias e analisam-se, de acordo com os registros documentais, a execução e resultados alcançados pelos ensaios. / Works that have as objective to review the scientific and technological production of a country have helped to understand and to measure its level of development regarding these questions. With this work, hopefully a historical survey of the technological and scientific production of its graduate students and teachers begins at the Departamento de Hidráulica e Saneamento (SHS) at the Escola de Engenharia de São Carlos. In this way, a work that was carried out between the end of the 1960\'s and beginning of the 1970\'s, by the chair of fluid mechanics (precursor of the SHS), which had as objective to foresee the water flow rate at tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo. An original test using air circulation was carried out in the tunnel. Methods and techniques were developed in order to verify the flow rate and check its size, to guarantee 33 \'M POT.3\'/s of flow. The documents produced by the authors of the test were surveyed, organized chronologically and analyzed, seeking to infer the theoretical influences that had guided the methodologies, to describe the techniques and technologies and to analyze, in accordance with the document registers, the execution and results reached from the tests.
63

Customização em massa de projeto de habitação de interesse social por meio de modelos físicos paramétricos / Mass customization of social housing project through parametric physical models

Mauricio Hidemi Azuma 08 March 2016 (has links)
Esta pesquisa aborda como problema principal, a falta de participação do usuário de Habitação de Interesse Social (HIS) na definição da sua moradia. O modelo atual do processo de provisão da habitação é baseado, principalmente, no sistema de produção em massa, resultando em unidades habitacionais padronizadas que não atendem às necessidades de seus usuários. Dentro deste cenário, a Customização em Massa (CM), tem sido investigada e apontada como uma estratégia promissora para solucionar este problema. A CM é definida como uma síntese de dois sistemas, aparentemente concorrentes: o da produção em massa com a customização individual de bens ou serviços. A participação do cliente na configuração do seu produto é uma condição essencial no conceito da CM, para o atendimento de suas necessidades e desejos. Para viabilizar essa participação, é necessária a utilização de ferramentas que permitam aos clientes configurarem seus produtos, a partir de opções disponibilizadas pelo fabricante. Especificamente no setor da construção civil, estas ferramentas ainda precisam ser desenvolvidas e experimentadas. Neste contexto, o objetivo principal da pesquisa é desenvolver um instrumento funcional que apoie os usuários, nas decisões da customização da sua habitação, em processos participativos de projetos de HIS. A pesquisa utiliza a abordagem da Design Science Research, a qual orienta para que, após a compreensão da questão central, seja proposto um artefato aplicável em soluções práticas. Os resultados obtidos com a aplicação do artefato desenvolvido demonstraram que o mesmo pode ser utilizado, não apenas na CM, mas também em outros processos de projetos participativos. A principal contribuição desta pesquisa está na originalidade das características paramétricas do modelo físico proposto. / This research approaches, as a main problem, the lack of user participation in Social Housing regarding the definition of its dwelling. The current model of housing provision process is based, mainly, on the mass production system, resulting in standardized housing units that do not satisfy the needs of users. Within this background, the Mass Customization (MC), has been investigated and identified as a promising strategy to solve this problem. The MC is defined as a synthesis of two systems, seemingly competitive: the mass production with the individual customization of goods or services. The customer participation in his product configuration is an essential condition in the concept of MC to fulfill his needs and desires. In order to enable this participation, the use of tools is required to enable customers to configure their products, from options, provided by the manufacturer. Specifically, in the civil construction sector these tools still need to be developed and experienced. In this context, the main objective of this research is the development of a functional device that can support users in their decisions of housing customization in participatory processes of Social Housing projects. The research uses the Design Science Research approach, which after understanding the central issue, recommends the development of an artifact and its application in practical solutions. The results obtained by applying the developed artifact demonstrated that the latter can be used, not only in MC, but also in other participatory design processes. The main contribution of this research is the originality of the parametric features of the proposed physical model.
64

Customização em massa de projeto de habitação de interesse social por meio de modelos físicos paramétricos / Mass customization of social housing project through parametric physical models

Azuma, Mauricio Hidemi 08 March 2016 (has links)
Esta pesquisa aborda como problema principal, a falta de participação do usuário de Habitação de Interesse Social (HIS) na definição da sua moradia. O modelo atual do processo de provisão da habitação é baseado, principalmente, no sistema de produção em massa, resultando em unidades habitacionais padronizadas que não atendem às necessidades de seus usuários. Dentro deste cenário, a Customização em Massa (CM), tem sido investigada e apontada como uma estratégia promissora para solucionar este problema. A CM é definida como uma síntese de dois sistemas, aparentemente concorrentes: o da produção em massa com a customização individual de bens ou serviços. A participação do cliente na configuração do seu produto é uma condição essencial no conceito da CM, para o atendimento de suas necessidades e desejos. Para viabilizar essa participação, é necessária a utilização de ferramentas que permitam aos clientes configurarem seus produtos, a partir de opções disponibilizadas pelo fabricante. Especificamente no setor da construção civil, estas ferramentas ainda precisam ser desenvolvidas e experimentadas. Neste contexto, o objetivo principal da pesquisa é desenvolver um instrumento funcional que apoie os usuários, nas decisões da customização da sua habitação, em processos participativos de projetos de HIS. A pesquisa utiliza a abordagem da Design Science Research, a qual orienta para que, após a compreensão da questão central, seja proposto um artefato aplicável em soluções práticas. Os resultados obtidos com a aplicação do artefato desenvolvido demonstraram que o mesmo pode ser utilizado, não apenas na CM, mas também em outros processos de projetos participativos. A principal contribuição desta pesquisa está na originalidade das características paramétricas do modelo físico proposto. / This research approaches, as a main problem, the lack of user participation in Social Housing regarding the definition of its dwelling. The current model of housing provision process is based, mainly, on the mass production system, resulting in standardized housing units that do not satisfy the needs of users. Within this background, the Mass Customization (MC), has been investigated and identified as a promising strategy to solve this problem. The MC is defined as a synthesis of two systems, seemingly competitive: the mass production with the individual customization of goods or services. The customer participation in his product configuration is an essential condition in the concept of MC to fulfill his needs and desires. In order to enable this participation, the use of tools is required to enable customers to configure their products, from options, provided by the manufacturer. Specifically, in the civil construction sector these tools still need to be developed and experienced. In this context, the main objective of this research is the development of a functional device that can support users in their decisions of housing customization in participatory processes of Social Housing projects. The research uses the Design Science Research approach, which after understanding the central issue, recommends the development of an artifact and its application in practical solutions. The results obtained by applying the developed artifact demonstrated that the latter can be used, not only in MC, but also in other participatory design processes. The main contribution of this research is the originality of the parametric features of the proposed physical model.
65

Propriétés mécaniques des verres métalliques massifs : Influence de la microstructure / Mechanical properties of bulk metallic glasses : Influence of microstructure

Qiao, Jichao 31 January 2013 (has links)
Ce travail a porté sur l’étude des propriétés thermiques et mécaniques des verres métalliques massifs. Dans le premier chapitre nous avons rappelé l’historique des verres métalliques massifs, leurs propriétés intéressantes et quelques applications de ces matériaux et nous les avons situés par rapport aux autres matériaux amorphes, tels que les polymères ou les verres d’oxydes. Nous avons analysé par différentes méthodes expérimentales (calorimétrie, analyse mécanique dynamique, diffraction des rayons X, microscopies électroniques) les caractéristiques de cette évolution et leur incidence sur les propriétés mécaniques. Différents alliages base zirconium, cuivre, titane ou lanthane ont été étudiés. Nous avons notamment montré que : ● Un chauffage à une température inférieure à la température de transition vitreuse (Tg) conduit à une relaxation structurale, dont la cinétique, étudiée par calorimétrie, peut être modélisée par une fonction de type exponentielle étendue. Les paramètres caractéristiques ont été déterminés pour les différents alliages étudiés. Cette relaxation conduit à une augmentation du module élastique de stockage, mais à une diminution de la composante viscoélastique de ce module, autrement dit à une diminution de la mobilité atomique. Une déformation plastique conduit à un effet inverse. Ces évolutions ont été interprétées à l’aide d’un modèle reposant sur l’existence de défauts, dont la concentration diminue lors de la relaxation structurale, mais augmente lors de la déformation plastique. ● Lorsqu’une contrainte mécanique périodique de faible amplitude est appliquée, on observe des relaxations mécaniques. Quelle que soit la composition de l’alliage, une relaxation importante est toujours observée au voisinage de la transition vitreuse, comme dans tous les autres matériaux amorphes. En plus, dans certains verres métalliques massifs, (exemple les verres base Lanthane), une relaxation secondaire est détectée à basse température. Cette relaxation, de faible énergie d’activation, est attribuée à des mouvements locaux qui se produisent dans les zones faibles du matériau, zones résultant de l’existence d’hétérogénéités à une échelle nanoscopique. ● Lorsque qu’une contrainte de forte amplitude est appliquée (cas des essais de compression), on observe un comportement caractéristique de tous les matériaux amorphes : comportement essentiellement fragile à basse température et écoulement viscoplastique à haute température. Une courbe maitresse a pu être tracée pour la viscosité. La transition d’un régime newtonien à un régime non-newtonien apparait lorsque la vitesse de déformation augmente. Tous les résultats expérimentaux ont été discutés dans le cadre d’un modèle physique, basé sur l’existence de défauts activés par une augmentation de température ou par une contrainte. / In the current work, we investigated the thermal and mechanical properties of bulk metallic glasses. The history of the bulk metallic glasses was described in the Chapter I. The clear interesting properties and applications of the bulk metallic glasses, compared with other amorphous materials, i.e. polymers and glassy oxides, were discussed. Different experimental methods [DSC, DMA, X-ray diffraction, electron microscopy] were used to investigate the features of evolution of the microstructure on mechanical properties for bulk metallic glasses. The different bulk metallic glasses, i.e. Zr-, Cu-, Ti- and La-based, have been studied in the current research. In particular, the main results as follows: ● A heat treatment performed below the glass transition temperature Tg induces the structural relaxation. The kinetics of the enthalpy relaxation was studied by differential scanning calorimetry and can be well fitted by a stretched exponential relaxation function. The characteristic parameters can be determined in different bulk metallic glasses. The structural relaxation leads to an increase of the storage modulus, on the contrary to a decrease of the visco-elastic component of the modulus. Namely, the structural relaxation induces a diminution of the atomic mobility. The plastic deformation leads to an inverse influence. Results are interpreted using a physical model, based on the existence of defects in the material, called quasi-point defects. Atomic mobility is reduced by structural relaxation due to decrease of the concentration of defects. In contrast, plastic deformation increases the concentration of defects and therefore enhances the atomic mobility. ● When a periodic mechanical stress with a low amplitude is applied, one can observe mechanical relaxation. The main (α) relaxation has been clearly observed near to the glass transition temperature in all the investigated bulk metallic glasses as well as other amorphous materials. In addition, in some cases of bulk metallic glasses (for example, Lanthanum-based metallic glass), a distant secondary relaxation has been detected at lower temperature. This relaxation presents lower activation energy, which is associated to dynamic heterogeneities and is related to local movements of “defect” on the nature of nanoscale order in glasses. ● When a large-amplitude stress is employed (case of the compression tests), one can acquire the characteristic behaviour of the amorphous materials: A typical brittle fracture phenomenon is observed at lower temperature and the flow stress can be detected at higher temperature. A master curve of the viscosity can be acquired based on the experimental results. The transition from a Newtonian to non-Newtonian regime appears when the strain rate increases. All the experimental results are discussed in the framework of physical models, based on existence of the defects, which can be activated by increasing temperature or stress.
66

Theoretical and experimental study of the role of the reed in clarinet playing / Étude théorique et expérimentale du rôle de l’anche dans le jeu de la clarinette

Taillard, Pierre-André 02 July 2018 (has links)
Ce mémoire traite de l'acoustique de la clarinette et du rôle de l'anche, résumant des travaux menés entre 2001 et 2018 sur divers sujets :I) Étude de modèles analytiques élémentaire focalisée sur : 1) le rôle des pertes. 2) les cartes itérées, mettant en évidence divers régimes de fonctionnement, utiles aussi pour la pédagogie instrumentale. II) Étude de caractérisation des anches : 1) Étude dynamique des résonances de l'anche réalisée par holographie. Elle conduit à un modèle de matériau viscoélastique expliquant certaines différences observées dans les fréquences des 15 premiers modes de l'anche. 2) Étude statique des caractéristiques mécaniques et aérauliques de l'excitateur (anche+bec+lèvre). La méthode mesure précisément la quantité d'air entrant dans l'instrument en fonction de la pression de lèvre et d'air. III) Synthèse sonore par modèle physique en temps réel : 1) Modélisation mécanique et aéraulique de l'anche, d'après mesure. Le modèle de ressort raidissant non linéaire proposé autorise une simulation dynamique efficace. 2) Estimation modale de l'impédance d'entrée (mesurée) des instruments à vent. On montre les techniques de conception de filtres numériques précis et passifs à toute fréquence. 3) Modélisation et simulation instruments à vent au moyen de guide-ondes, par estimation modale, implémentée dans un logiciel en C++. IV) Une étude de jouabilité d'un panel de 40 anches par analyse canonique des corrélations révèle des liens statistiquement solides entre mesures physiques, évaluations subjectives et synthèse sonore. Elle autorise une caractérisation des anches pouvant être réalisé par le fabricant, selon au moins 4 facteurs indépendants. / This thesis deals with the acoustics of the clarinet and the role of the reed, summarizing studies carried out between 2001 and 2018 on various topics : I) Study of elementary analytical models, focused on 1) role of losses. 2) iterated maps, highlighting various operating regimes, which are also useful for the instrumental pedagogy. II) Reed characterization study : 1) Dynamic study of the reed resonances, by holography. It leads to a model of viscoelastic material explaining some differences observed in the frequencies of the first 15 modes of the reed. 2) Static study of the mechanical and aeraulic characteristics of the exciter (reed + mouthpiece + lip). The method accurately measures the airflow entering the instrument as a function of lip and air pressure. III) Sound synthesis by physical model in real time : 1) Mechanical and aeraulic modeling of the reed, according to measurements. The proposed nonlinear stiffening spring model allows for an efficient dynamic simulation. 2) Modal estimation of the (measured) input impedance of wind instruments. Design techniques for accurate digital filters, passive at any frequency, are described. 3) Modal estimation and simulation of wind instruments by waveguides, implemented in C ++ software. IV) A playability study of a panel of 40 reeds by canonical correlation analysis reveals statistically strong links between physical measurements, subjective evaluations and sound synthesis. It allows a characterization of the reeds that can be made by the manufacturer, according to at least 4 independent factors.
67

[en] DEVELOPMENT OF A PHYSICAL MODEL FOR THE ANALYSIS OF THUNDER EFFECTS IN SOILS / [pt] DESENVOLVIMENTO DE UM MODELO FÍSICO PARA A ANÁLISE DE EFEITOS DE TROVÕES EM SOLOS

THIAGO DE SOUZA CARNAVALE 21 November 2018 (has links)
[pt] O trabalho foi motivado pela grande incidência de descargas atmosféricas no desastre ocorrido na Região Serrana do Estado do Rio de Janeiro, em 2011. No episódio foram contabilizados mais de 900 óbitos e até o presente momento, as causas dos escorregamentos ainda não foram completamente encontradas. Esta pesquisa apresenta o desenvolvimento de um modelo físico para avaliar os efeitos das ondas sonoras, oriundas dos trovões, em solos. Para o alcance do referido objetivo, foi desenvolvida uma câmara à qual um bloco indeformado de solo foi instrumentado com tensiômetros, TDR s e acelerômetros. Os materiais utilizados nos ensaios são provenientes da encosta situada nos domínios da PUC-Rio e do condomínio localizado no bairro de Conquista - Nova Friburgo. Os solos foram dispostos em blocos livres ou confinados em uma caixa de compensado naval de 19 mm e a seguir os mesmo foram submetidos às ondas de sonoras replicadas da modelagem dos trovões. Os resultados abrangem o desenvolvimento de ensaios com umidades diferentes, para os dois tipos de materiais, nas condições livre e confinada, e foram satisfatórios. / [en] The work was motivated by the high incidence of lightning in the disaster occurred in the mountainous region of the State of Rio de Janeiro in 2011. In the episode was recorded more than 900 deaths and up to the present time, the causes of landslides have not been fully met. This research presents the development of a physical model to assess the effects of sound waves coming from the thunder in soils. To achieve the above goal, we developed a camera to which an undisturbed block of soil, instrumented with tensiometers and TDR s accelerometers was tested on a table. The materials used in the tests are from hillside located in the areas of PUC-Rio and condo located in the Conquista, Nova Friburgo. Soils were willing blocks free or confined in a box of 19mm plywood and then were subjected to the sound waves replicated modeling of thunder. The results include the development of assays with different humidities for both types of materials and conditions, free and confined.
68

Simulação de escoamentos não-periódicos utilizando as metodologias pseudo-espectral e da fronteira imersa acopladas / Simulation of non-periodics flows using the fourier pseudo-spectral and immersed boundary methods

Mariano, Felipe Pamplona 06 March 2007 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Modern engineering increasingly requires the comprehension of phenomena related to combustion, aeroacustics, turbulence transition, among others. For these purposes the Computational Fluids Dynamics (CFD) requires the used high order methods. One of these methods is the Fourier pseudo-spectral method, that provides an excellent numerical accuracy, and with the use of the Fast Fourier Transform algorithm (FFT), it presents a low computational cost in comparison to anothers high-order methods. Another important issue is the projection method of the pression term, which does not require the pressure computation from the Navier-Stokes equations. The procedure to calculate the pression field is usually the most onerous in classical methodologies. Nevertheless, the pseudo-spectral method can be only applied to periodic boundary flows, thus limiting its use. Aiming to solve this restriction, a new methodology is proposed at the present work, which has the objective of simulating nonperiodic flows using the Fourier pseudo-spectral method. For this purpose the immersed boundary method, that represents the boundary conditions through a force field imposed at Navier-Stokes equations is used. As a test to this new methodology, a classic problem of Computational Fluid Dynamics, The Lid Driven Cavity was simulated. The obtained results are promising and demonstrate the possibility to simulating non-periodic flows making use of the Fourier pseudo-spectral method. / Para compreender fenômenos relacionados à combustão, aeroacústica, transição a turbulência entre outros, a Dinâmica de Fluídos Computacional (CFD) utiliza os métodos de alta ordem. Um dos mais conhecidos é o método pseudo-espectral de Fourier, o qual alia: alta ordem de precisão na resolução das equações, com um baixo custo computacional. Este está ligado à utilização da FFT e do método da projeção do termo da pressão, o qual desvincula os cálculos da pressão da resolução das equações de Navier-Stokes. O procedimento de calcular o campo de pressão, normalmente é o mais oneroso nas metodologias convencionais. Apesar destas vantagens, o método pseudo-espectral de Fourier só pode ser utilizado para resolver problemas com condições de contorno periódicas, limitando o seu uso no campo da dinâmica de fluídos. Visando resolver essa restrição uma nova metodologia é proposta no presente trabalho, que tem como objetivo simular escoamentos não-periódicos utilizando o método pseudo-espectral de Fourier. Para isso, é utilizada a metodologia da Fronteira Imersa, a qual representa as condições de contorno de um escoamento através de um campo de força imposto nas equações de Navier-Stokes. Como teste, para essa nova metodologia, foi simulada uma cavidade com tampa deslizante (Lid Driven Cavity), problema clássico da mecânica de fluídos, que objetiva validar novas metodologias e códigos computacionais. Os resultados obtidos são promissores e demostram que é possível simular um escoamento não-periódico com o método pseudo-espectral de Fourier. / Mestre em Engenharia Mecânica
69

Perspectiva histórica e tecnológica da calibração do túnel 2 do Sistema Cantareira de adução de água para a região metropolitana de São Paulo / Historical and technological perspective of the test for the calibration of tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo

Hemerson Donizete Pinheiro 22 March 2007 (has links)
Trabalhos de cunho historiográfco que visam resgatar a produção científica e tecnológica de um país tem auxiliado a compreender e a classificar seu nível de desenvolvimento frente a estas questões. Com este trabalho, espera-se dar início no Departamento de Hidráulica e Saneamento (SHS) da Escola de Engenharia de São Carlos, a um levantamento historiográfico da produção tecnológica e científica de seus pós-graduandos e professores. Para tanto, resgata-se um trabalho realizado entre o final da década de 1960 e início da década de 1970, pela Cátedra de Mecânica dos Fluidos (precursora do SHS), que teve como objetivo prever a vazão de água do túnel 2 do Sistema Cantareira de abastecimento de água para a região metropolitana de São Paulo. Nesta galeria foi realizado um ensaio original com circulação de ar, para o qual foram desenvolvidos métodos e técnicas a fim de verificar a vazão e auxiliar no seu dimensionamento, para garantir uma adução de 33 \'M POT.3\'/s. Mediante o levantamento, organização cronológica e análise dos documentos produzidos pelos autores do referido ensaio, resgatam-se as influências teóricas que nortearam as metodologias, as técnicas e tecnologias e analisam-se, de acordo com os registros documentais, a execução e resultados alcançados pelos ensaios. / Works that have as objective to review the scientific and technological production of a country have helped to understand and to measure its level of development regarding these questions. With this work, hopefully a historical survey of the technological and scientific production of its graduate students and teachers begins at the Departamento de Hidráulica e Saneamento (SHS) at the Escola de Engenharia de São Carlos. In this way, a work that was carried out between the end of the 1960\'s and beginning of the 1970\'s, by the chair of fluid mechanics (precursor of the SHS), which had as objective to foresee the water flow rate at tunnel 2 of the Cantareira water project for the metropolitan area of São Paulo. An original test using air circulation was carried out in the tunnel. Methods and techniques were developed in order to verify the flow rate and check its size, to guarantee 33 \'M POT.3\'/s of flow. The documents produced by the authors of the test were surveyed, organized chronologically and analyzed, seeking to infer the theoretical influences that had guided the methodologies, to describe the techniques and technologies and to analyze, in accordance with the document registers, the execution and results reached from the tests.
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Évaluation et réduction des conséquences des mouvements de terrains sur le bâti : approches expérimentale et numérique / Evaluation and reduction of ground movements consequences on building : experimental and numerical approaches

Hor, Boramy 24 January 2012 (has links)
L’instabilité des cavités souterraines (mines, carrières, tunnels,…) peut induire les mouvements de terrains d’amplitude suffisante pour endommager les bâtiments et les infrastructures en surface. Les méthodes traditionnelles, utilisées dans les pratiques d’ingénieur pour prévoir les déformations dans les structures, sont basées sur les caractéristiques des mouvements de terrain en condition de terrain vierge sans prendre en compte l’effet de la présence des structures en surface. L’objectif de cette thèse est de prédire les déformations des ouvrages en tenant compte de l’influence de l’interaction sol-structure, d’une part ; et d’évaluer la performance d’une solution de protection (tranchée périphérique), d’autre part. Cela a été achevé par la réalisation d’études paramétriques utilisant deux approches complémentaires : une approche expérimentale à l’aide d’un modèle réduit physique 3D sous gravité normale et une modélisation numérique 3D par la méthode des éléments finis. En particulier l’effet d’un certain nombre de paramètres géométriques et mécaniques a pu être investigué dans l’étude de l’interaction sol-structure : la position de la structure par rapport à la cuvette d’affaissement, le poids de la structure et la raideur relative entre le sol et la structure. Concernant l’étude de l’efficacité de tranchées périphériques, l’effet de la position de la structure, de la position de la tranchée vis-à-vis de la structure et de la rigidité de la tranchée a été analysé. Les résultats obtenus ont abouti à une meilleure compréhension du problème d’interaction sol-structure et ont montré l’importance de cet effet qui doit être pris en compte dans l’évaluation de la vulnérabilité du bâti. Le transfert des mouvements du sol à la structure est faible (moins de 2,5%), dans le cas modélisé : structure rigide et interface glissante. Les différents résultats ont permis par ailleurs de mettre en évidence l’efficacité de la tranchée périphérique pour réduire les sollicitations affectant les structures. La tranchée doit être remplie avec un matériau très déformable et surtout placée à une distance de l’ordre d’un mètre de la structure. / The instability of underground cavities due to mining or tunneling activities can induce surface ground movements which damage overlying buildings and infrastructures. The conventional design methods, used in engineering practices to assess the structure’s deformations, are based on greendfield ground movements without taking into account the effect of the surface structure. The objective of this thesis is to predict the building deformations by taking the in-fluence of the soil-structure interaction into consideration, and to evaluate the performance of a mitigation technique (peripheral trench). This has been achieved by performing parametric studies using both the experimental approach by means of a 3D small-scale physical model under earth gravity condition and the 3D finite element numerical modeling. In particular the effect of building position, building weight, and relative stiffness of building and underlying soil has been investigated in the soil-structure interaction study. Concerning the trench effectiveness analysis, the effect of building position, trench position relatively to the building, and the trench stiffness has been investigated. The results of these investigations have led to a better understanding of the soil-structure interaction problem and have pointed out the importance of this effect which should be taken into account for building damage assessment. The transfer of ground movements to the buildings is low (less than 2.5%) for the modeled case: stiff structure and sliding contact. In addition, the results have proved the effectiveness of the peripheral trench to reduce the ground movements affecting the buildings. The trench should be filled with a very deformable material and located at a distance of around one meter from the building.

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