Submitted by GUILHERME HENRIQUE FIOROT null (ghfiorot@aluno.feis.unesp.br) on 2016-08-31T16:48:18Z No. of bitstreams: 1 GHFiorot-tese-unesp.pdf: 21279930 bytes, checksum: f08d052fded3d144bcad4b9a9f1c007f (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-09-01T17:08:21Z (GMT) No. of bitstreams: 1 fiorot_gh_dr_ilha.pdf: 21279930 bytes, checksum: f08d052fded3d144bcad4b9a9f1c007f (MD5) / Made available in DSpace on 2016-09-01T17:08:21Z (GMT). No. of bitstreams: 1 fiorot_gh_dr_ilha.pdf: 21279930 bytes, checksum: f08d052fded3d144bcad4b9a9f1c007f (MD5) Previous issue date: 2016-07-01 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Dentro da temática de riscos naturais, mais precisamente no contexto das corridas de lama, esta tese surge da necessidade que existe na literatura em melhor se conhecer as características temporais destes eventos. A chuva, fonte da vazão liquida, conduz aos escoamentos superficiais, responsáveis pela redução da coesão do material sedimentar do solo (areia e argila) e seu consequente transporte. Em locais de topografia íngreme, de montante a jusante, a vazão sólida do escoamento principal pode, eventualmente, evoluir devido às contribuições laterais de pequenos escoamentos, alterando não só as propriedades reológicas do fluido e dinâmicas do escoamento, como se manter até que o transporte sólido atinja elevada concentração na composição do fluido. Na primeira parte desta tese, um experimento de superfície livre foi projetado para reproduzir escoamentos superficiais sobre um fundo móvel, com o objetivo de estudar propriedades não-permanentes do transporte de sedimentos. Um sistema de medição foi projetado e construído com o intuito de medir quase instantaneamente a vazão sólida e suas correlações com as propriedades hidráulicas do escoamento. Este aparato é também utilizado para observar a influência de instabilidades de superfície livre sobre o transporte. Um conjunto de resultados é apresentado e analisado e mostra que a presença de ondas pode, em média, reduzir a quantidade total de sedimentos transportada. Na segunda parte desta tese, a dinâmica de escoamentos com elevada concentração de sedimentos é estudada. Neste trabalho, executa-se a aplicação de um modelo de primeira ordem de roll waves para fluidos de reologia Herschel-Bulkley para simular um evento natural registrado na literatura. Os resultados apresentados mostram que roll waves poderiam, de fato, ser identificadas no evento e que a amplitude média observada poderia ter sido estimada com 8% de incerteza. Assim, um modelo mais complexo para a solução do perfil de velocidade é proposto, adicionando a porosidade do solo ao problema. Resultados do modelo são comparados com simulações numéricas. Uma análise paramétrica é efetuada e o caso de estudo é novamente avaliado. Como conclusão geral do trabalho, a presença de fenômenos não-estacionários durante a evolução escoamento superficial - corrida de lama afeta a dinâmica global do sistema acoplado hidráulica-transporte de sedimentos, quando comparado ao caso permanente e uniforme. Assim, a verificação de que tais fenômenos podem aparecer deve constituir parte de projetos engenharia, especialmente quando estes, em situações de catástrofes, envolvem danos a infraestruturas civis e quase sempre perdas de vidas, como é o caso das corridas de lama. / This thesis was motivated by the need to better understand time-dependent features related to mudflow evolution on natural sloped channels. Basically, the research is focused on events that are confined in channels formed due to the topography. The rain, source of the liquid discharge, generates the runoff flow which is responsible for wetting the soil surface, promoting reduction of soil cohesiveness and erosion of small particles such as clay and sand. From this point, the sediment transport can increase as small water flows merge and form greater streams. The scenario keeps its evolution until it reaches high concentration of particles in the fluid mixture. In the first part, to study the non-permanent feature of sediment transport, an open-channel experiment was designed for simulating runoff flow over a mobile bed. A measurement system was designed and constructed to instantaneously inspect the solid discharge of particles and the flow friction at the bed. This apparatus is further used to explore the influence of free-surface waves on the sediment transport. Hydraulic properties of flows are qualitatively and quantitatively studied and data are used to correlate characteristics of flow and sediment transport. A set of experimental runs is presented and explored. Analysis of results shows that for fixed flow conditions, waves induce an overall smaller quantity of transported sediment. In a second part, the dynamics of high concentrated flows is addressed and this thesis attempts to apply a first-order roll-wave model for Herschel-Bulkley laminar fluid flow to a registered natural event. Results presented point out that roll waves could have occurred during this already published case-study event. Simulations could predict wave heights within 8% on uncertainty with respect to the mean amplitude of measured waves. Finally a new theoretical solution for the velocity profile is proposed taking into account the porosity of the bed. Results are then compared with numerical simulation performed in FLUENT. A parametric analysis is employed and the case-study is once again evaluated. As general conclusion, the non-permanent phenomena that can appear during the evolution of a mudflow event affect the overall dynamics of the coupled system (hydraulic-sediment transport) in comparison to the steady and uniform case. Verifying that such phenomena could appear should indeed be an important part in hydraulic engineering projects, especially when dealing with lives, which is the case of mudflows. / CNPq: 201557/2012-6

A drenagem ácida de mina (DAM) gerada no processo de mineração de carvão, na presença de minerais sulfetados, tem provocado danos ambientais significativos no ecossistema de sua abrangência. Tecnologia de tratamento ativo baseada em processos de Neutralização, Precipitação e Sedimentação tem sido empregada para atenuar a carga de poluentes no efluente, antes do seu descarte em corpos receptores. A mesma, apesar da sua eficiência vem se mostrando bastante onerosa quando aplicada durante um longo período, devido aos custos com insumos, manutenção, potencial humano e energia. Nos últimos anos, vem sendo desenvolvidos sistemas que socorrem-se da ocorrência natural de processos químicos, biológicos e físicos para purificar água de mina contaminada. Estes são designados sistemas passivos, cuja implantação e funcionamento tem se mostrado menos onerosa em relação ao sistema ativo. Capão da Roça, situado no município de Charqueadas é uma das regiões do Brasil onde ocorre contaminação de solos e rios pela DAM gerada a partir de um depósito de rejeitos. Aplicando o fluxograma recomendado por diversos autores para a seleção do sistema passivo, tomando em conta as características do efluente achou-se viável instalar um canal aberto de calcário para o tratamento da DAM do Capão da Roça em virtude de a mesma apresentar acidez maior que a alcalinidade, oxigênio dissolvido maior que 5mg/l, Fe+3 maior que 25% em relação ao Fe2+. A quantidade de efluente e a declividade do terreno da área estudada permite que se opere com vazão maior que 12m3/h no sistema passivo. De acordo com a acidez do efluente foi determinado o tempo de detenção de 1hora para o tratamento da DAM no sistema. A partir de estudos similares sobre o uso de calcário em sistemas passivos, encontrou-se a massa de 338,6 toneladas para o empreendimento funcionar em 10 anos, considerando uma dissolução de calcário de 100%, num canal com 10% de declividade, 1m de profundidade e 2, 5 metros de largura para tamponar uma solução de DAM com vazão de 1000 L.min-1 num canal de 47metros de cumprimento. De acordo com cálculos baseados num modelo empírico, ficou demonstrado que o diâmetro e área de superfície do calcário poderão diminuir ao longo do tempo, considerado a sua dissolução. / Acid mine drainage (AMD) generated in the coal mining process in the presence of sulfide minerals, have been causing significant environmental damages to the ecosystem of its coverage. Active treatment technology based on neutralization, precipitation and sedimentation processes, has been used to alleviate the load of pollutants in the effluent prior to discharges into receiving bodies. Despite their efficiency has proved quite costly when applied over a long period due to input costs, maintenance, manpower and energy. In recent years project defined 'passive treatment' has been developed as the improvement of water quality using only naturally occurring chemical, biological and physical processes, hence, the deployment and operation have been less costly compared to the active systems. Capão da Roça, located in the municipality of Charqueadas is one of the regions of Brazil where occurs contamination of soils and rivers by AMD generated from a waste dump. Using the flowchart recommended by several authors for selecting the passive system, taking into account the wastewater characteristics, was found to be feasible to install an open limestone channel for the treatment of AMD because it has higher acidity than alkalinity, dissolved oxygen greater than 5mg / l, Fe3+ greater than 25 % in relation to Fe2+. The amount of effluent and the slope of the study area terrain allows to operate with a flow rate greater than 12m3/ h in the passive system. According to the acidity of the effluent was determined retention time of 1 hour for the treatment of the AMD system. From similar studies on the use of limestone in passive systems, was found the mass of 338.6 tons for the enterprise operating over 10 years, assuming a 100% limestone dissolution channel with a 10% slope, 1 meter deep and 2,5 meters wide to buffer an AMD solution with a flow rate of 1000 L.min-1 in channel with 47 meters of length. According to the calculations based on empirical model, it was shown that the diameter and the surface area of limestone may decline over time, considering its dissolution.

La plupart des réseaux d'irrigation gravitaire traditionnels, encore majoritaires dans le monde, distribuent l'eau aux parcelles agricoles à travers un réseau de canaux à surface libre. La distribution de l'eau sur ce type de réseau suit en général le mode de distribution au tour d'eau (tour d'eau fixe, modulé, arrangé ou mixte) et nécessite de définir un planning de manœuvre des vannes et un calendrier d'arrosage. La performance de la distribution d'eau est généralement très faible, du fait de contraintes de l'infrastructure, de main d'œuvre et d'évolutions des demandes en eau.La thèse propose une méthode générique permettant d'optimiser les manœuvres des vannes et le calendrier d'arrosage, ainsi que des stratégies de modernisation basées sur la mise en place de vannes automatiques et réservoirs tampon.La méthode est basée sur la programmation linéaire en variables mixtes (MILP). La définition des contraintes et des objectifs s'appuie sur l'analyse de deux périmètres traditionnels du Sud de la France, ainsi que sur une description des principales caractéristiques hydrauliques des systèmes de transport d'eau. Les méthodes prennent en compte trois critères d'optimisation : l'adéquation, la main d'œuvre et l'efficience hydraulique, ces critères pouvant être pondérés pour tenir compte de priorités.La méthode développée est testée sur un réseau virtuel, puis appliquée à un système réel où les évolutions récentes ont profondément dégradé l'adéquation offre-demande. La méthode permet alors de réduire fortement les volumes d'eau prélevés en tête de réseau mais non utilisés par les usagers, tout en assurant une très bonne adéquation offre-demande.L'enjeu de la modernisation des réseaux traditionnels est abordé sur un réseau au tour d'eau fixe, fortement contraint par la charge de travail pour manœuvrer les ouvrages. On montre, sur un site réel, comment définir des priorités de mise en place de vannes automatiques. Dans d'autres cas, la modernisation peut se faire par la mise en place de réservoirs tampon dont l'emplacement et le volume peuvent être optimisés. / Most traditional gravity irrigation networks, still the majority in the world, deliver water to farm field (offtakes) through an open channel network. Water distribution on this type of network is generally based on irrigation schedule/delivery methods (fixed rotation, central system, arranged or mixed schedule) and requires two schedules: one for irrigation and another for gate operations. Water distribution performance of this system is low due to hydraulics infrastructures constraints, manpower and water demand evolution.The thesis proposes a generic method for optimizing gate operations and irrigation schedules, as well as modernization strategies based on the development of automated gates and buffer reservoirs.The method uses mixed integer linear programming (MILP). The definition of constraints and objectives is based on the analysis of two traditional irrigation networks of Southern France, as well as a description of the main characteristics of hydraulic systems for water delivery. Methods take into account three optimization criteria: adequacy, hydraulic efficiency and manpower. These criteria can be weighted for setting the priorities.The developed method is tested on a virtual network, and then applied to a real system where recent evolution have profoundly damaged the adequacy between supply and demand. We show that the method can greatly reduce the volume of water withdrawn by the network, and not used by users, for ensuring a good adequacy between supply and demand.The challenge of modernization is taken into account for an open channel network which is strongly constrained by manpower for gates operations. It is shown on a real network, how to set priorities for implementation of automatic gates. In other cases, the modernization may be achieved by the implementation of the buffer reservoir which location and volume can be optimized.

Orientador: Geraldo de Freitas Maciel / Abstract: This thesis was motivated by the need to better understand time-dependent features related to mudflow evolution on natural sloped channels. Basically, the research is focused on events that are confined in channels formed due to the topography. The rain, source of the liquid discharge, generates the runoff flow which is responsible for wetting the soil surface, promoting reduction of soil cohesiveness and erosion of small particles such as clay and sand. From this point, the sediment transport can increase as small water flows merge and form greater streams. The scenario keeps its evolution until it reaches high concentration of particles in the fluid mixture. In the first part, to study the non-permanent feature of sediment transport, an open-channel experiment was designed for simulating runoff flow over a mobile bed. A measurement system was designed and constructed to instantaneously inspect the solid discharge of particles and the flow friction at the bed. This apparatus is further used to explore the influence of free-surface waves on the sediment transport. Hydraulic properties of flows are qualitatively and quantitatively studied and data are used to correlate characteristics of flow and sediment transport. A set of experimental runs is presented and explored. Analysis of results shows that for fixed flow conditions, waves induce an overall smaller quantity of transported sediment. In a second part, the dynamics of high concentrated flows is addressed and this the... (Complete abstract click electronic access below) / Resumo: Dentro da temática de riscos naturais, mais precisamente no contexto das corridas de lama, esta tese surge da necessidade que existe na literatura em melhor se conhecer as características temporais destes eventos. A chuva, fonte da vazão liquida, conduz aos escoamentos superficiais, responsáveis pela redução da coesão do material sedimentar do solo (areia e argila) e seu consequente transporte. Em locais de topografia íngreme, de montante a jusante, a vazão sólida do escoamento principal pode, eventualmente, evoluir devido às contribuições laterais de pequenos escoamentos, alterando não só as propriedades reológicas do fluido e dinâmicas do escoamento, como se manter até que o transporte sólido atinja elevada concentração na composição do fluido. Na primeira parte desta tese, um experimento de superfície livre foi projetado para reproduzir escoamentos superficiais sobre um fundo móvel, com o objetivo de estudar propriedades não-permanentes do transporte de sedimentos. Um sistema de medição foi projetado e construído com o intuito de medir quase instantaneamente a vazão sólida e suas correlações com as propriedades hidráulicas do escoamento. Este aparato é também utilizado para observar a influência de instabilidades de superfície livre sobre o transporte. Um conjunto de resultados é apresentado e analisado e mostra que a presença de ondas pode, em média, reduzir a quantidade total de sedimentos transportada. Na segunda parte desta tese, a dinâmica de escoamentos com eleva... (Resumo completo, clicar acesso eletrônico abaixo) / Doutor

Recently it has become more common in the construction of large dams to reuse diversion tunnels as flood discharge tunnels in the final structure. These tunnels handle large flows with the characteristics of open channel flow. When such large hydrological forces act upon a structure there are several problems to be expected. One of these is the occurrence of cavitation, which could have potential hazardous erosion as a consequence. Cavitation is the formation and collapse of bubbles that create a shockwave strong enough to erode the underlying material. The Baihetan dam is one of the largest hydro power projects in China at present. It has three discharge tunnels that all run the risk of developing cavitation damages. By modelling one of the tunnels using Computational Fluid Dynamics (CFD) it is possible to investigate where in the tunnel structure cavitation is likely to occur. This degree project assesses the risk of cavitation erosion in the Baihetan tunnel using the static pressure distribution, the velocity distribution and modern cavitation theory. Several modifications of the tunnel – including alterations in the gradient and construction parameters – are simulated in order to investigate if changes in the design can mitigate the cavitation problem. None of the analysed modifications completely eliminate the problem and aeration is recommended to counteract the problem. This study indicates where cavitation might be a problem in the Baihetan tunnel and can be used as a basis for further research.

CFD is today a big part of the design process in hydraulic engineering and is more economical and time efficient than traditional scale models. But, there are still issues concerning the agreement with scale models in large and complex geometries. In this degree project a high head, five channeled, slotted flip bucket spillway system is analyzed with the CFD software FLUENT and compared with existing scale model results. The sought hydraulic parameters in each channel were the discharge capacity, the pressure distribution and the throw distance from the flip buckets. The discharge capacity and pressure distribution was practically equal for all five channels and only the throw distance from Channel 1 deviated from the others. The agreement with data from the scale model is quite low. The biggest error sources behind the bad agreement may depend on the lack of computational power which led to bad choice of cell size, model delimitations and simplifications. CFD models can easily be built up by people without experience in hydraulics which can lead to fatal errors when building up the model and interpreting results. Hence, long experience in CFD or verification of the numerical results with several different hydraulic parameters is the only way to guarantee qualitative results from CFD modeling.

The longitudinal solute transport modeling is critical in river and stream water quality management, control, and the mitigation of hazardous riverine spills. One of the widely used "deadzone" model is the transient storage model (TSM). TSM is a significant improvement over the advection-dispersion model (ADM), but it cannot simulate the breakthrough curve (BTC) immediately after a large pool. Additionally, the calibration (parameterization) method is challenged by the non-identifiability which is common to all inverse modeling, and it seems TSM cannot be easily used as a predictive tool, more of an interpretive tool of solute transport, i.e., is the parameter set calibrated via inverse modeling transferable? Pools are fundamental stream morphology unit in streams with mixed bed materials in pool-riffle or pool-step sequences. Understanding of how a pool impacts the longitudinal solute transport is the first step towards improving current model such as TSM or developing new models. By introducing a dimensionless group, e= Q/(Dt W) (where, Q is the average volumetric flow rate; Dt is an average transverse dispersion coefficient; W is the channel flow width), derived from non-dimensionalization of the governing equations of one of the most rigorous 2-dimansional (2D) (depth-averaged) model, Mike21, this work presents an alternative way of longitudinal solute transport investigation. Using the 2D fully hydrodynamic Mike21, numerical experiments were conducted on hypothetical streams in this dissertation. Simulation study on hypothetical stream with pool reveals that a pool's effects on longitudinal solute transport are manifested by three aspects: boosting longitudinal spreading (concentration peak attenuation), causing a solute plume delay and increasing solute residence time. These effects fade like a "wake" as the solute plume moves downstream. e provides an insight into the physics of longitudinal transport; it outlines a relative transverse mixing intensity of a stream. The internal transport and mixing condition (including the secondary circulations) in a pool together with the pool's dimensions determine the pool's storage effects especially when e >>1. The BTCs downstream from a pool may be "heavy tailed" (i.e., have enormously slow decaying rate) which cannot be modeled by the TSM. Results also suggest that the falling limb of a BTC more accurately characterizes the pool's storage effects because the corresponding solute has more chance to sample the entire storage area. n a more fundamental perspective, the predictive ability of inverse modeling parameterized model is discussed and conclusion is made about the role of a stream/river system's nonlinearity in determining the predictability; a misleading mis-nomenclature in TSM application is also demonstrated with a numerical experiment. / Civil Engineering

Yes / A dam break wave caused by the discontinuity in depth and velocity of a flow is resulted from instantaneous release a body of water from a channel and classified naturally as a rapidly varied unsteady flow. Due to its nature, it is hard to be accurately represented by analytical models. The aim of this study is to establish the modelling differences and complexity echelons between analytically simulated explicit laminar and turbulent dry bed dam break wave free surface profiles. An in-depth solution to the free surface profile has been provided and evaluated by representing the reported dam break flow measurements at various locations. The methodology adopted utilizes the free surface profile formulations presented by Chanson 1,2, which are developed using the method of characteristics. In order to validate the results of the presented analytical models in illustrating the dam break wave under dry bed conditions, published experimental data provided by Schoklitsch 3, Debiane 4 and Dressler 5 are used to compare and analyze the performance of the dam break waves under laminar and turbulent flow conditions.

京都大学 / 新制・課程博士 / 博士(工学) / 甲第25237号 / 工博第5196号 / 新制||工||1992(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 原田 英治, 教授 後藤 仁志, 准教授 音田 慎一郎, 教授 山上 路生 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

Submitted by Maicon Juliano Schmidt (maicons) on 2015-06-05T19:08:58Z No. of bitstreams: 1 Rafael Varela Cardoso.pdf: 525156 bytes, checksum: b868ac5540260f0849b69bb32ac76092 (MD5) / Made available in DSpace on 2015-06-05T19:08:58Z (GMT). No. of bitstreams: 1 Rafael Varela Cardoso.pdf: 525156 bytes, checksum: b868ac5540260f0849b69bb32ac76092 (MD5) Previous issue date: 2015-04-09 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente trabalho pretende mostrar como funciona a prática jornalística pela ótica do repórter que cobre política. As condições de produção dos repórteres que trabalham nesta editoria, em emissoras de televisão sediadas em Porto Alegre, devem nos ajudar a compreender o cotidiano dos profissionais. Buscamos investigar a relação entre o pensar jornalismo político nos bastidores e a notícia veiculada na tevê e entender de que forma as condições de produção podem afetar na construção da notícia. Visando uma melhor compreensão de possíveis dificuldades na elaboração de reportagens e dos tensionamentos na produção da notícia, o respectivo trabalho adota a entrevista semiestruturada como procedimento metodológico para o entendimento da prática e explora a cobertura das manifestações de junho de 2013, realizada por estes profissionais. Na compreensão dos entrevistados, trata-se de um engajamento que se deu mais por motivação das massas do que pelo propósito de mudanças. Além disso, a pesquisa aponta que a tevê apresentou dificuldades de entender as manifestações e mostra o descontentamento da maioria dos entrevistados com a forma como as reportagens foram conduzidas. Mostra, ainda, que o descrédito na política é considerável. / The purpose of this study is to show how the journalistic practice works from the perspective of the reporter covering policy. The production conditions of the reporters working in this editorial, in television stations based in Porto Alegre, should help us to understand the daily life of these professionals. We seek to investigate the relation between the thinking of political journalism behind the scenes and the news broadcasted in TV and understand how production conditions can affect the construction of the news. For a better comprehension of possible difficulties in the preparation of reports and tensions in news production, this research uses the semi-structured interview as a methodological procedure for understanding the practice and explores the coverage of the events of June 2013, made by these professionals. According to the respondents, it was an engagement that gave more motivation for the masses than the purpose of change. In addition, the results suggest that TV had difficulties to understand the demonstrations and show the discontent of the majority of interviewees regarding how the reports were conducted. It shows that the desperation inpolitics is considerable.