O presente trabalho apresenta soluções e análises desenvolvidas em estruturas extravasoras em aproveitamentos a fio dágua, envolvendo análises nos critérios de operação de diversos tipos de descarregadores, tais como: soleira normal, labirinto, tulipa e comportas específicas. Para tanto se faz necessário o estudo e comparação de resultados a serem desenvolvidos em cada projeto com relação aos fatores hidráulicos, hidrológicos, geológicos, topográficos e dos riscos envolvendo prejuízos decorrentes de falhas nas estruturas hidráulicas. A avaliação de extravasores labirinto em aproveitamentos hidrelétricos de projetos aprovados pela Agência Nacional de Energia Elétrica ANEEL tem o objetivo de analisar a segurança em relação à construção e à operação, com foco no desenvolvimento de descarregadores adequados para cada estudo de caso presentes neste trabalho. Esta avaliação indica as condições geométricas, econômicas e hidráulicas do extravasor labirinto adequado para cada situação de aproveitamento hidrelétrico a fio dágua. / This paper studies solutions and analysis developed in spillways structures in hydroelectric development trickle, involving analysis of the operation criteria of several types of dischargers, such as threshold normal maze, morning glory and specific gates. For this purpose it is necessary to study and compare the results to be developed in each project about the factors hydraulic, hydrologic, geologic, topographic and risks involving losses due to failures in hydraulic structures. The evaluation of spillways maze in hydroelectric of projects approved by the National Agency of Electric Energy - ANEEL aims to analyze the safety for the construction and operation, focusing on the development of suitable dischargers for each case study in this work. This assessment indicates the geometric, economic and hydraulic conditions of the most suitable spillways maze for each situation of hydroelectric development trickle.

O presente trabalho apresenta soluções e análises desenvolvidas em estruturas extravasoras em aproveitamentos a fio dágua, envolvendo análises nos critérios de operação de diversos tipos de descarregadores, tais como: soleira normal, labirinto, tulipa e comportas específicas. Para tanto se faz necessário o estudo e comparação de resultados a serem desenvolvidos em cada projeto com relação aos fatores hidráulicos, hidrológicos, geológicos, topográficos e dos riscos envolvendo prejuízos decorrentes de falhas nas estruturas hidráulicas. A avaliação de extravasores labirinto em aproveitamentos hidrelétricos de projetos aprovados pela Agência Nacional de Energia Elétrica ANEEL tem o objetivo de analisar a segurança em relação à construção e à operação, com foco no desenvolvimento de descarregadores adequados para cada estudo de caso presentes neste trabalho. Esta avaliação indica as condições geométricas, econômicas e hidráulicas do extravasor labirinto adequado para cada situação de aproveitamento hidrelétrico a fio dágua. / This paper studies solutions and analysis developed in spillways structures in hydroelectric development trickle, involving analysis of the operation criteria of several types of dischargers, such as threshold normal maze, morning glory and specific gates. For this purpose it is necessary to study and compare the results to be developed in each project about the factors hydraulic, hydrologic, geologic, topographic and risks involving losses due to failures in hydraulic structures. The evaluation of spillways maze in hydroelectric of projects approved by the National Agency of Electric Energy - ANEEL aims to analyze the safety for the construction and operation, focusing on the development of suitable dischargers for each case study in this work. This assessment indicates the geometric, economic and hydraulic conditions of the most suitable spillways maze for each situation of hydroelectric development trickle.

In recent years, the general interest in the safety of dams and reservoirs has grown appreciably. This research describes the application and design of labyrinth weirs to improve the performance of existing reservoirs and also to be used for the construction of new dams. The parameters that can affect the performance of labyrinth weirs are discussed. Tests were conducted on normal linear weirs with four different crest shapes to determine the rate of change of discharge coefficient when each type of weir is used. It is found that weirs with rounded-crest shape can pass more flow than other types of weirs when they are subjected to the same total operating head. Two design charts are developed for labyrinth weirs with rounded-crest shape with HT/P ratio ranges from 0.15 to 0.5 and 0.5 to 1.0. The areas of application of labyrinth weirs, design procedure, different cases of design, and a design example are given. In addition, the performance of labyrinth weirs when the structure placed in an angle to the approaching flow (inclined labyrinth weirs) was tested.

Spillways are hydraulic structures that allow dams to release and convey surplus water or flood from the reservoir to the downstream channel. The spillway is a safety structure that prevents the overtopping of the dam. Many dam failure disasters were due to the inadequate capacity of the spillway, which fully illustrates the prominence of spillway design. According to the control structure, spillways can be divided into gated and ungated type. The gated spillway provides better control of the managed water level and reduces the elevation of the top of the dam. Researchers have mostly used experimental models to investigate these two types of spillways in previous literature. In the past few years, following the rapid development of numerical simulation technology, there have been more studies on the numerical modeling of spillways. However, most of the literature was about ungated spillways and most of it considered the case of low head ratios, while the case with gates, especially the case of vertical plane gates, was less investigated. In this study, the hydraulic characteristics, such as velocity, pressure, and discharge coefficient, of the ungated and gated ogee spillways are investigated by means of physical and numerical models for the case of low and high head ratios. The study covered head ratios varying from 1.4 to 4.6 and the relative gate-openings varying from 0.5 to 2. The second main objective of this study was to evaluate the performance of the numerical model to simulate gated and ungated spillways. It mainly employed 2DV OpenFOAM to simulate three turbulence models (realizable k-ε, RNG k-ε, k-ω SST), and the results were compared and calibrated with the experimental results from the physical model tests performed by the author to verify the performance of the numerical model. This study aims to demonstrate that the numerical model can be used as a complementary tool to the physical model to measure the hydraulic performance of ogee spillways.

Os vertedores são estruturas hidráulicas de suma importância no controle de escoamento e também para medição de vazões. Estas estruturas são amplamente utilizadas em aproveitamento múltiplos principalmente como controle de vazão. Neste trabalho é apresentado um histórico dos estudos elaborados para vertedores, demonstrando as principais características entre cada estudo.Também são apresentados os resultados obtidos através dos cálculos de linha d\'água é pressão utilizando as equações para superfícies de fundo curvo para um perfil segundo o equacionamento de Creager e o perfil Cossenoidal proposto por este trabalho. O escoamento realizado em um perfil Cossenoidal apresenta um comportamento muito semelhante ao escoamento realizado em um perfil do tipo Creager. Com a utilização do perfil Cossenoidal foi possível realizar a coincidência de raio de curvatura no trecho da crista onde o raio de curvatura do perfil Cossenoidal ajustado a um perfil do tipo Creager, apresentou o mesmo valor para o raio de curvatura para uma elipse proposta por Maynord modificado por este trabalho. Os resultados de linha d\'água e pressão foram bons e satisfatórios muito semelhantes aos valores já apresentados pelas soleiras convencionais (Creager e Maynord). / The spillways are hydraulic structures very important in the control flow and for measuring flow rates. These structures are widely used mainly for multiple use flow control. This work presents a history of the studies prepared for spillways, showing the main features of each study. It is intended to study a cosinusoidal profile through a mathematical model seeking to obtain satisfactory answers to the water lines and pressure for the studied profile. Showing the results obtained through the water level and pressure calculations, using the equations for curve surface for a Creager\'s profile and Cossenoidal\'s profile suggest in this work. The flow realized in a Cossenoidal\'s profile show a behavior similar at the flow realized in a Creager\'s profile. The utilization of the Cossenoidal\'s profile was possible to realize the coincidence of the curvature radius in the crest between Cossenoidal\'s profile and Maynord Modified ellipse, and this profile was adjusted with a Creager\'s profile and Maynord\'s ellipse. The results of water level and pressure showed goods and satisfactory, very similar with the values showed in other studies for a conventional weirs (Creager and Maynord).

Os vertedores são estruturas hidráulicas de suma importância no controle de escoamento e também para medição de vazões. Estas estruturas são amplamente utilizadas em aproveitamento múltiplos principalmente como controle de vazão. Neste trabalho é apresentado um histórico dos estudos elaborados para vertedores, demonstrando as principais características entre cada estudo.Também são apresentados os resultados obtidos através dos cálculos de linha d\'água é pressão utilizando as equações para superfícies de fundo curvo para um perfil segundo o equacionamento de Creager e o perfil Cossenoidal proposto por este trabalho. O escoamento realizado em um perfil Cossenoidal apresenta um comportamento muito semelhante ao escoamento realizado em um perfil do tipo Creager. Com a utilização do perfil Cossenoidal foi possível realizar a coincidência de raio de curvatura no trecho da crista onde o raio de curvatura do perfil Cossenoidal ajustado a um perfil do tipo Creager, apresentou o mesmo valor para o raio de curvatura para uma elipse proposta por Maynord modificado por este trabalho. Os resultados de linha d\'água e pressão foram bons e satisfatórios muito semelhantes aos valores já apresentados pelas soleiras convencionais (Creager e Maynord). / The spillways are hydraulic structures very important in the control flow and for measuring flow rates. These structures are widely used mainly for multiple use flow control. This work presents a history of the studies prepared for spillways, showing the main features of each study. It is intended to study a cosinusoidal profile through a mathematical model seeking to obtain satisfactory answers to the water lines and pressure for the studied profile. Showing the results obtained through the water level and pressure calculations, using the equations for curve surface for a Creager\'s profile and Cossenoidal\'s profile suggest in this work. The flow realized in a Cossenoidal\'s profile show a behavior similar at the flow realized in a Creager\'s profile. The utilization of the Cossenoidal\'s profile was possible to realize the coincidence of the curvature radius in the crest between Cossenoidal\'s profile and Maynord Modified ellipse, and this profile was adjusted with a Creager\'s profile and Maynord\'s ellipse. The results of water level and pressure showed goods and satisfactory, very similar with the values showed in other studies for a conventional weirs (Creager and Maynord).

Today scale models are used to design spillway structures for hydropower stations. These are expensive and time-consuming to build and alter. This study investigates the possibilities of using numerical simulations in order to facilitate the spillway design process. It would be possible to save time and resources by altering the spillway parameters in the numerical model and thus find an optimal design, which can be further investigated with a scale model. However, it is complicated to simulate turbulent flows. Therefore the simulated flows in this study are compared to experimental measurements in order to investigate the accuracy of the numerical model. Ansys software Fluent uses Computational Fluid Dynamics (CFD) to calculate turbulent flows and is used as the simulation tool in this study. The simulations were performed on the spillway system of Shuibuya hydropower station. There are five spillway channels with flip bucket terminals and high head. In order to investigate the risk of erosion during large flows the jet throw distance was examined in experiments on a scale model. The same parameter was investigated in this simulation study. The acceptable error margin was set 30 % for the comparison between simulated and experimental measurements. All performed simulations met this criterion. It was therefore concluded that Fluent could be used as a sufficiently good approximation tool when it comes to turbulent flows in spillways.

The latest spillway in Bergeforsen was finished in 2014. It has a 25 metres wide spillway opening capable of discharging 1500 m^3/s at full reservoir retention level. The overflow chute ends in a 35 metres wide and 100 metres long stilling basin which then converges into 25 metres wide curved tunnel leading the water flow under a railway and back into the river. During the winter, the water in the stilling basin and the tunnel freezes, creating an ice cover all the way through the channel and limiting the water passage in the tunnel. For thinner ice covers, the channel can be flushed by discharging water into the spillway, but there are concerns that a colder winter might result in a ice cover of significant thickness, not prone to cracking at water discharges. This could result in water masses flowing on top of the ice cover into an ice covered tunnel leaving it at risk of being pressurized, posing some serious safety threats to the tunnel. This report presents a full-scale 3D model of the spillway with an ice cover as well as both transient and steady-state simulation results for several discharges to examine the effect of an impenetrable ice cover in the channel. The model is verified using American Society of Mechanical Engineers policy complete with an grid convergence index study. It was found that there was no risk for pressurized flow in the tunnel. However, serious wave-run ups was observed at the tunnel entrance and in the tunnel. / <p>Slutrapporten i projektkursen F7042T (15 hp) på civilingenjörsprogrammet i Teknisk fysik och elektroteknik (INTE EXJOBB).</p>

Orientador: Ana Inés Borri Genovez / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-17T09:38:36Z (GMT). No. of bitstreams: 1 Silva_LucianaVasquesCorreiada_M.pdf: 4691353 bytes, checksum: 05ef8f206bb1957c550c8b6cee57b065 (MD5) Previous issue date: 2007 / Resumo: A preocupação com o aprimoramento das técnicas de segurança de barragens tem sido cada vez mais discutida, devido ao aumento de incidentes ocorridos com estas estruturas situadas em locais densamente habitados. O objetivo deste trabalho é determinar a viabilidade técnica de uso do vertedor de emergência de vegetação em pequenas barragens de material solto. Para atingir este objetivo o dimensionamento foi realizado através do equacionamento básico e usando um modelo numérico, para dois tipos diferentes de cobertura vegetal. O uso de grama Bermuda com maior uniformidade, resultou numa menor descontinuidade na superfície de contato com o escoamento e menor probabilidade de erosão no canal. Este fato combinado com as dimensões resultantes para o canal permitem sugerir o uso deste tipo de cobertura vegetal. Os resultados indicaram que o vertedor de emergência de vegetação mostrou-se viável e uma alternativa eficiente para aumentar a segurança de barragens de material solto, apresentando construção simples e baixo custo, além de causar baixo impacto ao ambiente, sendo esteticamente melhor e adaptando-se às condições naturais da região de implantação da obra. A manutenção e diretrizes de inspeção devem proporcionar o bom funcionamento do vertedor de vegetação / Abstract: The concern about an enhancement of safety techniques for dams has been discussed more and more, due to an increase of the number of incidents that happened with structures located in places densely inhabited. The objective of this work is to establish the technical viability of using a vegetated emergency spillway in small embankment dams. To achieve such objective the design was done using a basic set of equations and a numerical model, for two different kinds of vegetation. The use of Cynodon dactylon grass with a bigger uniformity, resulted in a smaller discontinuity of the surface in touch with the flow and a smaller probability of having an erosion of the channel. Such factors, and the channel resulting dimensions, allow us to suggest the use of such vegetation cover. The results showed the viability of the emergency spillway with vegetation and also an efficient alternative to increase the safety of embankment dams, with inexpensive and easy construction, besides of causing a low environmental impact, also being esthetically best and adapting to the surrounding natural conditions. The maintenance and directions of inspection must provide a good operation of the vegetated spillway / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil

Please read the abstract in the dissertation. / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Civil Engineering / Unrestricted